KS3 Science Revision Worksheets Standard Edition · 2020. 3. 19. · KS3 Science Revision...

KS3 Science Revision Worksheets Standard Edition P. Hill, Beaver Educational Resources 2001. Registered to Edenham High School. CR0 7NJ.

KS3 Science Revision Worksheets

Standard Edition

ISBN 0 9537409 5 1

Introduction.

The aim of this resource is to provide pupils with a complete revision guide forthe Key Stage 3 Science programme of study. There are ninety two worksheetscovering every National Curriculum Statement of Attainment at KS3.

Each sheet provides pupils with the key facts of a topic and also contains oneor more short exercises which have been designed to check pupils’ knowledgeand understanding. The sheets can be used in a variety of ways:

• to provide high quality classwork and homework materials

• for end of topic revision

• to provide pupils with the key facts of a topic that they have missed.

P. Hill. BSc.

Copyright notice Beaver Educational Resources 2001. The material in this publication is copyright. It may only beduplicated for use by the purchasing school.


CONTENTS

2.1. Cells and cell functions. pg.Worksheet 1 – Life processes …..……..……………………….…………5Worksheet 2 – Plant and animal organs ….…………………….………...6Worksheet 3 – Animal and plant cells ……………..………….………….7Worksheet 4 – Different cells for different jobs ……….…………………8

2.2. Humans as organisms.Worksheet 5 – A balanced diet …...……..………………….…………….9Worksheet 6 – Food and digestion …..………………………………….10Worksheet 7 – Stages of digestion ……………….………..….…………11Worksheet 8 – Blood ……………………………………….…..……….12Worksheet 9 – The blood system …………………………………….….13Worksheet 10 – Moving the body …..…………………………...…..….14Worksheet 11 – Growing up …………………………………………….15Worksheet 12 – The human reproductive system………………………..16Worksheet 13 – The menstrual cycle …..………………………………..17Worksheet 14 – Ovulation and fertilisation ……………….…………….18Worksheet 15 – The developing baby …………….……...…………….19Worksheet 16 – Breathing (1) …..…………………….……………...….20Worksheet 17 – Breathing (2) …..…………………….……………...….21Worksheet 18 – Keeping the lungs clean ……………….…………...….22Worksheet 19 – Respiration …..…………………………..……………..23Worksheet 20 – Drugs and health …………………...…….…………….24Worksheet 21 – Germs and health .………………..……...……………..25Worksheet 22 – Fighting germs …..……………………………………..26

2.3. Green plants as organisms.Worksheet 23 – Photosynthesis …..……………………………………..27Worksheet 24 – Plant nutrition ……………………...…….………….…28

2.4. Variation, classification and inheritance.Worksheet 25 – Classification – plants without flowers …………….….29Worksheet 26 – Classification – flowering plants …..…………………..30Worksheet 27 – Animals without backbones (1) ……..…...…………….31Worksheet 28 – Animals without backbones (2) ……..…...…………….32Worksheet 29 – Animals with backbones …………….....……..……….33Worksheet 30 – Variation …………...…..…...…………………....…….34Worksheet 31 – Selective breeding ……..…...…………………....…….35

2.5. Living things in their environment.Worksheet 32 – A place to live ………………………....……………….36Worksheet 33 – Changing habitats ……………….....…….………….…37Worksheet 34 – Food chains and pyramids of numbers ………………..38Worksheet 35 – Food webs ……..….…………………..………………..39Worksheet 36 – Poisoned food chains ……….……….......………….….40Worksheet 37 – Populations ……………..…...…………….……..…….41

Worksheets 1-37 – Attainment target 2. Life Processes and Living Things.


3.1. Classifying materials. pg.Worksheet 38 – Solids liquids and gases …………………….……42Worksheet 39 – Changes of state ………………………..….…….43Worksheet 40 – Elements …..…………………………….….…….44Worksheet 41 – The periodic table ………….……………….……45Worksheet 42 – Compounds …………...………………..….…….46Worksheet 43 – Separating mixtures …………………….….…….47Worksheet 44 – Metals and non-metals ………………….….…….48

3.2. Changing materials.Worksheet 45 – Changes of state ……………………….….….…..49Worksheet 46 – Solubility ………………….…………….….…….50Worksheet 47 – Expansion …….….…………………………….....51Worksheet 48 – Rocks and weathering ………….……….….…….52Worksheet 49 – The rock cycle …….….………………….…….....53Worksheet 50 – Types of rock …………….…….……….….…….54Worksheet 51 – Chemical reactions …….….……………..…….....55Worksheet 52 – Types of chemical reaction ……….…….….…….56Worksheet 53 – Burning ……………………..…….…….….…….57Worksheet 54 – Products from chemical reactions ……….…….....58Worksheet 55 – Harmful chemical reactions …………….….…….59Worksheet 56 – Energy from chemical reactions ……………...….60

3.3. Patterns of behaviour.Worksheet 57 – Reactivity of metals …………….…….………….61Worksheet 58 – Displacement reactions …….….………………....62Worksheet 59 – Acids and alkalis ………………….…….….…….63Worksheet 60 – Acids and metals ……………………..….…….....64Worksheet 61 – Acids and bases …………..…………..….…….....65Worksheet 62 – Neutralisation ………………………..….….…….66Worksheet 63 – Acid rain ……………………………………...….67

Worksheets 38- 63 – Attainment target 3. Materials and their properties.


4.1. Electricity and magnetism. pg.Worksheet 64 – Electric current and voltage …….….………….....68Worksheet 65 – Series and parallel circuits …………..….….…….69Worksheet 66 – Electrical resistance ……...…………..….…….....70Worksheet 67 – Magnets ………….…………………..….….…….71Worksheet 68 – Electromagnets ……………...………………...….72Worksheet 69 – Uses of electromagnets …………..…………...….73

4.2. Forces and motion.Worksheet 70 – Speed ……………………………….………….....74Worksheet 71 – Force and movement ………….……..….….…….75Worksheet 72 – Friction ……...…………..….……………….........76Worksheet 73 – Turning forces ………….……..……..….….…….77Worksheet 74 – Moments …………..……………..…………...….78Worksheet 75 – Pressure …………………………..…………...….79

4.3. Light and sound.Worksheet 76 – Reflection …………….……….……..….….…….80Worksheet 77 – Refraction of light ……..…...…………..….…......81Worksheet 78 – The spectrum …..……….……..……..….….…….82Worksheet 79 – Coloured objects in coloured lights …...……...….83Worksheet 80 – Hearing .…………………………..…………...….84Worksheet 81 – Sound .…………………………..………..…...….85Worksheet 82 – Comparing light and sound ……..………..…...….86

4.4. The Earth and beyond.Worksheet 83 – Day and night ………….…...…………..….…......87Worksheet 84 – The seasons …..……….……....……..….….…….88Worksheet 85 – The solar system …...…………………….…...….89Worksheet 86 – Satellites .……………………………………...….90Worksheet 87 – The Moon and its phases .……....………..…...….91

4.5. Energy resources and energy transfer.Worksheet 88 – Energy resources ………….…...…………..…......92Worksheet 89 – The Sun and energy resources …..…..….….…….93Worksheet 90 – Generating electricity …...…………….….…...….94Worksheet 91 – Energy transfer .………….…………….....…...….95Worksheet 92 – Conservation of energy …..……….....….….…….96

Worksheets 64-92 – Attainment target 4. Physical processes.

Answers to exercises – pages 97-108.


Movement This is easier to see in animals than in plants. Plants move very slowly as they grow.

Respiration Obtaining energy by reacting food with oxygen.

Sensitivity Sensing changes around them and then responding.

Growth Food is used to build up the parts of the body.

Reproduction Producing offspring (young).

Excretion Getting rid of poisonous waste chemicals that have been made inside the body.

Nutrition Plants make their own food by a process called PHOTOSYNTHESIS. Animals mustfeed on plants or other animals.

All plants and animals carry out seven processes in order to stay alive. The table below shows theseseven LIFE PROCESSES.

Use the name MRS. GREN as an easy way to remember all 7 life processes.

Exercise 1 – Complete the sentences below.

1) Living organisms must show all 7 ______________________________

2) It is usually easier to see movement in animals than in plants because ______________________

_____________________________________________________________________________

3) The process of respiration produces _______________ for the body.

4) Our ears, eyes and nose are some of the organs that give us ___________________

5) If living organisms did not __________________ they would soon become extinct (die out).

6) We excrete the waste gas ___________________________ by breathing it out.

7) The kidneys _______________ a waste chemical called urea.

Exercise 2 - A motor car moves but it is not living. Complete the two lists below to show which processesit does and does not show.

Processes a car does show Processes a car does not show

movement growth

nutrition (takes in petrol) …………………………

………………………… …………………………

…………………………

W.S.1. Life processes. Name ………….……………………...


W.S.2. Plant and animal organs. Name ………….……………………...

Exercise 1 - Fill in the missing words in the passage below. Choose from the list of words at the bottom.

In the human body many cells of the same .................... join together to form TISSUES. Thesetissues then join together to form more complicated structures called .................... An organ is a partof the .................... that has one or more important ........................ (jobs) to carry out. All of theorgans work together to keep the body ................... The bodies of most animals and .................... aremade up of many organs. Several organs working together on one large task is called a ....................For example, in the human body the mouth, gullet, stomach and .................... make up the digestivesystem.

intestines type organs plants functions body healthy system

Exercise 2 – The diagrams below show various human and plant organs. Write the correct descriptionunderneath each one. Choose the descriptions from the list at the bottom of this page.

...................................... ...................................... ......................................

...................................... ...................................... ......................................

...................................... ...................................... ......................................

DescriptionsThe stomach plays an important part in digesting food.The leaf is the organ that makes food for the plant.The brain controls the activities of the rest of the body.The flower is the organ of reproduction in plants.The lungs take in oxygen gas from the air and pass out carbon dioxide.The heart pumps blood to every part of the body.

...................................... ...................................... ......................................

...................................... ...................................... ......................................

...................................... ...................................... ......................................


vacuole

chloroplast

cell wall

cytoplasm

cell membrane

nucleus

Plant cell

Animal cell

W.S.3. Animal and plant cells. Name ………………………………...

Exercise 1 – Fill in the missing words in the passage below. Choose from the list of words at the bottom.

The bodies of all plants and ……………….. are made up of tiny living units called………………. Some microscopic organisms consist of only a ……………….. cellbut the bodies of most plants and animals are made up of ……………….. of cells.There are many different ……………….. of plant and animal cells. The diagramsbelow show the ……………….. that they usually contain.

parts animals cells types millions single

Exercise 2 – Study the two lists below and then join up each cell part with its function. Use the diagramsabove to help you.

Cell part Function (job)

Nucleus covers the membrane and gives strength to a plant cell.

Cytoplasm controls what the cell does.

Cell wall a jelly that fills the cell, chemical reactions happen here.

Chloroplast stores water in a plant cell.

Vacuole absorbs light energy in order to make food for the plant.


W.S.4. Different cells for different jobs. Name ………….……..……….


Nearly all cells contain a membrane, ……………….. and cytoplasm. However thereare many ……………….. types of cells. They vary in their ……………….. and sizedepending on their functions (jobs). Each type of cell is well ……………….. (suited)to its function. In the human ……………….. there are about twenty different types ofcell, each has a certain ……………….. to do. This makes the body work much more……………….. than if each cell was trying to do everything.

efficiently different nucleus shape body adapted job.

Exercise 2 – The diagrams below show how some cells are adapted to their functions. Study them carefullyand then join up each cell with its correct description.

Palisade cellThis cell is found on the upper surface of a leaf. Itcontains many tiny discs called chloroplasts.These contain a green chemical called chlorophyllwhich absorbs sunlight during photosynthesis.

Sperm cellThis is made of 3 parts. The head contains thenucleus which enters the ovum duringfertilisation. The middle part contains an energystore which powers the tail during swimming.

Root Hair cellThis is found on the surface of a root. Its functionis to absorb water from the soil. Part of the cell isdrawn out into a long hair-like structure. Thisincreases the surface area for water absorption.

Ciliated cellThis cell is found lining the trachea (windpipe).Its surface is covered with tiny hair-like stucturescalled cilia. These waft dirt and germs upwards tothe throat.


Food type Foods rich in this

Carbohydrate Starchy and sugary foods, e.g. potato, bread, cereals and cakes.

Protein Meat, fish, eggs, cheese, milk and nuts.

Fat Vegetable oils, butter, lard, cream, cheese and some meats.

Vitamins Fresh fruit and vegetables.

Minerals A wide range of foods, e.g. iron from meat and calcium from milk.

Fibre Cereals, fruit and vegetables.

W.S.5. A balanced diet. Name ……………………………………


In order to stay .................... the body needs seven basic chemicals which are called food.................... These are carbohydrates, proteins, .................., minerals, vitamins, fibre and water. Abalanced diet contains the .................... amounts of all seven food types. Carbohydrates are sugarsand .................... They are a quick energy source for the body. Fats also give us .................... butthey release it much more slowly. Stored fat under the skin helps to keep us .................... and it alsoacts as an energy store. We need .................... to help us grow and to .................... damaged parts.Minerals and .................... are needed in smaller amounts to keep the body healthy. Fibre orroughage helps to keep the food moving along the .................... People who do not eat enough fibresometimes become constipated.

intestines types fats warm correct protein starch healthy repair energyvitamins.

Exercise 2 – Study the pictures below and then write down the main FOOD TYPES that each one contains.

_________________ __________________ ___________________ __________________

_________________ __________________ ___________________ __________________


W.S.6. Food and digestion. Name …………………………………


The body needs food for several different reasons. We need food in order to grow and to……………….. worn out or damaged parts. Food is also used as a ……………….. duringrespiration. The energy from food is used for movement, producing ……………….. and to keep allof the parts working properly. Before the body ……………….. can use the food we eat it must passinto the blood. The food is broken down into very small soluble molecules by the ………………..system. These molecules then pass through the walls of the ……………….. and into the blood.

intestines heat repair cells digestive fuel

Exercise 2 - Study the diagram below of the human digestive system and then carefully add the labels bychoosing from the list at the bottom of this page.

tongue salivary gland liver gall bladder small intestine gullet pancreas

stomach large intestine appendix rectum anus


Organ Description

Here the food is chewed and moistened with saliva. The food is shapedinto a round ball called a BOLUS before it is swallowed.

This is a muscular tube that squeezes the food bolus down to the stomach.

This is a muscular bag that contains gastric juice and hydrochloric acid. Itcontracts and relaxes to churn up the food. Gastric juice contains anenzyme that digests protein. The acid kills germs.

This is a very long muscular tube which the partly digested food passes intoafter it leaves the stomach. Here the food is completely digested and thenit is absorbed through the walls and into the blood stream.

This is a small leaf-shaped organ. It makes a fluid called pancreatic juicewhich passes into the small intestine. This fluid contains an alkali thathelps to neutralise the acid from the stomach. Pancreatic juice alsocontains several enzymes which help to complete digestion in the smallintestine.

This organ makes a chemical called BILE which is stored in a small bagcalled the GALL BLADDER. The bile is squeezed into the small intestinewhere it helps to break up large pieces of fat.

This is a wider tube that the undigested waste food material passesthrough. Water is absorbed from this waste back into the body.

This organ has no function in humans but it helps with digestion of plantmaterial in herbivores such as sheep. It sometimes becomes infected inhumans and then it must be removed.

The dried out waste food material is stored here until it is ready to bepassed out of the body through the anus.

W.S.7. Stages of digestion. Name …………………………………

Solid pieces of food are gradually broken down into small soluble molecules by our digestivesystem. The food is broken up by chewing in the mouth and by churning of the stomach muscles.Hydrochloric acid in the stomach kills any germs and also helps to dissolve the food. As the foodpasses through the rest of the digestive system special chemicals called ENZYMES break up largefood molecules into smaller ones. These molecules then seep out into the blood through tiny poresin the walls of the small intestines. Any undigested waste material enters the large intestine wherewater is absorbed back into the blood. The solid waste is then passed out of the body.

What to doThe table below gives descriptions of organs of the human digestive system. Read each description and thenwrite down the name of each organ in the left hand column. Use the words at the bottom of this page.

liver small intestine gullet pancreas stomach large intestineappendix mouth rectum.


Part of blood What it does

PLASMA This is a pale yellow liquid in which the blood cells float.It carries:• waste carbon dioxide from the cells to the lungs;• dissolved food to the cells;• waste urea from the liver to the kidneys;• hormones from one part of the body to another.

RED CELLSThey do not have a nucleus and they are very numerous.They contain a red pigment called HAEMOGLOBIN whichcombines with oxygen to form OXYHAEMOGLOBIN. Thisis how oxygen is carried from the lungs to the cells.

WHITE CELLSThey do have a nucleus.They fight against germs that enter the blood.

PLATELETSThese are small pieces of cells.They do not have a nucleus.They help blood to clot if the skin is cut.

W.S.8. Blood. Name ………………………………….

In humans it is the blood that transports (carries) substances around the body. The followingsubstances are transported in the blood :-

water, digested food, salts, hormones, oxygen, carbon dioxide, urea.

The table below shows what the blood is made of and the function of each part.

Exercise - Fill in the missing words in the passage below. Choose from the list of words at the bottom.

Blood is made of a pale yellow liquid called .................... and two different types of blood cell,white blood cells and ................. blood cells. Most of the chemicals in the blood are .................... inthe plasma. .................... is carried by the red blood cells. There are two types of ....................blood cells. These help to destroy any .................... (bacteria and viruses) which may enter the body.There are also tiny pieces of cells in the blood called .................. These help to clot the blood if theskin is .................. If the body was not able to make a .................... we would be in danger ofbleeding to death from even the smallest of cuts.

plasma cut scab red dissolved germs oxygen platelets white


W.S.9. The blood system. Name ………………………………….

Exercise - Fill in the missing words in the passage below. Use the diagram at the bottom of this page to helpyou. Choose from the list of words underneath.

The blood travels around the body inside tubes called blood ……………….. The three types ofblood vessel are arteries, ……………….. and capillaries. The heart is a muscular ………………..that squeezes blood into the arteries. The blood has to travel all the way around the………………..This is why the blood must be under a high pressure. The veins carry the bloodback to the ……………….. The capillaries are very ……………….. blood vessels with walls onlyone ……………….. thick. It is at the capillaries that substances are passed between the……………….. and the cells of the body.

vessels pump heart blood veins body narrow cell

Aorta(main artery)

Pulmonary veinPulmonary artery

Vena cava(main vein)

Lungs

Heart

Body


Fibres

W.S.10. Moving the body. Name ………………………………….

In order to move the skeleton has JOINTS in between many of its parts. The movements are madeby muscles which pull on the bones. Muscles CONTRACT (shorten) in order to pull. A muscle ismade up of many thin fibres. Each fibre shortens when the muscle contracts.

Relaxed muscleMuscle fibres are restingand appear long and thin.

Contracted muscleEach muscle fibre hasshortened and thickened.

Tendon

Many joints act like hinges with a pair of muscles producing the movements. A muscle cannotpush, it can only pull on a bone. This is why a pair of muscles are needed at a joint. One musclepulls the joint in one direction and the other pulls the joint back.

Lowering arm Raising arm

Biceps musclerelaxes

Biceps musclecontracts

radius

ulna

humerus

Triceps musclecontracts Triceps muscle

relaxes

Exercise - Fill in the missing words in the passage below. Use the diagrams above to help you. Choose fromthe list of words at the bottom.

There are ……………….. in between parts of the skeleton which allow it to ……………….. Themovements are made by ……………….. which pull on the bones. A muscle is made up of manythin strands called ……………….. When a muscle contracts each fibre ……………….. Musclesare attached to bones by ……………….. These are tough cords that do not stretch. Muscles canonly pull they cannot ……………….. Therefore muscles work in ……………….. in order to movea joint in both directions. If we wish to lift a weight our ……………….. contracts. To lower thearm the biceps relaxes and the ……………….. contracts.

triceps shortens biceps move fibres tendons muscles push joints pairs


Changes in boys at puberty Changes in girls at puberty

1) The testes begin to make sperms.2) A hormone called TESTOSTERONE is produced by the testes.3) The larynx (voice box) grows larger which makes the voice deeper – voice breaks.4) Hair grows on the face and body.5) The body becomes more muscular.6) Changes in attitude and behaviour.

1) The ovaries begin to produce ova.2) A hormone called OESTROGEN is produced by the ovaries.3) The monthly menstrual cycle starts.4) The breasts begin to develop.5) The hips widen.6) Hair grows on parts of the body.

Changes at puberty Boys Girls

The breasts grow larger.The shoulders grow broader.Hair grows under the arm pits.The hips grow broader.The body becomes more muscular.The monthly periods start.The voice breaks and becomes deeper.Hair grows around the sex organs.The hair and skin become more greasy.Sperms are produced.Ova are produced.Feel attracted to the opposite sex.

W.S.11. Growing up. Name ………………………………….

Puberty is the time when a child’s body begins to change into an adult’s. In boys it begins betweenthe ages of about 12-14 years. In girls puberty begins a little earlier, between the ages of about 11-13 years. At this time special chemicals called SEX HORMONES are released into thebloodstream. These chemicals cause many of the changes that happen in the body. Emotionalchanges also happen at this time.


All ……………….. eventually grow up to be men and women. The time when the body is changingis called ……………… Changes happen all over the ……………….. Emotional changes alsohappen at puberty and we feel ……………….. to the opposite sex. A ……………….. calledtestosterone is made by the testes in a boy and this causes some of the ……………….. in his body.In a girl the ovaries make a hormone called ……………….. which causes many of the changes inher body.

body changes oestrogen hormone puberty children attracted

Exercise 2 - In the table below there is a list of changes which happen at puberty. Tick the right handcolumns to show which changes happen to boys, girls or both.


W.S.12. The human reproductive system. Name …………………………

Just as in animals, the human body has special organs for the purpose of reproduction. Thediagrams below show the male and female reproductive systems.

The male reproductive system

glands

epididymis

sperm duct

testis

penis

urethra

scrotum

The female reproductive system

oviduct(fallopian tube)

ovary

vagina

funnel

uterus uterus walldeveloping ovum

Exercise - Study the diagrams above and then fill in the missing words in the passage below. Choose from thelist of words at the bottom.

In the man the testes make the ………………..cells. The sperms are then stored in a coiled tubecalled the epididymis which lies on the ……………….. of the testis. The ……………….. becomeserect during sexual intercourse. The sperms are carried through a long ……………….. called thesperm duct to the top of the penis. Here glands produce fluids that help the sperms to ………………..The urethra is a tube that carries sperms and ……………….. out of the body.In the woman the ovaries make the ……………….. (egg cells). One ovum is produced every……………….. The ovum is carried along the ……………….. (fallopian tubes) down towards theuterus (womb). The uterus protects the developing baby A special organ called the ………………..grows in the uterus wall during pregnancy. This supplies the developing baby with ………………..and oxygen.

outside urine ova food sperm tube month swim oviducts placenta penis


2

W.S.13. The menstrual cycle. Name ………………………………….

Once every month a woman’s body releases an ovum into the oviduct (fallopian tubes). If there aresperm cells in the oviduct the ovum may join with one of them. The fertilised ovum then travelsdown to the uterus where it grows into a baby. Usually the ovum is not fertilised and it dies. Thewoman has her period when the lining of the uterus breaks down and blood and dead cells pass outthrough the vagina. This process is also called MENSTRUATION. The diagram below shows whathappens during a woman’s monthly cycle.

1

During the week after ovulation thelining of the uterus becomesthicker as many blood capillariesgrow in it. This prepares the uterusto nourish the fertilised ovum.

3If the ovum is not fertilised the thick uterus liningbreaks down about 14 days after ovulation. Bloodand dead cells pass out through the vagina.

During the first 2 weeks the ovum developsinside the ovary and the uterus lining repairsitself. On about day 14 ovulation happens.

Exercise - Use the diagrams and information above to complete these sentences.

1) Only one ovum is released every _________________________

2) Ovulation happens after about ___________________________

3) To help nourish the fertilised ovum the uterus lining ___________________________________

_____________________________________________________________________________

4) If the ovum is not fertilised it will __________________

5) Menstruation is when ___________________________________________________________

_____________________________________________________________________________


3 CELL DIVISION2 FERTILISATION

W.S.14. Ovulation and fertilisation. Name ………………………………….

There are thousands of tiny undeveloped ova (eggs) inside each ovary. Every month one of thesedevelops into an ovum. The ovum is then released into the oviduct (OVULATION). If there aresperm cells in the oviduct the ovum may join with one of them. This is called FERTILISATION.The fertilised ovum then travels down to the uterus where it grows into a baby. The diagram belowshows what happens to the ovum after it is released from the ovary if it is fertilised.

Sperms swim upthe oviducts.1

4 The egg divides further intoa ball of cells and implants intothe lining of the uterus.

Glands and blood vesselsline the wall of the uterus.

Muscular outer wall ofthe uterus.

Developing ova.

ovary

oviduct

OVULATION

Exercise – Use the diagram and information above to help you to complete the sentences below.

1) O……………….. means when the ovum is released from the ovary.

2) The joining of the ovum and sperm is called F………………..

3) Fertilisation usually happens in the O………………..

4) After fertilisation the egg begins to D…………..

5) The egg develops into a ball of C……….

6) The baby develops in the U…………

7) The wall of the uterus contains M…………

8) The lining of the uterus contains B………… V…………


umbilical cord

W.S.15. The developing baby. Name ………………………………….

The mother’s body provides everything that the developing baby needs, which is mainly food andoxygen. The mother’s body also removes all of the waste chemicals such as carbon dioxide andurea from the baby. The PLACENTA is a special organ that develops in the wall of the uterus forthe purpose of exchanging all of these chemicals. The baby is attached to the placenta by theUMBILICAL CORD. This contains blood vessels carrying chemicals to and from the baby. In thefirst stage of development the baby is called an EMBRYO. By the time it reaches 9 weeks old itlooks like a tiny human being and it is then called a FOETUS. The diagram below shows how thedeveloping foetus is connected to the mother’s body and how chemicals are exchanged.

placenta

uteruslining

Mother’s blood carriesfood and oxygen.

Food and oxygen has beentaken out and waste added.

Foetal blood carrieswaste chemicals. Itneeds food andoxygen.

Foetal blood has lostwaste chemicals andhas picked up foodand oxygen.

amnion

foetal bloodvessels


The foetus is surrounded by a bag of fluid called the ......................... which protects it from anyknocks the mother might receive. The umbilical artery carries blood out of the foetus and into the......................... In the placenta the foetal blood passes through many fine vessels which aresurrounded by the mother’s ......................... It is here that waste ......................... pass from thefoetus to the mother. Useful chemicals such as food and ......................... pass into the foetal bloodfrom the mother. While she is pregnant the mother needs to take in more food and oxygen and passout the baby’s ......................... as well as her own.

waste placenta amnion chemicals blood oxygen


W.S.16. Breathing (1). Name ………………………………….

Most living organisms need oxygen gas in order to make energy in the process of RESPIRATION.Humans have special organs called lungs in order to absorb enough oxygen from the air. The lungsalso excrete waste carbon dioxide gas when we breathe out. The diagram below shows the structureof the lungs.

larynx (voice box)

left lung

trachea (wind pipe)

Rings of cartilagekeep trachea open.

right bronchus

alveoli(air sacs)

bronchiole

Blood carrying waste carbondioxide enters the lungs andflows around the alveolus.

Carbon dioxide has passed intothe alveolus. Blood leaving thelungs contains oxygen.

A single alveolus(air sac)

Blood capillary


The function of the lungs is to absorb ……………….. gas and to excrete waste carbon dioxide. Theair is drawn in through the ……………….. which is kept open at all times by rings of a bonymaterial called ……………….. The trachea divides into the right and left ……………….. whichbranch out into narrower tubes called bronchioles. The bronchioles end in microscopic air sacscalled ……………….. The alveoli have very thin walls and are surrounded by ………………..Here oxygen is absorbed into the ……………….. and carbon dioxide passes into the alveoli.

trachea oxygen capillaries cartilage bronchus alveoli blood


W.S.17. Breathing (2). Name ………………………………….

The lungs are in the THORAX (chest). They are separated from the ABDOMEN (lower part of thebody) by a sheet of muscle called the diaphragm. The diagrams below show how we inhale(breathe in) and exhale (breathe out).

INCREASE IN VOLUMECAUSES A DECREASEIN PRESSURE

Exhaling (breathing out).

DECREASE IN VOLUMECAUSES AN INCREASEIN PRESSURE

Inhaling (breathing in).

Muscles between the ribscontract to pull the rib cageupwards and outwards.

The muscles relaxwhich causes therib cage to fall.

The diaphragm contractsand it pulls downwards.

The diaphragm relaxesand it bulges upwards.

Air is drawninto the lungs.

Air is forced outof the lungs.

ribs

Exercise - Use the information and diagrams above to help you to complete the sentences below.

1) The T ___________ means the chest.

2) The diaphragm is a sheet of M ___________

3) The word I ___________ means to breathe in.

4) The word E ___________ means to breathe out.

5) The diaphragm and rib muscles both C ___________ during inhaling.

6) The V ___________ of the thorax increases when we inhale.

7) Air is drawn into the lungs due to a D ___________ in pressure.

8) The diaphragm and rib muscles both R ___________ during exhaling.

9) Air is forced out of the lungs due to an increase in P ____________


Flow of mucus andtrapped germs.Magnified section of trachea.

W.S.18. Keeping the lungs clean. Name ………………………………….

Your nose, trachea (wind pipe) and the air tubes inside the lungs are lined with special cleaningcells and a thick, sticky liquid called MUCUS. This traps dirt and germs in the air you breathe. Thecleaning cells have tiny hairs called CILIA on their surface. These hairs waft the dirty mucus up toyour throat where it is swallowed. Any germs are killed by the acid in the stomach. The diagrambelow shows how this cleaning system works.

ciliated cell

mucus celldirty mucus

cilia

lungs

The effects of smoking on the lungs.

Cigarette smoke stops the cilia from beating. This results in a build up of dirty mucus in the airtubes. This can lead to chest infections and people who smoke often develop a nasty cough whichhelps to bring up the dirty mucus. The smoke can make the air tubes swollen and sore. This is calledBRONCHITIS and a person may cough so much that eventually the tiny alveoli (air sacs) aredestroyed. Cigarette smoke also contains a poisonous gas called carbon monoxide which stops theblood carrying as much oxygen around the body. This can cause a smoker to be short of breath.Cigarette smoke also contains tar which collects in the lungs. Tar contains many chemicals thatcause cancer which is why nine out of every ten people who die of lung cancer are smokers.

Exercise - Use the diagrams and information above to complete the sentences below.

1) Dirt and germs in the air you breathe are trapped by ____________________________________

2) Ciliated cells keep the lungs clean by wafting _________________________________________

_____________________________________________________________________________

3) Cigarette smoke stops the cilia from ______________________

4) A smoker may be short of breath because ____________________________________________

_____________________________________________________________________________

5) Tar from cigarette smoke causes ____________________________


W.S.19. Respiration. Name ………………………………….

All living organisms need to produce energy in the body. Energy is needed for many importantchemical reactions in the cells. We also need energy for movement, producing heat and to keep allof the parts working properly. We obtain our energy by reacting food and oxygen together in ourcells. This chemical reaction is called RESPIRATION. The main food substance that is used as thefuel for respiration is GLUCOSE which is gradually broken down into carbon dioxide and water.Energy is gradually released as this happens. This process can be shown with a word equation.

FOOD + OXYGEN CARBON DIOXIDE + WATER + ENERGY

The equation for respiration is the same as the one for burning food in air. The two processes aresimilar but respiration releases the energy much more slowly inside our cells.

Exercise 1 - Complete the missing labels on the diagram below.

Food Energy

Exercise 2 - Complete the sentences below.

1) The purpose of respiration is to produce ________________ in the cells.

2) The main food substance that is used in respiration is _____________________

3) Two uses of energy in the body are ______________________ and ______________________

4) A similar process to respiration is __________________ but this occurs much more quickly.

5) The waste gas produced by respiration is _____________________________

6) We get rid of carbon dioxide by __________________________________________________

7) The reason why all of the oxygen in the air does not eventually get used up in respiration is

because ______________________________________________________________________


Type of drug How it affects the body

Alcohol

Alcohol slows down the speed at which the brain and nervous system works.A little alcohol makes people feel happy and relaxed. More alcohol makes aperson feel dizzy and affects their judgement. Large amounts may make aperson unconscious and they may even die. An alcoholic is a person who isaddicted to alcohol. Heavy drinking over several years causes damage to thebrain, liver, and heart.

Tobacco

Tobacco smoke is very poisonous. A person can become addicted to smokingbecause of a chemical called nicotine contained in the smoke. Smokingcauses cancers, heart disease, bronchitis, and damaged lungs. Smoking alsomakes a person short of breath and more tense.

Cannabis

Cannabis or ‘pot’ causes hallucinations. This is when a person thinks thatthey are seeing or hearing something that does not exist. As a result they canbecome confused and do dangerous things and may have a fatal accident.

Solvents

Some people like to breathe in the fumes from substances such as glue andpaint (glue sniffing). This makes them feel dizzy and they may havehallucinations. The fumes get into the blood and damage the heart. Manypeople have died as a result of breathing in solvents.

W.S.20. Drugs and health. Name ………………………………….

Drugs are chemicals that affect the way the body works. Some drugs affect the brain. Some drugsare used by doctors to treat sick people. These can be very useful but they must be taken in thecorrect amounts. If a person uses drugs wrongly (drug abuse) it can be very harmful and may evenlead to death. It is illegal (against the law) to take certain drugs because they are so dangerous tohealth, however even legal drugs such as alcohol can be very harmful if they are taken in excess.Some drugs are ADDICTIVE. This means that a person can become dependent on them and if theydo not have the drug they may develop WITHDRAWAL SYMPTOMS such as shaking andsickness. The table below gives information about the effects of various drugs on health.

Exercise – Fill in the missing words in the passage below. Choose from the list of words at the bottom.

Drugs change the way the ......................... works. Many drugs are ......................... and are used bydoctors. Drug ........................ means using drugs wrongly. It is ......................... to take certain drugsbecause they are so dangerous. Legal drugs such as ......................... can also be very harmful ifthey are taken in large amounts. An ......................... is a person who has become dependent on acertain drug . It is very dangerous to drink alcohol and then drive because the ........................ areslowed down. An ........................ is a person addicted to alcohol. They may damage their brain,..................... and heart. People who smoke are usually more tense and ......................... as a result ofthe nicotine in their blood. The risk of developing ........................ cancer is much greater insmokers. Drugs such as cannabis make a person ......................... This can make them behave......................... The fumes from ......................... may damage the heart and even cause death.

illegal useful abuse alcohol hallucinate addict reactions liver lungnervous dangerously solvents body alcoholic


W.S.21. Germs and health. Name ………………………………….

Germs are MICROBES (microscopic organisms) that can live inside our bodies. The two maintypes of germ are BACTERIA and VIRUSES. Most types of bacteria are not germs and feed ondead material in nature, but the ones that invade our bodies cause us harm. They do this either byattacking our body cells or by producing waste chemicals called TOXINS that poison the body.Viruses are much smaller than bacteria and they can only exist inside living cells. A virus injects itsDNA (instructions) into a cell. The virus DNA tells the cell to make more viruses. Eventually thecell bursts open to release the new viruses.

A typical bacterium

Some have hairsfor movement

Some have aslimy coating

simple nucleus

cell wall

cell membrane

cytoplasm

Types of bacteria

COCCI (round)e.g. cause sore throat.

BACILLI (rod)e.g. cause typhoid.

A typical virus

outer coat

DNA (instructions) is injectedinto the cell it is attacking.

Feet attach to a cell

Exercise – Use the information and diagrams above to help you to complete the sentences below.

1) Germs are microbes that live ____________________________________

2) Bacteria and viruses can only be seen ___________________________________

3) Bacteria cause disease by attacking body cells or ______________________________________

4) Viruses are much _____________________ than bacteria.

5) Viruses can only live and multiply inside __________________________


Lymphocyte

W.S.22. Fighting germs. Name ………………………………….

There are huge numbers of microbes in the air, soil and water. Most of these microbes are harmlessbut some are germs and can do us harm. Therefore our bodies need a natural defence system. Theskin forms a barrier to stop germs entering the body. The breathing system is lined with a stickyliquid called mucus which traps the dirt and germs that we breathe in. Tiny hairs called CILIAgradually waft the dirty mucus up to the throat where it is swallowed. The germs are then killed byhydrochloric acid in the stomach. Germs sometimes get into the bloodstream through wounds. Ifthis happens white blood cells attack the germs. The diagrams below show how they do this.

Phagocyte

Bacteria are takenin and digested.nucleus nucleus

The lymphocte detects thebacteria and sends out chemicalscalled ANTIBODIES to destroythem.

Immunisation and medicines.

You can become immune to a disease without ever having the illness. This is done by injecting youwith a VACCINE. This contains either dead germs or a harmless form of the germ. The vaccinedoes not make us ill but it allows antibodies to build up in the body. If we ever come into contactwith the germ in the future we are ready to fight it off. This process is called IMMUNISATION.We are immunised against several diseases when we are children, e.g. polio, rubella and T.B.

If we do become ill we can be given medicines to help us fight the germs. Medicines often containANTIBIOTICS. These are chemicals that kill bacteria.


Most microbes are ......................... but some are germs that can live inside our bodies. The bodyneeds to ......................... itself from invading germs. The ......................... forms a barrier that stopsgerms getting into the body. Any germs that are ......................... in are trapped by sticky mucus inthe nose, ......................... and lungs. Eventually dirty mucus is ......................... and the hydrochloricacid inside the .......................... destroys the germs. The two types of white blood cell that killgerms are ......................... and lymphocytes. Phagocytes ......................... germs and lymphocytesmake .........................A ......................... contains dead or harmless germs. It allows antibodies to build up in the body.......................... can also be used to help us fight germs.

defend phagocytes medicines harmless skin antibodies eat breathedtrachea vaccine stomach swallowed


The balance between photosynthesis and respiration.

W.S.23. Photosynthesis. Name ………………………………….

Plants differ from animals in the way that they obtain their food. Animals feed on plants or otheranimals. Most plants can make their own food by using light energy and simple chemicals in aprocess called PHOTOSYNTHESIS. Water and carbon dioxide molecules are joined together tomake GLUCOSE sugar and waste oxygen gas. This process takes place in the leaf cells inside tinydiscs called CHLOROPLASTS. The chloroplasts contain a green chemical calledCHLOROPHYLL which absorbs the light energy needed for photosynthesis to happen. Thediagram below summarises the whole process.

sunlightcarbon dioxide

water

glucose

oxygen

The glucose sugar that is made may be changed into other useful chemicals for growth or storage.The plant also uses glucose as a fuel in RESPIRATION to release energy when it is needed in thecells. Animals also carry out respiration which is the opposite process of photosynthesis.

FOOD + OXYGEN CARBON DIOXIDE + WATER + ENERGY

The light energy that the leaves absorb during photosynthesis is stored as chemical energy in theglucose and then it is released during respiration.

Exercise - Use the information and diagram above to help you complete the sentences below.

1) Animals can not make their own ______________

2) _______________ is the form of energy used in photosynthesis.

3) The raw materials needed for photosynthesis are ______________________ and ____________

4) The green chemical that absorbs light energy in photosynthesis is called ___________________

5) _____________________ is the opposite reaction to photosynthesis.

6) Plants provide animals with food and _________________


Element Why it is needed

Nitrogen To make proteins for good general growth.

Magnesium To make the green chemical CHLOROPHYLL needed in photosynthesis.

Phosphorus For good root growth.

root hairA single root hair cellRoot tip

W.S.24. Plant nutrition. Name ………………………………….

Plants are able to make glucose sugar from carbon dioxide and water molecules by the process ofphotosynthesis. For healthy growth they also need to absorb nutrients called mineral salts from thesoil. Mineral salts are simple chemicals that are dissolved in the soil water. They contain essentialelements such as nitrogen, phosphorus and magnesium. Water and mineral salts are absorbed fromthe soil by the ROOT HAIR CELLS which cover the surface of the root. These cells are drawn outinto long hair-like structures which greatly increase the surface area for water absorption. Thediagram below shows what the surface of a root looks like.

vacuole

cell wall soil particleRoot hair absorbing water andminerals. Arrows show directionof water movement.

The table below shows some of the main elements needed by plants. Study it carefully and then tryto complete the exercise at the bottom of this page.

Exercise - Complete the missing words in the passage below. Choose from the list of words at the bottom.

Certain chemical ......................... are needed for healthy growth in plants. They are obtained frommineral salts ......................... in the soil water. Root ........................ cells absorb water and mineralsalts which are then transported up the ......................... to the leaves. The root hair cells greatly......................... the surface area of the root for water absorption. If a plant does not have enough......................... it cannot make chlorophyll and its leaves turn yellow. If a plant does not haveenough ......................... it cannot make enough proteins and its growth is stunted. Phosphorus isneeded for good ......................... growth.

root elements hair magnesium nitrogen dissolved stem increase


pine

W.S.25. Classification. Name ………………………………….

All of the millions of species (types) of living organisms can be sorted into groups. This process iscalled CLASSIFICATION. They are first sorted into very large groups that only have a fewfeatures in common. They are then sorted into smaller and smaller groups of organisms with morefeatures in common i.e. that are more closely related to each other.

Plants without flowers.spores beingreleased fromspore head.

horsetail

cone

MOSSES AND LIVERWORTSThey have small, simple roots andleaves. They can only grow in dampplaces. They reproduce with spores.

CONIFERSThey are trees with tough, needle-shapedleaves. They do not have flowers andreproduce with cones.

FERNS AND HORSETAILSThey have well developed roots andstems. They usually grow in damp,shady places. They reproduce withspores.

mushroom pin mould

spirogyra seaweed

moss liverwort

FUNGIThey do not contain the green chemicalchlorophyll and so do not make theirown food. Most feed on dead materialand reproduce with microscopic spores.

fern

needle

ALGAEThey live in water and have no roots orleaves. They carry out photosynthesisand can be green, brown or red.


There are ……………….. of species of living organisms on Earth. Classification means sortingthese into ……………….. The two largest groups of living organisms are ……………….. andanimals. The plant kingdom is divided into smaller groups depending on how they are……………….. to each other. Fungi are unusual plants because they do not contain green……………….. Therefore fungi do not produce their own ……………….. Algae have no……………………. or leaves. Fungi, mosses and ferns produce microscopic ……………….. forreproduction and conifers produce ………………..

spores groups millions related chlorophyll plants roots food cones


W.S.26. Flowering plants. Name ………………………………….

Flowers contain sex organs which produce seeds for reproduction. The male sex cells are inside thepollen grains. The female sex cells are called OVULES. Pollen grains are carried from one flowerto another by insects or wind. This is called POLLINATION. The sex cells then join together. Thisis called FERTILISATION. The fertilised ovules develop into seeds.

buttercup – insect pollinated. grass flowers – wind pollinated.

The flowers are light andfeathery to catch thebreeze.

The flowers are colourfuland scented to attractinsects.

Seed dispersal.

When the flower dies the seeds are left inside a FRUIT. Fruits help to DISPERSE (spread out) theseeds. Three types of fruit are shown below.

Sycamore seeds have wings.They are dispersed by wind.

Burdock seeds have hooksthat catch onto animals fur.

Blackberries are juicy but theseeds do not digest.

Exercise - Fill in the missing words in the passage below.

Flowers make ...................... so that plants can reproduce. The male sex cells are inside the...................... grains. The ...................... sex cells are called ovules. Pollination is when...................... is carried from one flower to another. Pollen can be carried by wind or......................... The insects visit the flower to drink the ......................... Flowers arecolourful and ......................... to attract insects. Plants that use wind to pollinate theirflowers are not brightly ......................... They are light and feathery to catch the breeze.

Fertilisation is when the male and female sex cells ...................... The fertilised...................... then develop into seeds. When the flower dies a ...................... is left behind.Fruits help to .......................... the seeds.

insects join pollen female seeds ovules scented coloured nectarfruit pollen disperse


W.S.27. Animals without backbones (1). Name ………………………………

All animals can be sorted into two main groups. VERTEBRATES are animals that have a backboneand an internal skeleton. INVERTEBRATES do not have a backbone or an internal skeleton. Readthe information below about the groups of invertebrates with soft bodies.

sea urchin

squidsnail

leech

JELLYFISH AND ANEMONESThey all live in water, usually in thesea. They have a very simple body withtentacles. Some have sting cells.

FLATWORMSThey have a long, flat body. Some livein freshwater. Some are parasites thatlive inside other animals.

SEGMENTED WORMSThey have a long body divided byrings into segments. Most of them livein water or soil.

MOLLUSCSThey often have a shell for protection.Most of them live in water. Somehave tentacles.

STARFISH AND SEA URCHINSThey all live in the sea. They have athick skin which is sometimes coveredin spines.

jellyfish sea anemone

flatworm tapeworm

earthworm

starfish

Exercise – Complete the sentences below.

1) Animals with a backbone are called _________________

2) Animals without a backbone are called __________________

3) Jellyfish and sea anemones both have _________________

4) A _______________ is a flatworm that lives inside other animals.

5) An earthworm’s body is divided into _________________

6) A ______________ is a mollusc that has a shell for protection.

7) Sea urchins are covered in _______________


W.S.28. Animals without backbones (2). Name ………………………………

ARTHROPODS are invertebrates with a hard outer coating. They all have a segmented body withjointed legs. This is a very large group and it can be divided into the smaller groups shown below.

millipedecentipede

shrimp

scorpionspider

waspbeetle

INSECTSThey have three parts to the body and sixlegs. The adults usually have four wingsand a pair of antennae.

SPIDERS AND SCORPIONSThey have two parts to the body andeight legs. Spiders usually spin a web ofsilk and have poisonous fangs. Scorpionshave a sting at the end of their tails.

CRUSTACEANSMost of them live in water. They usuallyhave a thick, hard coating. They havemany legs and two pairs of antennae.

CENTIPEDES AND MILLIPEDESThey have long bodies made up of manysegments. Centipedes have one pair oflegs on each segment and millipedeshave two.

crab


1) __________________ all have a hard outer coating.

2) A fly is an ______________

3) Insects usually have _______ legs and _______ wings.

4) Spiders have _______ legs.

5) Scorpions have a ___________ at the end of their tails.

6) Most __________________ live in water.

7) Crabs and _____________ are closely related.

8) The bodies of centipedes are made up of many _________________


W.S.29. Animals with backbones. Name ………………………………….

All VERTEBRATES have a backbone and an internal skeleton. Study the information below aboutthe five groups of vertebrate then try to complete the exercise at the bottom of this page.

FISHThey live in water and have gills forbreathing. They are covered with scalesand have fins for swimming.

AMPHIBIANSThe tadpole (young) lives in water andhas gills for breathing. The adult lives onland and has lungs. They have a moistskin without scales.

REPTILESThey have a dry, scaly, waterproof skin.Their eggs have a tough leathery shelland are laid on land.

BIRDSThey are covered with feathers and havewings for flying. Their eggs have a hardshell. They have a beak for feeding.Their bodies are constantly warmbecause they generate heat from inside.

MAMMALSThey have hair and a constantly warmbody. The young develop to an advancedstage inside the mother’s body. Afterthey are born the young are fed on milkfrom the mother’s body. Humansbelong to this group.

shark stickleback

newt

snake

blue tit sparrowhawk

wolf horse

frog

lizard


All vertebrates have an ……………….. skeleton. All ……………….. live in water and have gillsfor breathing. Both fish and ……………….. have a scaly skin. The young of ……………….. livein water but the adults live on land. Amphibians have a ………………..skin. Both reptiles and……………….. lay eggs on land. Birds are covered with ……………….. and have ……………….for flying. Both birds and ……………….. have a constant warm body temperature. Mammals have……………….. and feed their young on ………………..

amphibians fish reptiles birds hair internal milk wings moist feathers mammals


W.S.30. Variation. Name ………………………………….

All animals and plants are different from each other. Even members of the same species (type)show small differences and no two humans are exactly alike. This variety in all living organisms iscalled VARIATION. Some features that vary which are easy to study in humans are height, mass,hair colour, eye colour and shoe size. CONTINUOUS VARIATION is when a feature shows manydifferent types eg. height. DISCONTINUOUS VARIATION is when a feature only shows a fewdifferent types eg. human blood groups and whether a person can roll their tongue or not.Variation is caused partly by different GENES (instructions) that individuals inherit from theirparents and partly by different ENVIRONMENTS (surroundings) that individuals live in.

The two causes of variation in living organisms.

Genetic (inherited) Environment (surroundings)

Chromosomes are microscopic threads inside the nucleusof every cell. They hold the GENES that control aperson’s features and how they develop. All sperms andova contain a different set of genes therefore every personreceives a different combination from their parents.

23 chromosomes in each nucleus.

ovumsperm

FOOD SUPPLY affects the growth rateof young animals. Two identical twinshave the same genes but one may beheavier than the other due to eating morefood. Plants also grow better in soil thathas a good water and mineral supply.

CLIMATE affects how animals andplants develop. Some animals grow athicker coat if their environment becomescolder. Plants usually grow faster in thesun than they do in the shade. A person’sskin may become darker (tanned) if theyare exposed to more sunlight.

Exercise - Use the information above to help you complete the sentences below.

1) All living organisms are different from each other. This is called ______________________

2) The two types of variation are ________________________ and _______________________

3) An example of continuous variation in humans is __________________________

4) We are all different partly because of the ______________ we inherited from our parents and

partly because of the ___________________ that we live in.

5) Every sperm and ______________ contains a different set of genes.

6) Food supply affects the ______________ rate of young animals.

7) Plants will grow larger in soil that is rich in _________________


smallest dogsbred together.

tallest dogsbred together.

W.S.31. Selective breeding. Name ………………………………….

Humans have gradually changed wild species of plants and animals by SELECTIVE BREEDING.This means picking out plants or animals that best show the features that humans like. Theseindividuals are then bred together so that they pass on their good qualities to the next generation. Bycontinuing this process over many generations small differences add up into larger ones untileventually the plant or animal may look quite different to its wild ancestor. Dogs, cats, pigeons,rabbits, goldfish, farm animals and crops have all been produced by this process. The diagrambelow shows how some of the modern breeds of dog have been developed from their wild, wolf-like ancestor.

wolf-like ancestor

wolfhound greyhound toy breeds

fastest dogsbred together.

Natural selection.

Most scientists believe that in nature plants and animals have gradually changed over millions ofyears from very simple forms into the types we see today. This process is called EVOLUTION. Theindividuals that are the best adapted to their environments (surroundings) have a better chance ofsurviving and passing on their features. Therefore nature is selecting which individuals survive andbreed. This idea is called NATURAL SELECTION.


Wild species of plants and animals have gradually been ……………….. by selective breeding. Theplants or animals that show the best ……………….. are picked out and allowed to breed. By doingthis over many generations humans have produced more ……………….. plants and animals. Dogs,cats and ……………….. have all been produced by this process. The racing pigeon has beendeveloped from a wild ……………….. Only the ……………….. birds were allowed to breed overmany ……………….. until the present day bird was produced. Most scientists believe that in……………….. plants and animals have been gradually changing over millions of years. The best……………….. individuals are more likely to survive and pass on their good features to the nextgeneration.

ancestor nature features fastest useful pigeons adapted changed generations


Environmental condition Why it is important for survival

TemperatureThis affects the chemical reactions inside the cells ofliving organisms. When it is cold the chemical reactionsslow down and organisms become sluggish.

LightPlants need light in order to make food by photosynthesis.Animals need the food that plants make.

WaterMost of an organism’s body is made up of water. It isneeded in order to dissolve chemicals for transport and sothat chemical reactions can take place.

Oxygen

This is needed so that energy can be released inside thecells by the process of respiration. There is usually plentyof oxygen in the air but it may be in short supply in water,soil or mud.

W.S.32. Living organisms and their habitats. Name ……………………………

Plants and animals can only live in certain places. The place where a plant or animal is normallyfound is called its HABITAT. All species have special features called ADAPTATIONS which helpthem to survive in their habitats. For example a polar bear has a thick coat of fur to protect it fromthe cold and a camel can store large amounts of water in its stomach. Different organisms are foundin different places because each species can only survive in the particular conditions that it isadapted to. The table below shows some of the ENVIRONMENTAL CONDITIONS that areimportant for the survival of organisms in their habitats.

Exercise 1 – Study the two lists below and then join up each organism with its correct habitat.

Organism Habitatfox oceandolphin junglemonkey woodlandstickleback meadowbuttercup pond

Exercise 2 – Complete the sentences below using the words at the bottom.

1) A ____________________ is the place where an organism lives.

2) An ____________________ is a special feature which helps an organism to survive.

3) An adaptation of a cactus is a thick, ____________________ outer covering.

4) The conditions that make up an organism’s surroundings are called its ____________________

5) ____________________ is needed for chemical reactions to take place inside cells.

environment adaptation water habitat waterproof


W.S.33. Adapting to changes in habitats. Name ……………………………

The conditions in a habitat are always changing from day to night and from one season to the next.Light and temperature increase after sunrise and usually reach a peak at midday. In dry deserts thedays are usually very hot but the nights are very cold. Lizards and snakes need to absorb heat fromtheir surroundings in order to keep their bodies working quickly. Study the diagrams below whichshow how a lizard behaves at different times of the day.

In the early morning the lizardbasks in the Sun to warm its bodyso that it can move more quickly.

Later in the morning thelizard becomes veryactive and hunts for food.

At midday the temperature in thedesert has become too high andthe lizard hides in the shade.

The lizard’s behaviour is an adaptation to help it to survive. Many desert animals areNOCTURNAL (only active at night) in order to avoid the heat of the day.Countries that are on or near the equator often have more or less the same climate all year round butas we move towards the poles the difference in the SEASONS becomes greater. Seasons aredifferent types of weather throughout the year. The British winter is very cold and there is littlefood available. Many animals grow a thicker fur coat to stop heat loss and save energy. Someanimals HIBERNATE through the winter. Hibernation is like a deep sleep. The body temperaturefalls and the heart and breathing almost stop. In this state the body needs very little energy and theanimal can use its stored fat reserves over the winter. Many birds MIGRATE during the winter months. This means that they fly to warmer countrieswhere they can find enough food and live more easily.

Exercise 1 – Use the information above to help you to write down the correct words beside their meanings.

Word Meaning

____________________ Only active at night.

____________________ Fly to a warmer country.

____________________ A deep sleep to save energy.

____________________ Different types of weather throughout the year.

Exercise 2 – Complete the missing words in the passage below.

The conditions in a habitat are constantly C ......................... from day to night. In a D .......................it may be very hot during the day but very cold at night. A lizard’s B ......................... helps it tosurvive in the desert. In winter it is very cold and there is not as much F ............... available foranimals. Many desert animals are N ......................... Some animals A ................. to cold winters bygrowing a thicker fur coat. Most animals store F ......... under the skin during autumn. Animalshibernate in order to save E ................ during winter. The body T ..............…....... falls and the bodyslows right down.


fox

W.S.34. Food chains and pyramids of numbers. Name ………………………

Green plants make glucose sugar from carbon dioxide and water molecules by the process ofPHOTOSYNTHESIS. For healthy growth they also need to absorb mineral salts from the soil.Animals can not make their own food in this way and must feed on plants or other animals. Thefood is passed along a FOOD CHAIN.

grass woodmouse

Food chains always begin with plants. Animals that only eat plants are called HERBIVORES andanimals that eat other animals are called CARNIVORES. Some animals eat both and are calledOMNIVORES. Carnivores are also called PREDATORS and the animals that they hunt are calledthe PREY. In most habitats there are more plants than herbivores and more herbivores thancarnivores. This can be shown with a PYRAMID OF NUMBERS, where the size of each boxrepresents the size of each population.

FOX

WOODMOUSE

GRASS

Pyramids of numbers are usually large at the bottom and small at the top, but sometimes they havea different shape because of the different sizes of the organisms in them. Two examples of this areshown below.

BLUE TITS

GREENFLY

ROSE BUSH

LIONS

ZEBRA

GRASS

FLEAS

A better way of showing how much food is present at each level in the food chain would be tomeasure the total mass of each population. This is called the BIOMASS of the population. Forexample even though there are many more greenflies than rose bushes they weigh a lot less.


In most habitats there is a mixture of ........................., herbivores and carnivores. Carnivores areanimals that eat other ......................... Herbivores eat plants and are ......................... upon bycarnivores. Another name for carnivores is ......................... and the animals that they hunt are calledthe ......................... The amount of plants in a habitat must be ......................... than the amount ofherbivores or else the herbivores would run out of ......................... In the same way there must be........................ carnivores than herbivores.

predators animals food fewer preyed plants prey greater


W.S.35. Food webs. Name ………………………………….

A plant or animal usually belongs to several food chains. For example, grass is eaten by deer aswell as rabbits, and rabbits are eaten by stoats as well as foxes. For this reason food chains can beconnected together to make FOOD WEBS. The diagram below shows a food web in a lake.

large fish grebe

water beetle small fish newt

tadpole water snail water louse

pondweed algae (tiny plants) dead tree leaves

Exercise – Arrange all of the organisms in the food web above under the three headings below.

PLANTS HERBIVORES CARNIVORES

……………….. ……………….. ………………..……………….. ……………….. ………………..……………….. ……………….. ………………..

………………..………………..

The predators of small fish are _____________________ and ____________________

The prey of small fish are __________________ __________________ and _________________

The animal that completely depends on dead tree leaves is the ____________________


W.S.36. Poisoned food chains. Name ………………………………….

Farmers often spray their crops with PESTICIDES in order to kill pests such as insects and weeds.If the pesticide does not break down easily it can stay in the environment (surroundings) a long timeand poison animals higher up the food chains. If it rains, pesticides can also be washed into streamsand ponds where they may cause serious pollution. The diagram below shows how pesticides canbuild up along food chains.

A farmer sprays his crop with pesticide.

One caterpillar eats many leavesand takes in the pesticide.

One small bird eatsmany caterpillars.

One hawkeats many

small birds.

If the pesticide is passed on from the caterpillars into small birds and then into the hawk we can seehow it would quickly become concentrated in the hawk’s body. Many pesticides such as DDT havenow been banned because they were poisoning predators and even humans as well as the pestspecies. Scientists are now developing less harmful pesticides that only affect the pest species andthat are BIODEGRADABLE (break down a short time after they have been used). They are alsotrying to find other ways of controlling pests by using their natural enemies. This is calledBIOLOGICAL CONTROL.

Exercise 1 – Use the information above to help you complete the sentences below.

1) ____________________ are poisons that kill pests.

2) Pesticides can get into food ______________ and poison other animals.

3) Pesticides can also __________________ streams and ponds.

4) _________________________________ means using a pest’s natural enemy to destroy it.

Exercise 2

Suppose that a hawk eats fifty small birds in a week and every small bird eats one hundredcaterpillars. If every caterpillar takes one unit of pesticide into its body, how many units will thehawk take in over one week?

Answer = _________________


W.S.37. Populations. Name ………………………………….

A population is a number of organisms of the same species (type) living in one place. For examplethere may be a population of one thousand tadpoles living in a pond, or a population of five hundredoak trees in a wood. There are a number of factors that control how big a population can grow. Thegraph below shows how a population of rabbits grew when scientists placed one hundred of themonto an island where rabbits had never lived before.

Number of rabbits

Time (years)

100

200

300

400

1 2 3 4 5 6 7

The graph shows that the population grew slowly at first as the rabbits were getting used to theirnew habitat and just beginning to breed. The population then grew very quickly as the rabbits hadplenty of food and space and were reproducing. The growth rate of the population then sloweddown until it reached a fairly steady level of about 260 rabbits. At this point competition betweenthe rabbits for food and space had increased and predators were finding and killing the rabbits moreeasily. When the balance between the number of births and deaths becomes equal the populationstops growing.There is always competition between living organisms for food and space. The best competitorshave a better chance of surviving and producing offspring. This idea is called ‘survival of thefittest’. In this case the strongest or fastest rabbits may have the best chance of surviving andpassing on their features to the next generation.

Exercise 1 – Complete the missing words in the passage below. Choose from the list of words at the bottom.

There are a number of factors that control how big a population of animals can …………………Competition for ………………… and space is important. As the population grows there will be………………… competition and so more animals will ………………… Predators are alsoimportant in controlling the numbers of ………………… animals. If the number of predatorsincreases more prey will be ………………… If the number of predators decreases more prey will………………… In the same way, the ………………… of a predator’s population is controlled bythe numbers of its prey. If there are more prey there will be more predators. The rabbits that are thebest ………………… for food and space are the most likely to survive and pass on their goodcharacteristics to the next generation.

size greater prey killed grow survive competitors food die


1) A ___________________ is a number of organisms of the same species living in one place.

2) The graph shows that it took ______ years for the rabbit population to reach it’s maximum size.

3) A population remains steady when the number of births equals the number of ______________


Property Solids Liquids GasesDensity (heavy or light) High density

(heavy)Low density(light)

How easy are they to compress(squash)?

Hard Easy

Do they flow? Yes Yes

Do they keep the same shape? No

Do they keep the same volume? Yes

W.S.38. Solids, liquids and gases. Name ………………………………….

Scientists believe that all matter or substance is made up of particles that are too small to see. Thethree states of matter are SOLID, LIQUID and GAS. They all have different properties due to thearrangement and movement of their particles. The diagrams below show a MODEL of how theparticles are thought to behave in solids, liquids and gases.

Solids.The particles are held tightly in position bystrong forces. They make small vibrations butthey stay in place. This explains how solids havea definite shape and volume. Solids are DENSE(heavy) and they cannot be compressed(squashed) easily because the particles arealready packed closely together.

Liquids.The particles can move past each other but theyare still held closely together by strong forces.A liquid can flow because the particles are notheld in a fixed position. Liquids are DENSEand they can not be compressed easily. A liquidcan change its shape but not its volume.

Gases.The particles are far apart and they movearound very quickly. There are only very weakforces between the particles which bounce offeach other and off the sides of any containerthat they are held in. Gases have a low density(they are very light) and they do not have adefinite shape or volume.

Exercise – Complete the spaces in the table below.


W.S.39. Changes of state. Name ………………………………….

When a solid is heated it usually changes into a liquid state and then a gas state. When a gas iscooled it usually changes back into a liquid and then into a solid. We can use the particle theory ofmatter to explain how these changes take place. The diagrams below explain this using water as anexample.

Solid – ice.The particles are heldfirmly in place but theyvibrate.

Liquid – water.The particles gain moreenergy and the vibrationsbecome stronger until theybreak apart and move around.

Gas – steam.The particles have nowgained enough energy tobreak free of the forces ofattraction. They are nowmoving very quickly.

heat heat

Gas pressure and diffusion.If a gas is squeezed into a small space e.g. whenair is pumped into a car tyre or a balloon, it exertsa PRESSURE. This is caused by the particlesbumping against the walls of the container as theyquickly move around.A gas will DIFFUSE (spread out) until it fills upany area that it is contained in. This happensbecause the particles are moving RANDOMLYand very quickly. Eventually gas particles diffuseuntil they are EVENLY SPREAD OUT.

Air particles movearound quickly andbump against theinside of theballoon.

Exercise – Join up the words in the left-hand column with their meanings in the right-hand column.

DIFFUSION A solid changing to a liquid.

ICE The spreading out of particles.

MELTING The solid state of water.

STATE OF MATTER A solid, liquid or gas.

EVAPORATION A gas changing to a liquid.

CONDENSING A liquid changing to a gas.


one electron

hydrogen atom

W.S.40. Elements. Name ………………………………….

An element is a pure substance that cannot be broken down into anything simpler. Everything onEarth is made from about one hundred different elements. Scientists believe that elements are madeup of vast numbers of tiny particles called ATOMS. Each element contains only one type of atom.For example gold atoms are different to oxygen or iron atoms.

Atoms.

An atom is the smallest particle of an element. They are much too small to be seen even with themost powerful microscope. Atoms consist of a NUCLEUS in the centre with ELECTRONS movingaround it. The diagrams below show the structure of a hydrogen and carbon atom.

carbon atom

The nucleusconsists ofone proton.

The outer shell containsfour electrons.

The inner shell containstwo electrons.

The nucleus consistsof six protons andsix neutrons.

= positively charged proton

= neutron (no charge)

= negatively charged electron

Atoms always have the same numberof electrons and protons so that theiroverall charge is neutral (no charge).

All of the elements are different because they have different numbers of protons in their atoms. TheATOMIC NUMBER is the number of protons that an atom contains. The smallest atom is hydrogenwith an atomic number of one. Lead is one of the largest atoms with an atomic number of eightytwo.

Exercise – Complete the missing words in the sentences below.

1) An _______________ cannot be broken down into anything simpler.

2) The smallest particle of an element is called an _______________

3) The _______________ is in the centre of an atom.

4) Electrons have a ________________ charge and protons have a ________________ charge.

5) The atomic number is the number of ________________ in an atom.

6) ________________ is the smallest atom.


Element Symbolhydrogen Hcarbon Cnitrogen Noxygen Oiron Felead Pbmagnesium Mgchlorine Clsulphur Saluminium Al

W.S.41. The periodic table. Name ………………………………….

Every element has been given a name and itsown SYMBOL. Some symbols are easy toremember, but some are more difficultbecause they are taken from the Latin name.For example Na is the symbol for sodiumbecause it is taken from its Latin name whichis Natrium. The table opposite shows some ofthe most common elements with theirsymbols.

All of the elements have been arranged into the PERIODIC TABLE. This contains seven rows ofelements called PERIODS. These are arranged so that each column contains elements with similarproperties. The table shows the symbol and ATOMIC NUMBER (number of protons) for everyelement.

2

3

4

5

6

7

PeriodGroup

1

GroupO

I II H1

III IV V VI VII He2

Li3

Be4

B5

C6

N7

O8

F9

Ne10

Na11

Mg12

Al13

Si14

P15

S16

Cl17

Ar18

K19

Ca20

Sc21

Ti22

Fe26

Co27

Ni28

Cu29

Zn30

Ga31

Ge32

As33

Se34

Br35

Kr36

Rb37

Sr38

Y39

Zr40

Nb41

Mo42

Tc43

Ru44

Rh45

Pd46

Ag47

Cd48

In49

Sn50

Sb51

Te52

I53

Xe54

Cs55

Ba56

La57

Hf72

Ta73

W74

Re75

Os76

Ir77

Pt78

Au79

Hg80

Tl81

Pb82

Bi83

Po84

At85

Rn86

Fr87

Ra88

Ac89

magnetic metals

transition metals

V23

Cr24

Mn25

The mostreactive metals.

The HALOGENS arethe most reactivenon-metals.

The NOBLEGASES arevery unreactive.

This line dividesthe metals fromthe non-metals.

Ce58

Pr59

Nd60

Pm61

Sm62

Eu63

Gd64

Tb65

Dy66

Ho67

Er68

Tm69

Yb70

Lu71

Th90

Pa91

U92

Np93

Pu94

Am95

Cm96

Bk97

Cf98

Es99

Fm100

Md101

No102

Lr103

Exercise – Use the periodic table to help you complete the missing words in the passage below.

Each group in the periodic table contains elements that have similar …………………… The atomicnumber gives the number of ………………… that an element contains. The lightest element is………………… (H) which has an atomic number of one. The atomic number of …………………is eight. Sodium (Na) and potassium (K) are two very ………………… metals. Iron (Fe) and nickel(Ni) are two of the ……………………. metals. The most reactive non-metals are called the………………… The ……………… gases are very unreactive. Magnesium (Mg) and calcium (Ca)are both in group ………………… of the table.


W.S.42. Compounds. Name ………………………………….

Elements sometimes join together by chemical reactions to form compounds. Compounds are newsubstances that have different properties to the elements that formed them. We can tell if a chemicalreaction has happened because new substances are formed and energy is either taken in or given outduring the process. It is also usually difficult to reverse the process.

Exercise 1 – Study the chemical reactions below and then try to fill in the missing words or symbols for each one.

Making salt

Coal burning

CARBON + OXYGEN CARBON DIOXIDE + HEAT

…… + O2 CO2 + HEAT

Hydrogen exploding

balloon

lightedsplint HYDROGEN + ……………….. WATER + HEAT

2H2 + O2 2H2O + HEAT

gas jar

burning spoon SODIUM + CHLORINE SODIUM CHLORIDE (salt)

Na + Cl ……….burning sodium

chlorine gas

Exercise 2 – For each of the changes below write down whether it is a physical or chemical change.

When a firework explodes it is a ____________________ change.

When salt dissolves in water it is a ____________________ change.

When a cake is baked in an oven it is a ____________________ change.

When ice melts it is a ____________________ change.


W.S.43. Separating mixtures. Name ………………………………….

Mixtures contain a number of substances that are not chemically joined to each other. If the correctmethod is used they can be separated back into their constituents (parts). The diagrams below showdifferent methods of separating mixtures. Study these carefully and then fill in the missing words inthe paragraphs.

Filtration.This method separates small, solidparticles from liquids. In thediagram a mixture of sand andwater is being filtered. The........................ passes through thefilter paper and the ...................... isheld back. The sand particles aretoo large to pass through the poresin the ......................

Distillation.This method separates dissolvedchemicals (SOLUTES) from theliquids that they are dissolved in(SOLVENTS). In the diagram saltsolution is being separated into saltand ........................ The water.......................... from the boilingsolution and then condenses as it iscooled in the condenser. The salt isleft behind in the .........................

Chromatography.This method separates two or morechemicals that are dissolved in thesame solvent. In the diagram thecolours in pen ink are beingseparated. As water rises up the......................... it takes the colourswith it. Different colours travel atdifferent ........................ If the inkcontains more than one colour theywill separate out along the paper.

sand + water

filter paper

funnel

sand

water – theFILTRATE

thermometer

warm water out

cold water in

salt solution

HEAT

Leibig condenser

distilled water

glass rod

paper clip

filter paper

ink spot

flask

water

Exercise – Study the two lists below and then join up each mixture with the correct method for separating it.

Mixture Separating method

muddy water distillationcopper sulphate solution filtrationpeas and sand magnetic attractioniron filings and sawdust sieving


Metals Non-metals

Most are shiny solids at room temperaturealthough mercury is a liquid. They usuallyhave high melting points.

Good thermal (heat) conductors.

Good electrical conductors.

A few are magnetic (iron, cobalt and nickel).

They are often flexible (bendy) and can behammered into shape (malleable).

They vary widely in their physical properties.They usually have low melting points andmany are gases at room temperature.

Most are poor thermal conductors.

Poor electrical conductors apart from graphitewhich is a form of carbon.

None are magnetic.

They are often brittle (hard but break easily).

W.S.44. Metals and non-metals. Name ………………………………….

All of the elements can be divided into two main groups which are METALS and NON-METALS.The table below shows the properties of each group.

Exercise 1 – Study the diagrams of elements below and then write down whether each one is a metal or non-metal.

iron nail

magnet

Iron is a …………………….

lid

gas jar

Bromine liquid easilychanges into a gas anddiffuses upwards.

Bromine is a …………………….

The bulblights up

cell cell

The bulb doesnot light.

crocodile clip

copper coin sulphur Sulphur is a brittle,yellow solid.

Copper is a ……………………. Sulphur is a …………………….


1) ______________ is the only metal that is a liquid at room temperature.

2) _______________ is the only non-metal that is a good conductor of electricity.

3) The ________________ metals are iron, cobalt and nickel.

4) The word ______________________ means a material can be hammered into shape.


Substance Melting point (°C) Boiling point (°C)

Oxygen

Ethanol

Water

Sulphur

Iron

-219

-15

0

119

1,540

-183

78

100

445

2,900

Heat and it EVAPORATESHeat and it MELTS

W.S.45. Changes of state. Name ………………………………….

The three states of matter are SOLID, LIQUID and GAS. When one state changes into another, e.g.if solid water (ice) melts to form liquid water, we say that a CHANGE OF STATE has taken place.This is summarised in the diagram below.

SOLID LIQUID GAS

Cool and it FREEZES Cool and it CONDENSES

When a solid changes to a liquid, or a liquid changes to a gas, heat is absorbed. This is because theparticles that make up the substance need more energy to move faster and overcome the forces thathold them together. When a gas changes to a liquid, or a liquid changes to a solid, heat is given out.This is because the particles lose energy as they slow down and become attracted to each other.However the substance still keeps the SAME MASS because it still contains the SAME NUMBEROF PARTICLES.

Exercise – Use the information in the table below to help you complete the sentences at the bottom of this page.

1) Oxygen is a __________ at room temperature.

2) Water and _________________ are liquids at room temperature.

3) __________________ and iron are solids at room temperature.

4) Sulphur melts at a temperature of _____________

5) The substance with the lowest melting point in the table is _________________

6) If water and ethanol were mixed together and then heated the _________________ wouldevaporate first.


W.S.46. Solubility. Name ………………………………….

The diagrams below show how sugar can be dissolved in water.

water – the SOLVENTThe sugar hasDISSOLVED inthe water to formsugar SOLUTION.

stirstirring rod

sugar – the SOLUTE


If a solid substance ……………………. in water we say that the substance is SOLUBLE. Thesubstance that dissolves is called the SOLUTE and the liquid that it dissolves in is called theSOLVENT. Water is a good ……………………. because many substances will dissolve in it. Nailvarnish will not dissolve in water but it is soluble in a chemical called propanone which is used tomake nail varnish ……………………. If you have been using ……………………. paint you cannot wash your brush in water because the paint will not dissolve. The correct solvent for gloss paintis white ……………………. Therefore ……………………. have different solubilities in differentsolvents.

spirit solvent solutes remover dissolves gloss

The effect of temperature on solubility.

The cold water isfully SATURATEDwith sugar when nomore will dissolve.

The excess sugar nowdissolves because it ismore soluble in hotwater.

heat

Keep adding sugar.

Exercise 2 – Use the information in the diagrams above to help you complete the sentences below.

1) If you keep adding sugar to cold water you reach a point where no more sugar will ___________

2) A solution that will not dissolve any more solute is said to be fully ___________________

3) Solids are ______________ soluble in water as the temperature rises.

4) Gases are ______________ soluble in water as the temperature rises.


W.S.47. Expansion. Name ………………………………….

If a metal bar is heated up it EXPANDS (gets bigger) by a tiny amount. This happens because theparticles that make up the bar gain more energy and so vibrate more.

HEAT The particles vibratemore and so theymove further apart.

Most materials expand slightly when they are heated.

Overhead wires shorten in cold weather andcould snap.

Problems caused by expansion. Uses of expansion.

In hot weather a bridge could expand and buckle.

Gaps are leftfor expansion.

roller

As the mercurywarms up it expandsand moves up thethermometer scale.

mercury

Slack is leftin the wires.

Rivets hold metal plates tightly together.

Very hot rivet ishammered flat.

It cools downand contracts topull tightly.


Most materials ……………………. when they are heated and ……………………. when they arecooled. This is because their particles ……………………. more when hot and so move further……………………. In hot weather a metal bridge could expand and ……………………. Toprevent this from happening it is held on rollers. Overhead wires could contract and ……………….in cold weather. To prevent this from happening they are given slack when they are put up. Mercuryis a liquid metal that is used inside a ……………………. When it is put in a warmer place themercury expands and moves up the …………………….

vibrate apart snap thermometer contract buckle expand scale


W.S.48. Rocks and weathering. Name ………………………………….

Although we think of rocks as being extremely hard materials their surfaces can be graduallybroken up when they are exposed to the weather. This process is called WEATHERING. Thediagrams below show the various ways in which rocks are weathered.

Rainwater is naturally slightlyacidic due to dissolved carbondioxide. This causes certain rocks,e.g. limestone to gradually dissolveaway.

Rain.

Wind carries sand particleswhich blast against the surfaceof rocks and produce more sand.

Wind.

Expansion and contraction.DAY NIGHTHeat is absorbed.

In a desert it is very hot during the day and very cold at night.Constant expansion and contraction of rocks causes them to break up.

Rock expands. Rock contracts.

Heat is lost.

Freezing of water.

Water fills a crackin the rock.

Ice forms whichexpands.

The rock is forcedapart and the crackgets bigger.


1) The gradual wearing away of rocks is called ____________________

2) In a wet climate the main way in which limestone rocks weather is by the action of __________

3) In deserts rocks can be weathered by _____________ carried in the wind.

4) Expansion and ____________________ can cause rocks to crumble.

5) When water _________________ it expands. This can produce large forces which can breakrocks apart.


sea

Layers of sedimentsform.

Small particles of rock (sediments)are TRANSPORTED by rivers.

volcanic eruptions

W.S.49. The rock cycle. Name ………………………………….

Over millions of years the Earth’s rocks are gradually changed from one type into another. Thisprocess is called the ROCK CYCLE. The diagram below shows how it happens. Study thiscarefully and then try to complete the exercise underneath.

Igneous rock

Metamorphic rock

Movement of plates causesheat and pressure.

Sedimentary rock

melting

molten rock (magma)

cooling

WEATHERING


Weathering of rock surfaces causes small particles called ……………………. to form. Thesediments are …………………….. by rivers to seas. Over many years ……………………. ofsediments build up on the sea bed. As these layers are buried deeper they are gradually……………………. into sedimentary rocks. Sandstone and ……………………. are two examplesof sedimentary rocks. Heat and pressure deep inside the Earth may change sedimentary rock into……………………. rock. Eventually rocks inside the Earth may melt to form …………………….Sometimes magma returns to the surface during volcanic ……………………. It then cools down toform solid ……………………. rock.

compressed mudstone magma igneous sediments metamorphic transportederuptions layers


shells of tinysea creatures

W.S.50. Types of rock. Name ………………………………….

All of the different rocks that exist in the Earth’s crust can be divided into three main typesdepending on how they were formed. The texture (feel) of a rock and the minerals that it containsdepend on the processes that formed it. Study the information below about the three types of rock.

Igneous rocks.These are formed when molten magmacools down and becomes solid. They aremade of tiny crystals. If the magma coolsquickly on the surface of the Earth thenthe crystals are small. If the magma coolsslowly, deeper in the Earth’s crust, thenthe crystals are larger. Igneous rocks arevery hard.

Sedimentary rocks.These are made from layers ofSEDIMENT (small particles) on thebottom of rivers or seas. The sedimentsare compressed as more layers build upon top of them. Eventually the particlesbecome cemented together to form solidrocks. The layers of rock are calledSTRATA. Sedimentary rocks have agrainy structure and they easily crumble.

Metamorphic (changed) rocks.These are formed from igneous orsedimentary rocks when they are exposedto heat or pressure deep underground.They are usually harder than the rocksthat formed them.

large crystals

granite basalt

very small crystals

sandstone limestone

sand grains

limestone marble

heat + pressure


1) Igneous rocks are formed from ____________________________________________________

2) Granite contains very large crystals because the magma cooled ___________________________

3) Sedimentary rocks are made from __________________________________________________

4) Layers of rock are called ________________

5) Sedimentary rocks easily _____________________

6) Metamorphic rocks have been __________________ by heat or pressure.

7) Limestone changes into ________________ when it is exposed to heat and pressure.


W.S.51. Chemical reactions. Name ………………………………….

On Earth there are a huge number of different materials which make up everything around us.These have all been formed by chemical reactions from about one hundred simple elements. As anexample the diagram below shows a chemical reaction between the elements iron and sulphur.

magnet

Sulphur (S)32g

Iron filings (Fe)56g

Heat stronglyIron sulphide (FeS)

88g

A black solid thatis NOT magnetic.

This reaction can be shown as a word equation:

IRON + SULPHUR IRON SULPHIDE (REACTANTS) (PRODUCT)

The new substance formed is a compound called iron sulphide. It has different properties to the ironand sulphur that it is made from.

Exercise 1 – fill in the missing words in the sentences below.

1. The mass of the reactants (starting chemicals) is E _ _ _ _ to the mass of the products (thechemicals that are made).

2. The products have different P _ _ _ _ _ _ _ _ _ to the reactants.

3. During a chemical reaction H _ _ _ is either taken in or given out.

4. A chemical change is difficult to R _ _ _ _ _ _ (go backwards).

Exercise 2 – Join up each word in the left hand column with its correct meaning on the right.

ELEMENTS The chemicals that are made.

PRODUCTS The simplest substances.

COMPOUND Starting chemicals.

REACTANTS Elements joined together.


W.S.52. Types of chemical reaction. Name ………………………………….

There are several different types of chemical reaction. Study the information below and then try tocomplete the exercises at the bottom of this page.

SynthesisThis occurs when two or more substances join together to make a single new substance. Forexample the reaction between iron and sulphur when they are heated together :

heat IRON + SULPHUR IRON SULPHIDE

DecompositionThis occurs when a single substance breaks down into simpler substances. For example, if calciumcarbonate (limestone) is heated to a very high temperature it breaks down into calcium oxide(quicklime) and carbon dioxide gas :

heatCALCIUM CARBONATE CALCIUM OXIDE + CARBON DIOXIDE

OxidationThis occurs when a substance gains oxygen during a chemical reaction. The substance that gains theoxygen is OXIDISED. For example, when copper is heated in air it forms black copper oxide:

heat COPPER + OXYGEN COPPER OXIDE


1) Synthesis means when substances _ _ _ _ together.

2) Decomposition means when a substance _ _ _ _ _ _ down.

3) Oxidation is when a substance gains _ _ _ _ _ _ in a chemical reaction.

Exercise 2 – For each diagram below write down the type of chemical reaction it shows.

crystals

1) Burning sodium metalin chlorine gas to formsodium chloride (salt).This type of reaction is :

____________________

heat

Brown gasgiven off.

powder leftbehind

2) Heating white lead nitrate crystalsto produce a yellow powder and abrown gas. This type of reaction is :

_____________________________

3) If an iron nail is exposedto air it forms orange ironoxide (rust). This type ofreaction is :

______________________

chlorinegas


W.S.53. Burning. Name ………………………………….

Burning is a type of oxidation reaction. It happens when a substance reacts with oxygen in the air toproduce heat and light. The substance that burns is oxidised during the reaction. For example whencarbon in the form of coke is burnt the carbon is oxidised to form carbon dioxide gas :

CARBON + OXYGEN CARBON DIOXIDE + heat and light.

Most FUELS are compounds of carbon and hydrogen. They can be burnt to release useful energy.When they burn carbon dioxide and water are also produced.

Substances burn more strongly in pure oxygen. If a smouldering wooden splint is placed into a jarthat contains oxygen it will relight. This is a test for oxygen gas.

The fire triangle.The fire triangle shows the three things that are needed for burning to happen. Removing any ofthem stops a fire.


1) Burning is a chemical reaction between fuel and ______________

2) When carbon burns ______________ ______________ gas is produced.

3) Burning can be useful because it releases ______________

4) Most fuels are compounds of carbon and ______________

5) The test for oxygen is a smouldering ______________

6) The three things needed for a fire are oxygen, ______________ and heat.

7) A fire blanket is used to stop __________ getting to a fire.

8) Pouring water onto a fire takes away the ____________

9) Placing a damp cloth over a pan of burning fat stops __________ getting to the fire.


W.S.54. Products from chemical reactions. Name ………………………………

Most of the materials that we use every day have been made by chemical reactions. Some of themost common products are made from two important raw materials, METAL ORES and CRUDEOIL.

Metal ores.A few unreactive metals such as gold and silver are found as pure elements. However most metalsexist as compounds called ORES inside rocks. These ores must be reacted with other chemicals inorder to extract the metals that they contain. The more reactive the metal is, the more difficult it isto release from its ore. Metal ores often consist of the metal joined with oxygen (metal oxides). Ifthe metal is less reactive than carbon then it can be extracted by heating its ore with coke in afurnace. For example HAEMATITE (iron ore) contains iron oxide :

+

IRON OXIDE CARBON IRON

Crude oil.Natural oil from the ground is called CRUDE OIL. It contains a mixture of substances that can bechanged into many useful products. For example, small molecules extracted from crude oil can bejoined together to make larger molecules called POLYMERS. These are then used to make plastics.The diagram below shows the main products that are made from crude oil.

PLASTICS

SYNTHETIC RUBBER

SYNTHETIC FIBRES(e.g. nylon)

SOLVENTS(e.g. white spirit)

DETERGENTS

POLISHES + WAXES


1) Many useful materials are made by __________________ ___________________

2) An ore contains a _______________ joined to other elements.

3) If a metal is less _________________ than carbon it can be extracted using coke in a furnace.

4) Crude oil is a _________________ of useful substances.

5) Plastics and synthetic fibres are made of large molecules called _____________________


W.S.55. Harmful chemical reactions. Name ………………………………….

Some chemical reactions are harmful because they destroy our products. The corrosion of metalsand spoiling of foods through oxidation are two examples of this.

Corrosion of metals.Metals may be attacked by air, water or other substances around them. Usually the more reactivethe metal is, the faster it corrodes. The corrosion of iron and steel is called RUSTING. Theexperiment below shows that both air and water are needed for rusting to occur.

In dry air the iron naildoes not rust.

calcium chlorideto dry the air

In water without air theiron nail does not rust.

oil to keepout the air

In air and water theiron nail rusts.

rustiron nail

water

Rusting causes iron and steel structures to gradually flake away and weaken. To prevent rusting thesurface of the metal can be coated with a substance that will keep out air and water. Paint, grease,plastic, or a thin layer of tin or zinc can be used to protect iron and steel.

Oxidation of foods.Some food molecules react with oxygen gas in the air. This changes their flavour, making themtaste unpleasant. Fat molecules can be oxidised quickly, therefore fatty foods such as butter shouldbe kept in a fridge to slow down the rate of oxidation. Another method of preventing oxidation is tokeep air away from the food by using sealed packets or tins. For example, crisp packets are filledwith nitrogen gas to prevent oxidation of the crisps.


When the surface of a metal is attacked by air or water it ……………………. Usually if a metal isvery ……………………. it will corrode quickly. The corrosion of iron and steel is called……………………. Iron will only rust if it is exposed to both air and ……………………. We canprevent rusting by ……………………. the metal with a substance that keeps out ……………... andwater. This is why motor cars are given several layers of …………………….Some food molecules are ……………………. when exposed to air. This gives them an unpleasant……………………. Keeping foods ……………………. will slow down the rate of oxidation.Another way of preventing ……………………. is to make sure that the food does not come intocontact with air.

air rusting taste cool corrodes water oxidation coating oxidised reactive paint


W.S.56. Energy from chemical reactions. Name ………………………………

Chemical reactions involve energy changes. Heat may be taken in or given out during a reaction.Sound, light, mechanical or electrical energy may also be produced. Reactions which take in heatare called ENDOTHERMIC reactions. Most chemical reactions give OUT heat and are calledEXOTHERMIC reactions. When fuels are burnt they give out heat and light energy. Explosivefuels give out mechanical and sound energy as well. The chemical reaction that takes place inside atorch battery gives out electrical energy.

Energy from fuels.

Wood can be burnt as a fuel. Fossil fuels form over millions of years.

coal

All of the fuels above contain the elements carbon and hydrogen. Combustion (burning) of thesefuels in oxygen produces carbon dioxide, water and heat energy :

FUEL + OXYGEN CARBON DIOXIDE + WATER +

The heat energy can be used to keep our houses warm, to heat water and to cook food. The heatfrom fuels can also be changed into mechanical energy to drive engines.

Effects on the environment.The carbon dioxide that is produced when fuels burn is released into the air.The amount of carbondioxide in the atmosphere is increasing. Scientists think that this reduces the amount of heat thatescapes from the surface of the Earth back into space. This is called the GREENHOUSE EFFECTand it may lead to GLOBAL WARMING.Oil and coal release sulphur dioxide gas when they burn. This gas enters the atmosphere anddissolves in rain droplets to form ACID RAIN. In some parts of Europe acid rain has destroyedplant and animal life in lakes and forests. Acid rain also causes corrosion of buildings and statues.Burning coal can produce a lot of smoke and harmful fumes. Coal can be made into a smokelessfuel called COKE by heating it in the absence of air.


1) A chemical reaction that gives out heat is called an _________________________ reaction.

2) When fuels are burnt they give out heat and _________________ energy.

3) The chemical reaction inside a torch battery produces ____________________ energy.

4) Most fuels contain the elements carbon and _________________

5) Burning of fuels produces ______________ ______________ gas which may lead to globalwarming.

6) Burning of oil and coal releases ______________ _____________ gas which causes acid rain.

ENERGY


Metal Reaction with oxygen Reaction with water Reaction with acid

Potassium Burns fiercely with alilac flame.

Very fierce and ignites(catches fire).

Too dangerous to perform.

Sodium Burns fiercely with ayellow flame.

Fierce but it does notignite.

Too dangerous to perform.

Magnesium Burns with a blindingwhite flame.

Very slow reaction butit reacts with steam.

Very fast reaction thatproduces hydrogen gas.

Zinc Burns slowly with a dullred flame.

Reacts slowly withsteam.

Quite a slow reaction.Some hydrogen produced.

Iron Does not burn but itglows brightly.

Very slow reactionwith steam.

Very slow reaction.

Lead Melts but does not burn. No reaction. Extremely slow.

Copper Does not burn but itforms a black coating.

No reaction. No reaction.

Gold No reaction. No reaction. No reaction.

least reactive

most reactive

W.S.57. Reactivity of metals. Name ………………………………….

We can compare the way in which metals react in order to work out the REACTIVITY SERIES.This means to arrange the metals in order of most to least reactive. The three tests below are used tojudge how reactive different metals are :

Reaction with oxygen. Reaction with water. Reaction with acid.

Heat themetal.

oxygen

Drop the metalinto cold water.

water trough

gas jar

acid

hydrogengas

Exercise – Use the information in the table to help you complete the sentences below.

1) _________________ is the most reactive metal.

2) __________________ is the least reactive metal.

3) It is dangerous to add sodium to acid because sodium is ________________________________

4) You should not look directly at ____________________ when it burns in oxygen.

5) Gold does not corrode because ____________________________________________________

6) The reaction between a metal and water can be speeded up by using ______________________


W.S.58. Displacement reactions. Name ………………………………….

The more reactive a metal is the more readily it will form compounds, and the more difficult it is tobreak down these compounds. If two metals are placed together the more reactive metal will ‘win’any competition to form a compound. The experiment below shows a reaction between an iron nailand copper sulphate solution.

iron nail

blue copper sulphate IIsolution

A coating of copper isdeposited on the nail.

green solution

Iron and copper compete to be the compound in the solution. Iron is more reactive and so itDISPLACES (pushes out) the copper in the solution. This can be shown with a word equation :

IRON + COPPER SULPHATE IRON SULPHATE + COPPER (blue solution) (green solution)

A metal will always displace a less reactive metal from solutions of its compounds.

Exercise 1 – Study the experiment below and then try to complete the missing words in the spaces provided.

colourless silvernitrate solution

copper coin

solution goes blue

coin becomes silver

COPPER + SILVER NITRATE COPPER _________________ + SILVER (colourless) (blue)

Copper is _______________ reactive than silver therefore it displaces silver in the solution.

Displacement reactions with metal oxides.Displacement reactions can also take place between metals and metal oxides. In this case the twometals compete for oxygen. For example, if magnesium powder is heated with copper oxide there isan explosive reaction :

MAGNESIUM + COPPER OXIDE MAGNESIUM OXIDE + COPPER

Magnesium ‘wins’ the competition for oxygen because it is higher in the reactivity series thancopper. When a metal is heated with the oxide of a less reactive metal it will remove theoxygen from it.

Exercise 2 - Use your knowledge of the reactivity series to complete the chemical reactions below. If you do notthink there will be a reaction then write down ‘NO REACTION’.

iron + silver nitrate __________________________________________

zinc + magnesium oxide __________________________________________


STRONG WEAK STRONG WEAK

These are the poisonousmineral acids that areused in the laboratory :

- hydrochloric acid - sulphuric acid - nitric acid

ethanoic acid in vinegar

citric acid in fruit juices

lactic acid in sour milk

carbonic acid in sodawater

sodium hydroxide

potassium hydroxide

oven cleaner

washing powder

ammonia

soap

sodium bicarbonate (bakingpowder)

W.S.59. Acids and alkalis. Name ………………………………….

Acids are a group of chemicals that dissolve in water and show certain properties in common. Theyare CORROSIVE (eat into materials) and they react with some metals to form hydrogen gas and asalt. Acids have a sour taste, and many are poisonous. A purple dye called LITMUS changes to ared colour in acids.

Alkalis are the chemical opposites of acids, but some of them are also very corrosive. They dissolvein water and often have a soapy feel. Alkalis turn litmus blue and they can be used toNEUTRALISE (cancel out) acids. A NEUTRAL solution is neither acid or alkali.

Acids Alkalis

Universal Indicator and the pH scale.

Litmus paper can only indicate whether a substance is an acid or an alkali. It does not tell us howstrong an acid or alkali is. Universal indicator contains a mixture of indicators which change to anumber of different colours depending on the strength of the acid or alkali being tested. Universalindicator can be used in a solution or paper form. The colour change tells us the pH number of thesubstance being tested which is a measure of the strength of the acid or alkali.

1 2 3 4 5 6 7 8 9 10 11 12 13 14NEUTRAL

RED ORANGE YELLOW GREEN TURQUOISE BLUE VIOLET PURPLE

STRONG ACIDS WEAK ACIDS WEAK ALKALIS STRONG ALKALIS

Acids becoming stronger Alkalis becoming stronger

pH


1) If a chemical is ____________________ it will eat into other materials.

2) Acids react with some _______________ to produce hydrogen gas.

3) Litmus turns _____________ in acid and _____________ in alkali.

4) The pH is a measure of the ________________ of an acid or alkali.

5) A chemical with a pH number of six is a ________________ ________________


hydrochloric acid

hydrogen gas

W.S.60. Acids and metals. Name ………………………………….

Metals that are above copper in the reactivity series will react with acids to form hydrogen gas anda salt.

ACID + METAL HYDROGEN + SALT

The more reactive the metal is, the faster the reaction will be. The experiment below shows thereaction between hydrochloric acid and magnesium.

Hydrogen explodes witha lighted splint

magnesium ribbon

unreactedmagnesium

heat

water evaporates off

salt

1) The magnesium reactswith the acid.

2) A solution of magnesiumchloride has formed.

3) Magnesium chloridesalt is left behind.

Exercise – Complete the missing words in the sentences and equations below.

1) A metal must be more reactive than _____________ to react with an acid.

2) ACID + METAL HYDROGEN + __________

3) Reactive metals produce hydrogen F _ _ _ _ _ than unreactive metals.

4) The test for ________________ is a lighted splint.

5) Hydrogen is an __________________ gas.

6) hydrochloric acid + magnesium ___________ + magnesium chloride

7) All of the ___________ has reacted when there are no more hydrogen bubbles given off.

8) The __________ that has been made is magnesium chloride.

9) Magnesium chloride is ________________ in water.

10) It would be dangerous to add potassium to an acid because potassium is so _________________


hydrochloric acid

carbon dioxide

W.S.61. Acids and bases. Name ………………………………….

A base is any compound that can neutralise (cancel out) an acid. Bases that dissolve in water arecalled alkalis. A base reacts with an acid to form a salt and water :

ACID + BASE SALT + WATER

For example, if sodium hydroxide, which is a very strong alkali, is reacted with hydrochloric acidthen sodium chloride (common salt) is formed.

Reaction with carbonates.Carbonates are bases that contain the elements carbon and oxygen. They react with acids to form asalt, carbon dioxide gas and water. The reaction is fizzy due to the carbon dioxide gas given off :

ACID + CARBONATE SALT + CARBON DIOXIDE + WATER

The experiment below shows the reaction between calcium carbonate (marble chips) andhydrochloric acid.

1) The marble chipsreact with the acid.

2) A solution of calciumchloride has formed.

3) Calcium chloridesalt is left behind.

marble chips

unreactedmarble chips

heat

water evaporates off

salt

calcium carbonate + hydrochloric acid calcium chloride + carbon dioxide + water

Exercise – Complete the missing words in the sentences and equations below.

1) A ____________ is a chemical that can neutralise an acid.

2) Bases that dissolve in water are called ______________

3) Sodium ________________ is a strong alkali.

4) ACID + BASE ________ + WATER

5) Sodium _______________ is common salt.

6) Carbonates contain the elements carbon and _________________

7) Carbonates react with acids to produce _______________ _______________ gas.

8) Marble chips will F _ _ _ in acid until it has all been neutralised.


Powdered limestone isspread onto soil toneutralise excess acid.

W.S.62. Neutralisation. Name ………………………………….

Sometimes it is necessary to NEUTRALISE (cancel out) excess acids or alkalis. Chemicals calledBASES, which include alkalis, can be used to neutralise acids. The diagrams below show someexamples of this.

Acid indigestion


Sometimes ……………………. acids or alkalis cause problems. The stomach contains dilute…………………… acid. If there is too much acid in the stomach it causes ……………………….Tablets can be taken that contain a weak ……………………. to neutralise the excess acid.A bee sting is ……………………. and must be treated with a weak alkali such as sodium……………………. A wasp sting is alkaline and must be treated with a weak acid such as…………………….Soils and lakes can become too acidic, especially in areas that are polluted with acid ………………Blocks of ……………………. can be added to lakes to neutralise the excess acid and……………………. limestone can be spread onto fields.

powdered vinegar hydrochloric acidic excess limestone rain alkalibicarbonate indigestion

The stomach containshydrochloric acid. Excessacid causes indigestion.

Indigestion tabletscontain a weak alkalito neutralise the acid.

Insect stings

The sting injectspoison.

Acid soils and lakes

Acid rain falling onto soils andlakes can make them too acidic.

Blocks of limestone are addedto neutralise excess acid.

WASP STING - alkaline so treat it witha weak acid such as vinegar.

BEE STING – acidic so treat it with aweak alkali such as sodium bicarbonate.


W.S.63. Acid rain. Name ………………………………….

Oil and coal release sulphur dioxide gas when they burn. This gas enters the atmosphere anddissolves in rain droplets to form ACID RAIN. In some parts of Europe acid rain has destroyedplant and animal life in lakes and forests. Acid rain also causes corrosion of metal and chemicalweathering of rock.

SULPHURDIOXIDE

Carried by weather systems.

Sulphur dioxide mixes with water droplets in the atmosphereto form acid rain which falls onto lakes and forests.

Power stations burn fossil fuels inorder to generate electricity. Somefactories also burn fossil fuels.

Acid rain corrodes metalsand stonework. Limestonedissolves very quickly.

Acid kills fish andother water life.

Acid washes minerals out ofthe soil and kills plant life.

Exercise – Use the information in the diagrams above to help you complete the sentences below.

1) The main waste gas that causes acid rain is ______________________________

2) Sulphur dioxide is produced by the burning of ______________________________

3) A power station burns fossil fuels in order to generate ________________________

4) Sulphur dioxide gas mixes with ___________________________ in the atmosphere.

5) If a lake becomes too acidic the fish and other water life will __________________

6) Acid rain washes _____________________ out of the soil.

7) Acid rain corrodes _________________ and stonework.

8) _____________________ is a type of rock that dissolves quickly in acid rain.


W.S.64. Electric current and voltage. Name ………………………………….

Metals are good CONDUCTORS (carriers) of electricity. Most non-metals do not conductelectricity and we call them INSULATORS. An electric current will only flow through aCOMPLETE circuit. A chemical reaction inside the battery pushes the current from the negativeterminal to the positive terminal.

Voltmeterreads 1.5 V

current

The bulb uses the electricalenergy and lights up.

switchCLOSED

Ammeterreads 3A

No current

The bulb does not light up

switch OPENThe circuit isbroken

No readingon ammeter

Symbols

A cell (battery).

A switch. This connects twoleads.

A voltmeter. This measuresthe voltage across the batteryterminals.

An ammeter. This measuresthe size of the electriccurrent in AMPS (A).

A bulb. The brightness givessome idea of how muchelectricity is flowing.

The effect of increasing the voltage.

The diagram opposite shows what happens if two batteriesare put into the circuit. Carefully compare it to the firstdiagram at the top of this page and then try to completethe missing words in the passage below.

A battery pushes out the …………………... Thevoltage across both batteries can be measured using a………………………. With two batteries there is………….. the voltage. This produces twice thecurrent and so the bulb lights much …………………The negative end of one battery must be connected tothe ………….……. end of the other battery. If theyare connected the wrong way round the current willnot ……………..

The bulb is much brighter.

Voltmeterreads 3 V

switchCLOSED

Ammeterreads 6A


6 amps

W.S.65. Series and parallel circuits. Name ………………………………….

Exercise 1The diagrams below show the two ways of adding two bulbs to a circuit. Study them carefully andthen try to fill in the missing words in the passages underneath. Choose from the list of words at thebottom.

Bulbs in parallelBulbs in series

switchCLOSED

3 amps

The bulbs are dim.

switchCLOSED

6 amps

The bulbs are much brighter.

The current is ………………. because it isharder for it to travel through both bulbs.We say that there is a high ………………..The current does not get used up as it travelsaround the circuit. The ………………..would give the same reading anywhere inthe circuit. Adding another bulb in serieswould make them ………………..

Both bulbs are connected directly across thetwo batteries therefore they are given the full……………… The current is ……………...because it is ………………….. for it to flowaround the circuit. If a third bulb wasconnected in parallel they would all still beas ………… but the ……………….. wouldnot last as long.

voltage small batteries bright resistance larger dimmer ammeter easier

Exercise 2 – Study the two circuit diagrams below and then try to complete the sentences underneath.

open closed

A B

A

B

1

2

1) If the switch is opened in circuit 1 both bulbs __________________________

2) If bulb A is removed from circuit 1 the current would be ___________________ and bulb Bwould get ________________

3) If switch 1 is opened in circuit 2 only bulb _____ would light up.

4) If ammeters 2 and 3 in circuit 2 both read two amps then ammeter 1 will read _________ amps.

circuit 1 circuit 2

3 amps

3 amps

12

3


thinfilament

Copper wire makesa short circuit.

W.S.66. Electrical resistance. Name ………………………………….

When a bulb is connected into an electrical circuit thecurrent passes from the thick copper connecting wires,into the thin filament wire of the bulb, and then backout again. The filament does not let the current passthrough as easily. We say that it has a greaterRESISTANCE than the connecting wires. This causesthe filament to heat up and electrical energy is changedinto heat and light energy. If more bulbs are added inseries the total resistance in the circuit increases andthe current becomes smaller. This is why the bulbsappear dimmer.

Using resistors.The unit of resistance is the OHM (Ω). Differentmetals have different resistances. The resistance of awire also increases if it is made thinner or longer.RESISTORS are lengths of resistance wire that areused in circuits to reduce the current. They are used inelectrical devices such as radios and televisions inorder to keep the currents at the correct levels for thevarious parts. A VARIABLE RESISTOR consists of along coil of nichrome resistance wire. It has a slidingcontact that can be moved along the coil in order toalter the amount of resistance. The bulb in the circuitdiagram opposite can be gradually made dimmer orbrighter by sliding the control on the resistor.

Short circuits.An electric current will always take the easiest routearound a circuit. In the diagram opposite the bulb doesnot light up because it is easier for the current to passthrough the copper wire than through the bulb. Thebulb has a greater resistance than the wire. This iscalled a SHORT CIRCUIT.

Variable resistoralters brightnessof the bulb.

thick copperconnecting wire

Exercise – Complete the missing words in the passage below.

The thin wire inside a light bulb is called a F ……………… This does not let the C ………….. passthrough it very easily because it has a high electrical R ……………………. When a bulb lights,electrical energy is being changed into H ………… and L ………… energy. C……………… is ametal with a very low resistance which is why it is used for electric wires.The unit of resistance is the O …….. The T ………………. a wire is the less resistance it has.Resistors are used in electrical devices to prevent currents from becoming too H ……… A variableresistor is used to vary the size of the current in a circuit. They are used as dimmer switches inhousehold L ………… Variable resistors are also used as V ……………… controls in televisionsand radios.An electric current will always follow the path of least R …………………… in a circuit. If a lengthof wire is connected across an electrical device it can cause a S …………. circuit.


W.S.67. Magnets. Name ………………………………….

The magnetic metals are iron, steel, cobalt and nickel. They are attracted to magnets and canbecome magnetized themselves. There are invisible magnetic forces around a magnet. This is calleda MAGNETIC FIELD. The forces are most concentrated around the ends, which are called theNORTH (N) POLE and the SOUTH (S) POLE. Magnetic materials are attracted most strongly bythe poles of a magnet.

The field lines can be shown byplacing a piece of paper over themagnet and then sprinkling ironfilings on top. The iron filingsfollow the pattern of the field lines.

A compass always points fromnorth to south along the field lines.

N S

compass

field line

Forces between magnets.If the poles of two bar magnets are brought close together they will exert a force on each other.They will either ATTRACT (pull together) or REPEL (push away from each other). This dependson what type of poles are brought together :

N S NS NS

REPEL ATTRACT

The rule is : LIKE POLES REPEL AND UNLIKE POLES ATTRACT.

Exercise 1 – Write down whether the magnets will attract or repel underneath each of the diagrams below.

NS NN S S

1) ……………….. 2) ……………….. 3) ………………..

Exercise 2 – The diagrams below show three steel pins. Two of them are magnetized (have becomemagnets) and one is not. Work out which of the pins are magnets and write down the answer underneath.

pin A pin B

pin A pin C

pin B pin C

REPEL

ATTRACTATTRACT

Therefore the magnetic pins are _________


solenoid

W.S.68. Electromagnets. Name ………………………………….

When a wire carries an electric currentit produces a weak magnetic fieldaround it. The field can be madestronger by increasing the currentpassing through the wire.

wire carrying a current

weak magnetic field lines

The magnetic field can also be made stronger by winding the wire into a coil called a SOLENOID.The magnetic field that is produced is like the one around a bar magnet. The greater the number ofturns on the coil the stronger the magnetic field becomes.If an iron bar is placed inside the solenoid the magnetic field becomes much stronger. This iscalled an ELECTROMAGNET and it can be used in many devices, e.g. electric bells and relays.The diagram below shows how an electromagnet is made.

When the current is switched off the iron bar loses its magnetism. If a steel bar is put into thesolenoid it stays a permanent magnet after the current is switched off.

Exercise – Complete the sentences and definitions below.

1) When a wire carries an electric current it produces a ______________________________

2) The three ways of increasing the magnetic field around a wire are :

(i) _______________________________________________________________________

(ii) _______________________________________________________________________

(iii) _______________________________________________________________________

3) A solenoid is ___________________________________________________________________

4) An elecromagnet is ______________________________________________________________

5) Two uses of electromagnets are in __________________________________________________

6) When a __________ bar is put into a solenoid it remains a permanent magnet.

N S

iron barmagneticfield lines


W.S.69. Uses of electromagnets. Name ………………………………….

The diagrams below show how electromagnets are used in various devices. Study them carefullyand then try to complete the missing words in the passages underneath.

push switch

An electric bell.When the push …………… is closed thecurrent flows through the ………….. Theelectromagnet then attracts the iron …………The hammer moves and strikes the ………….As this happens the ………………... separateand the circuit is broken. The electromagnetis switched off and the hammer springs backto its original position. The contacts ………...again and the whole process is repeated.

clamp

springymetal strip

iron arm

contacts

hammergong

coil

electromagnet

electric cablechain

electromagnet

scrap iron and steel

Sorting scrap metal.In a scrap yard huge electromagnets can beused to separate iron and ……………. objectsfrom other materials. A thick …………….cable supplies electricity to the magnet. Theelectricity is switched …… to pick the metalsup and then switched …… in order to putthem down again.

Electromagnetic switches – RELAYS.Sometimes it is dangerous to switch on an electrical circuit directly. For example, a car startingmotor needs a current of over 100 amps. An electromagnetic switch or …………….. can be used toswitch the circuit on safely. The current in the input circuit is ………………. compared to thecurrent in the output circuit. When the switch in the ……………….. circuit is closed the magnet isswitched on. This pulls the iron ……………. towards it and the ………………… are closed. Themotor in the ………………… circuit is now switched on.

INPUT CIRCUIT RELAY OUTPUT CIRCUIT

electric motor

iron lever

switch contactselectromagnet


W.S.70. Speed. Name ………………………………….

The SPEED of a moving object is the DISTANCE it travels divided by the TIME that it takes.

SPEED = DISTANCE ÷ TIME or DISTANCE TIME

Units for speedmetres per second (m/s)miles per hour (mph)kilometres per hour (km/h)

The example below shows how to work out the average speed of a toy car when it travels betweentwo markers.

push

time = 0s marker 1 time = 5s marker 2

The car travels a distance of 10m in 5s.

The average speed of the car = distance = 10m = 2m/s time 5s

Exercise 1 – Use the example above to help you work out the answers to the problems below. REMEMBER UNITS.

1) A sprinter runs 100m in 10 s. His average speed = 100m = _____m/s 10s

2) A train travels 600km in 5 hours. Its average speed = 600km = __________ 5h

3) A boy cycles 20 miles in 2 hours. His average speed = __________ = _____mph

4) A car travels 200 miles in 4 hours. Its average speed = __________ = __________

Working out distance and time.If we know the speed of a moving object we can work out whatdistance it will travel in a certain time. We can also work out howmuch time it will take to travel a certain distance. You can usethe formula triangle on the right to work out speed, distance ortime. For example, if you wish to work out distance then placeyour finger over the distance part (D) and you will see thatdistance is speed × time (S × T).

Exercise 2 – Use the formula triangle to help you work out the problems below. REMEMBER UNITS.

1) A car travels at 40 mph. What distance will it travel in 3 hours?

distance = __________ × __________ = __________ × __________ = __________

2) An athlete sprints at a speed of 10m/s. How long does it take him to complete a 200m race?

time = __________ = __________ = __________

S × T

D


Table pushes upwith a force of 5N.4

These forces are ……………………. so thebook does not ……………..

Exercise – For each of the diagrams below write down if the forces are BALANCED or UNBALANCEDand then complete the rest of the sentences.

W.S.71. Force and movement. Name ………………………………….

A FORCE is a PUSH or PULL. Force is measured in NEWTONS (N). Forces can speed up or slowdown objects. The diagrams below show how different forces can affect the movement of a car.

unbalanced force unbalanced force balanced force

1. Force from the enginemakes the car begin to move.

2. As the car speeds up the forces of airresistance and friction become greater.

3. The car reaches a steady speedwhen the two forces are equal.

When the forces pushing against the car are the same size as the force from the engine the car stopsaccelerating and travels at a steady speed.

Forces can also make objects change direction. The diagram below shows an example of this.

1. Shuttlecock movingin one direction hitsthe racket with a force.

2. The racket gives a force tothe shuttlecock and causes itto change direction.

Force from engineis 500N.

Force of airresistance is 300N.





1These are ……………………. forces. Thecar will ……………………………………..



A book is pulled downwith a force of 5N.

The important rules from this are :

1. Unbalanced forces change the speed and/or direction of moving objects.2. Balanced forces produce no change in the movement of an object.


surface of shoe.

W.S.72. Friction. Name ………………………………….

Friction is a force that stops twosurfaces sliding past each other.It is caused by tiny bumps onthe surfaces which ‘catch’together. Friction can be usefulbut it can also be a nuisance. surface of ground.

Uses of friction. Problems caused by friction.

1. Friction gives grip for shoes and tyres.We could not move over the ground withoutfriction.

2. Brakes on bicycles and cars use frictionto slow down the wheels.

1. Moving machinery is slowed down byfriction. Friction can also cause machineryto over heat. Grease and oil must be used toreduce friction.

2. Air resistance is a type of friction thatslows down vehicles. The faster the vehicletravels the greater the air resistancebecomes. Car bodies are designed so thatthe air slips smoothly over the bonnet.

bicycle tyre

rubber brakeblock

blocks grip wheelrim to slow it down

3. Air resistance is a type of friction thatslows down parachutes to a safe speed.

air resistancepushes upwards

the force of gravity pullsdown on the mass.

Poor design – air hits against bonnet andslows the car down. The engine mustwork hard to keep at a high speed.

Good design – air slips smoothly overthe bonnet. The air resistance is low andthe car travels at high speed easily.

Exercise – Complete the missing words in the passage below.

The force that prevents two surfaces from sliding past each other is called ……………….. If therewas no friction between our shoes and the ground our feet would …………... when we tried towalk. Rubber brake blocks grip against the ……….. of a bicycle wheel in order to slow it down. Aparachute reaches a steady speed when the force of gravity pulling it down is balanced by the……… …………………… pushing it upwards. Friction between the moving parts of machinerycan cause it to over …………. The friction can be ……………….. by using oil or grease. The……………….. a car moves the greater the air resistance is that pushes against it.


pivot

pivot

W.S.73. Turning forces. Name ………………………………….

Forces can cause objects to turn around a pivot.

The lever exerts alarge upward forceon the heavy rock.

load

A small downwardforce on the LEVER(plank) quite easilylifts the heavy rock.

A log is the PIVOT(turning point).

The important rule from this is :

The size of the turning force can be increased by increasing the length of the lever.

Exercise – Use the diagrams above to help you complete the sentences below.

1) A __________ is a turning point.

2) A long __________ makes it easy to move a heavy object.

3) The longer the lever the greater the ______________ __________ that is produced.

4) A ______________ can be used to lever open a locked door.

5) A tight nut can be loosened more easily if a ____________ spanner is used.

Some examples of how we use turning forces.

Using a spanner to loosen a nut.

apply force

apply force

Using a crowbar to force objects apart.

Using a wheelbarrow to carry heavy loads.

pivot

apply force


W.S.74. Moments. Name ………………………………….

A turning force is called a moment. The size of a moment depends on the distance from the pivotand the amount of force that is applied.

pivot(centre of nut)

apply a force of 10N here

0.3m

moment = force (N) × distance from the pivot (m)

= 10N × 0.3m = 3Nm

If the spanner was 0.5m long what would the size of the moment be?

answer = 10N × 0.5m = 5Nm

Therefore if the distance from the pivot is increased the size of the moment increases. This is why itis easier to loosen a tight nut with a longer spanner.

Balanced moments.In the diagram below different masses have been placed on both sides of a metre rule. The rulestays balanced because the masses are at different distances from the pivot. The calculationunderneath shows that the moments of the two masses exactly balance each other.

40N 20NANTICLOCKWISEMOMENT CLOCKWISE MOMENT

0.2m 0.4m

anticlockwise moment = 40N × 0.2m = 8Nm clockwise moment = 20N × 0.4m = 8Nm.

We can unbalance the moments by moving one of the masses along the rule, or by adding extramass to one side. For example, if extra mass is added to the left hand side the anticlockwisemoment will be greater than the clockwise moment and the rule will rotate anticlockwise.

Exercise – Work out the clockwise and anticlockwise moments in the diagrams below and then predict whatwould happen in each case.

Problem 1 Problem 2

pivot

20N 40N

anticlockwisemoment

clockwisemoment

3m 2m

pivot

40N 60N

clockwisemoment

3m 2m

pivotanticlockwisemoment


Coin spreads the forceover a large area.

10N The pin point concentratesthe force into a tiny area.

W.S.75. Pressure. Name ………………………………….

Pressure is the amount of force that is put onto a certain area. A force can produce differentpressures depending on the amount of area that it acts over.

high pressure

The coin does notgo through the table.

thumb

10N

The pin does gothrough the table.

thumb

low pressure

PRESSURE (N/m2) = FORCE (N) Another unit for pressure is the pascal (Pa) AREA (m2) 1 N/m2 = 1 Pa

Small pressure. Large pressure.A force is spread over a large area. A force is spread over a small area.

Working out force and area.You can use the formula triangle on the right to work outpressure, force and area. For example, if you wish to work outforce then place your finger over the force part (F) and you willsee that force is pressure × area (P × A).

Exercise – Use the formula triangle to help you work out the answers to the questions below.

1) A man weighs 800N. The area of one of his boot heels is 0.01m2 . What pressure does he placeon the ground when he puts all of his weight onto one heel?

2) A woman weighs 500N. The area of one of her stiletto heels is 0.0002m2 . What pressure doesshe place on the ground when she puts all of her weight onto one heel?

3) The base of a suitcase has an area of 0.2m2. It places a pressure of 700N/m2 on the ground.What must the weight of the suitcase be?

P × A

F

Knife edge – large pressure to cut into materials.

Stiletto heelWhen all of the woman’sweight is resting on theheel it produces a verylarge pressure. This cancause damage to floorswith soft surfaces.

Snow shoesThese spread a person’sweight over a large areawhich prevents them fromsinking into soft snow.

WashersA washer spreads theforce from the nut whichstops it being pulled intowood.


W.S.76. Reflection. Name ………………………………….

We can see objects because light travels from them into our eyes. LUMINOUS objects make theirown light, e.g. the Sun, a light bulb and a candle. Most objects are NON-LUMINOUS which meansthat they do not make their own light. We can see them because light bounces off them into oureyes. This is called REFLECTION.

Exercise – Use the information above to help you complete the questions below.

1) A ________________ object gives off its own light.

2) Underline the objects below that give off their own light.

TORCH BOOK CANDLE MIRROR GLOW WORM BOTTLE MOON SUN COIN FIREWORK

3) We can see our ____________________ in shiny, smooth surfaces.

4) Complete the diagrams below.mirror

1. Light rays travelaway from the bulbin all directions. 2. A ray reflects

off the book.

3. The ray enters theeye and the personsees the book.

Mirrors.Most surfaces are uneven which makes the light bounce off them in all directions. Mirrors have avery smooth, shiny surface. All of the light rays bounce off them at the same angle. This is whatmakes a clear REFLECTION.

Light rays are reflected off paper in all directionsdue to its rough surface.

Light rays hitting a mirror are all reflected at thesame angle due to its smooth surface.

The rays that hit the mirror are called the INCIDENT RAYS. The diagram above shows that theREFLECTED RAYS leave the surface of the mirror at the same angle that they came in at.

The law of reflection is :

The angle of reflection is equal to the angle of incidence.

normalline normal

line

45°


normal

LIGHT BEAM - FAST

W.S.77. Refraction of light. Name ………………………………….

normalAny material that light can travelthrough is called a MEDIUM.When light rays travel from onemedium to another they bend.This is called REFRACTION.The diagram opposite shows howa ray of light bends as it travelsfrom air, into a glass block, andout again.

Exercise – Complete the sentences and diagram below.

1) Any material that light can travel through is called a ____________

2) The bending of light is called ____________________

3) Light travels more ____________ in glass than it does in air.

4) Light bends when it passes from one medium to another because of the change in __________

Complete the diagram below to show why the coin appears higher in the water than it really is.

AIR

incident ray

Incident ray bendstowards the normal.

Refracted ray bendsaway from the normal.

GLASS

How refraction happens.The light bends because it travels more slowly in glass than it does in air. This can be compared to acar that travels more quickly on a road than it does on sand :

This wheel slowsdown first.

SAND

AIR

GLASS

LIGHT BEAM - SLOW

EYE

The coin appearsto be here.


W.S.78. The spectrum. Name ………………………………….

A PRISM is a triangular glass block. If a beam of white light is passed through a prism it isREFRACTED (bent). The light is also split up into a range of colours called a SPECTRUM.

Therefore white light is a mixture of seven different colours. This spreading out of colours is calledDISPERSION. It also happens when light hits rain drops which is how rainbows form. An easy wayto remember the order that the colours appear in is to remember this rhyme :

Richard Of York Gave Battle In Vain.

The effect of coloured filters on white light.A FILTER only allows one colour of light to pass through it. The filter ABSORBS the other coloursso they do not pass through.

Exercise – Complete the sentences and diagram below.

1) The name for a triangular glass block is a __________

2) The range of colours in white light is called the ________________

3) The spreading out of the seven colours is called ____________________

4) The colour that is bent the least by a prism is __________

5) The colour that is bent the most by a prism is __________

Complete the diagram below to show what would happen to the light as it meets the two filters.

Red – bent the leastOrangeYellowGreenBlueIndigoViolet – bent the most

White light entersthe prism.

SCREEN

redorangeyellowgreenblue

indigoviolet


indigoviolet

a red filter a blue filter


indigoviolet

a red filter a blue filter

PRISM


Item of clothing In white light In red light In green light In blue light

white shirt

red tie

blue jeans

green belt

GREEN BOOK

Only green lightis reflected intothe eye.

RED BOOK

White light containsseven colours.

W.S.79. Coloured objects in coloured lights. Name ……………………………

A white object reflects all seven colours of the spectrum. A red object looks red because it onlyallows red light to reflect off it. The rest of the colours of the spectrum are absorbed by the object.

R O Y G B I VOnly red lightis reflectedinto the eye.

In red light the red book still looks red because it reflects the red light. If the book is placed in anyother colour of light it will absorb the light . No light is reflected off the book into the eye and ittherefore looks black.

Exercise – For the items of clothing in the table below write down the colours that they would look in thedifferent lights shown.

R O Y G B I V

RED BOOK

The book stilllooks red.

red light

RED BOOK

The booklooks black.

blue light

The important rule from this is :

Coloured objects only reflect their own colour light.

no reflection


W.S.80. Hearing. Name ………………………………….

We hear things when SOUND WAVES pass into our ears. The diagram below shows the parts ofthe human ear and how we hear.

Hearing ranges.The range of pitches that a person can hear is called their HEARING RANGE. Different peoplehave different hearing ranges. Usually young people can hear higher pitched sounds than olderpeople. Young people can also hear quieter sounds.

Hearing damage.The sense cells in the cochlea are very delicate. If a person is exposed to very loud noises over along period of time the sense cells can become damaged and the person can become partially deaf.This is why people who work in very noisy places must wear ear protection. This is also the reasonwhy it is dangerous to listen to personal stereos at too high a volume.

Exercise – Join up the parts of the ear in the left-hand column with their correct descriptions on the right.

Part of ear Description

ear drum a tube that carries sound waves to the ear drum

ear canal a tight sheet of skin that vibrates when sound waves hit it

semi-circular canals sends nerve messages to the brain

auditory nerve contain fluid that swirls around when the head moves – gives balance

ear bones contains the sense cells that detect vibrations inside the ear

cochlea pass the vibrations from the ear drum to the cochlea

Sound wavesenter the ear.

pinna

ear canal

ear drum (vibrates whensound waves hit it.)

semi-circular canals (fluid swirls inside of themwhen the head moves. This gives the sense of balance.)

Tube that leadsto the throat.

To the brain

auditory nerve (carries nerveimpulses from the sense cells tothe brain.)

cochlea (contains fluid and sensecells. Vibrations carried in the fluidstimulate the sense cells.)

ear bones(carry vibrationsto the cochlea.)


Sound wavestuning fork

Vibrating forks makethe air vibrate.

W.S.81. Sound. Name ………………………………….

Sound waves.Sound waves are made by vibrating objects. Thediagram opposite shows a tuning fork that has justbeen struck. The ends of the fork are vibrating(moving backwards and forwards) very quickly.This makes vibrations in the air around the forkswhich produces sound waves.

Loudness and pitch.The shape of sound waves can be studied using anoscilloscope. The diagram opposite shows soundwaves on the oscilloscope screen. The bigger theAMPLITUDE (height of the waves) the louder thesound. The greater the FREQUENCY (number ofwaves per second) the higher the PITCH of thesound. A short wavelength gives a high frequency.

oscilloscope

amplitude

wavelengthThe frequency is the number ofwaves per second.

HIGH PITCH AND QUIET = ___ HIGH PITCH AND LOUD = ___

LOW PITCH AND QUIET = ___ LOW PITCH AND LOUD = ___


1) Sounds are made by __________________ objects.

2) Sound travels as ___________

3) The __________________ means the height of a sound wave.

4) The __________________ means the number of waves in one second.

5) The greater the frequency the ______________ the pitch.

6) The longer the wavelength the ______________ the frequency.

Exercise 2 – Match the diagrams to their correct descriptions below.

A B C D


W.S.82. Comparing light and sound. Name ………………………………….

In air light travels at a speed of 300,000,000 metres per second. Sound travels much more slowly ata speed of about 330 metres per second. This is why we see an exploding firework just before wehear it.

explodingfirework Sound takes longer to reach

your ears.

Light reaches your eyes first.

Light can only travel through TRANSPARENT materials such as water and glass. Sound must havea MEDIUM (substance) to travel through because something is needed to pass on the vibrations.Sound travels better through solids than it does through air.

Sound in a vacuum.Sound needs a material to travel through. It cantravel through solids, liquids and gases. Thediagram opposite shows a bell jar that contains anelectronic buzzer. As the air is gradually pumpedout of the jar the sound of the buzzer becomesquieter. When there is no air left inside the jar (avacuum) the buzzer cannot be heard. SOUNDCAN NOT TRAVEL THROUGH A VACUUM.

Air is pumped out.

electronic buzzer(the sound getsquieter until it canno longer be heard)

bell jar


1) The speed of light is much __________ than the speed of sound.

2) Light can only travel through _______________ materials.

3) You __________ a firework before you __________ it.

4) Sound needs a __________ to travel through.

5) __________ cannot travel through a vacuum.

6) __________ can travel through a vacuum.

7) Whales can communicate with each other over several miles of ocean because ______________

_____________________________________________________________________________


W.S.83. Day and night. Name ………….……………………...

The Earth spins around an imaginary line called its AXIS. The axis runs from the North to theSouth pole. The Earth makes one complete revolution every twenty four hours (one day). Duringthe day we face towards the Sun and at night we face away from the Sun.


The imaginary line that the Earth spins around is called its ……………….. It takes one …………...for the Earth to make one complete rotation. The Sun and the other …………………… APPEARto move across the sky due to the Earth’s ……………………. During the day we face……………….. the Sun and at night we face ……………….. from the Sun. The Sun rises in the……………….. and sets in the ………………... Our shadows are longest in the……………………. and in the evening. This is because the Sun is ……………….. in the sky. Atmidday the Sun is at its ……………….. in the sky.

towards stars away rotation low day axis East West morning highest

SUN

Sunrise and sunset.The Sun and other stars APPEAR to slowly move across the sky. This is due to the Earth’s rotation.We say that the sun RISES in the EAST and SETS in the WEST.

WEST(evening)

EAST(morning)

midday

Long shadow inthe morning.

Long shadow inthe evening.

stick

The Earth rotates around its AXIS.

nightday

Britain

sunlight

N

S


WinterShort days andlong nights.

SummerLong days andshort nights.

W.S.84. The seasons. Name ………….……………………...

It takes 365 days and 6 hours for the Earth to complete one orbit of the Sun. We make one year 365days but every four years we need to add on an extra day to make up for the six extra hours. This iswhy a LEAP year has 366 days.During a year in Britain the weather gradually changes from warm Summer to cold Winter andback again. The different SEASONS are caused by the tilt of the Earth on its axis. The diagrambelow shows how this happens.

Exercise – Study the diagram above and then try to complete the sentences below.

1) One complete circle around the Sun is called an __________

2) One year is the length of time it takes for the Earth to ___________________________________

3) In Summer we have warm weather and long days because the Northern Hemisphere is ________

__________________________________________________

4) In Winter the Northern Hemisphere is tilted ______________________ the Sun.

5) Australia is in the Southern Hemisphere so in December it is their ____________

6) In ______________ the Sun is at its highest in the sky and in Winter it is at its lowest.

7) In ______________ and ______________ Britain is not tilted towards or away from the Sun.

SpringOn March 21st there is equal lengthday and night.

AutumnOn September 21st there is equal lengthday and night.

SUN

Britain is tiltedaway from theSun.

Britain is tiltedtowards the Sun.


W.S.85. The solar system. Name ………….……………………...

The Sun and other stars are sources of light. Planets orbit stars and do not produce their own light.We can sometimes see the moon and some of the planets at night because they REFLECT lightfrom the Sun. The SOLAR SYSTEM is our Sun together with the nine planets that orbit it. Theorder of the nine planets starting with the one closest to the Sun is :

Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, Pluto

An easy way to remember the order of the planets is to remember this rhyme :

My Very Easy Method Just Speeds Up Naming Planets.

The diagram below gives an idea of how far the planets are from the Sun.

SUN

M V E M J S U N P

. . . . . . . . .5,900 million km.

The diagram below gives an idea of how the planets compare in size. The length of each planet’syear (orbit time) is also given underneath each one (d = days, y = years.)

M V E M

U N P

J S

88d

225d 365d687d

12y

29y84y 165y

248y

THE FURTHER THE PLANET IS FROM THE SUN THE LONGER IT TAKES TO ORBIT.

Exercise – Use the information above to help you complete the sentences below.

1) The planet that is closest to Earth is _____________

2) The largest planet is ______________

3) The further the planet is from the Sun the ______________ is its year.

4) The planet with a year about twice as long as Earth’s is ____________

5) The planets with a shorter year than Earth are ________________________________________

6) The planets that are very near to the ____________ have very high temperatures.

7) The rings around ______________ are easily seen.


W.S.86. Satellites. Name ………….……………………...

The planets are attracted towards the sun by an invisible force called GRAVITY. This is what keepsthe planets in orbit. In the same way the Moon orbits the Earth because of the pull of gravitybetween them. Any object that travels around a planet in this way is called a SATELLITE. Humanshave sent artificial satellites into space. These are very useful in several ways.

The Moon is our natural satellite. Artificial satellites.

Moon

Artificial satellites have the following uses :

1. To observe and photograph the Earth.2. To study weather systems.3. To send radio and TV signals around the

world.4. To look deeper into Space. In Space there

is no atmosphere (air) to cloud our view.The Hubble telescope is a satellite that hashelped us to discover more about theUniverse.

The Moon travels anticlockwise around theEarth. It takes 27.3 days to complete oneorbit. During this time the Moon appears tochange shape from a full moon to nothing andthen back to a full moon again. This happensbecause we only see the part of the Moonwhich reflects light from the Sun. The partthat is in shadow does not show up. We seedifferent amounts of the lit side as the Moontravels around the Earth. Early people usedthis cycle to keep track of the months.


Gravity is an invisible ……………….. that keeps the planets in orbit. The Moon orbits the Earthbecause of the pull of ……………….. Any object that orbits the Earth is called a ………………….The ………………. is the Earth’s natural satellite. The Moon travels ……………………. aroundthe Earth. It takes about twenty seven days for the Moon to complete one ……………….. Duringthis time the Moon appears to change shape from a ……………….. moon to nothing and then backagain.If a satellite is given too much ……………….. it will escape into Space. If it has too little speed theforce of gravity will pull it back down to ……………….. The Hubble ……………….. is a satellitethat helps us to see much more clearly into Space. It can do this because in Space there is no……………………. to block our view.

Earth full anticlockwise atmosphere speed telescope gravity Moon forcesatellite orbit


W.S.87. The Moon and its phases. Name ………….……………………...

The Moon appears to change shape as it travels around the Earth. This happens because we only seethe part of the Moon that reflects light from the Sun. The diagram below shows how this happens.

The changing appearance of the Moon is called its PHASES. The complete cycle from one newMoon to the next takes 29.5 days even though it only takes the Moon 27.3 days to completely orbitthe Earth. The difference between these two times is because the Earth also gradually changesposition as it orbits the Sun.

Gravity on the Moon.The Moon has a much smaller mass than the Earth. This makes its pull of gravity six times smallerthan the Earth’s. This means that if you weigh 600N on Earth you would only weigh 100N on theMoon. This is why an astronaut feels very light on the Moon and can jump six times higher thanthey can on Earth. The bigger the mass of a planet the bigger its force of gravity. Therefore largeplanets have a large gravity and small planets have a small gravity.


1) The changing appearance of the Moon is called its ______________

2) We cannot see the Moon when it is a __________ Moon.

3) A __________ Moon appears 14 days after a new Moon.

4) The Moon has a much ________________ mass than the Earth.

5) You would weigh _________ times less on the Moon.

6) The smaller a planet is the ________________ its gravitational force is.

SUNA full moonat 14 days.

A half moonat 7 days.

A half moonat 21 days.

A crescent moon.

A new moonat 0 days.


W.S.88. Energy resources. Name ………….……………………...

The World’s population uses a huge amount of energy every day. Most of the energy that we use toheat our homes and to power our machines comes from FOSSIL FUELS. These are coal, oil andnatural gas. It takes millions of years for fossil fuels to form from the remains of dead plants andanimals. We say that they are NON-RENEWABLE because once we have used them up we cannotreplace them. In the future we will need to rely more upon RENEWABLE energy resources (thosethat will not run out).

Renewable energy resources.


1) Most of the energy we use in our homes comes from ___________________________________

2) We say that fossil fuels are ____________________________ because they cannot be replaced.

3) In the future we will need to rely more upon ____________________ energy resources.

4) Biofuels come from ________________________________________

5) Wind and solar power will never run out but _______________ conditions are not always suitable to use them.

6) The energy in waves can be used but it is ____________________ to set up.

Biofuels – from plants and animals. Solar power

Wood can be burnt.

Alcohol can be made from plantsand then used instead of petrol.

SUNLIGHT Solar panels and solarcells capture the Sun’senergy. It must be asunny day.

Wind power Wave power

Sailing-boats use wind powerto move them. Wind turbinesare used to produce electricalenergy. It needs windy weather.

The movement ofwaves on the sea canbe used to drivegenerators. This isexpensive to set up.

Gravitational energy

Water is stored at a height in dams. Asit rushes downhill gravitational energyis changed to moving energy. This canbe used to turn turbines which produceelectricity.


W.S.89. The Sun and energy resources. Name ………….……………………...

Most of the energy on Earth ultimately comes from the Sun. The diagram below shows how we canalways trace energy resources back to energy from the Sun. Study it carefully and then try tocomplete the exercise below.

Sun

Solar panels absorbenergy and use it toheat water.

Solar cells absorb lightenergy and convert itinto electrical energy.

Heat is absorbed by theatmosphere and causeswinds which can be usedto turn wind turbinesand produce electricalenergy.

Heat absorbs water vapour from the oceanswhich then falls as rain onto the land. Aswater rushes down from dams it can be usedto turn turbines which produce elecricity.

Plants trap lightenergy and storeit in food.

Energy in food. Wood can be burnt as a fuel. Fossil fuels form over millions of years.

Exercise – Use the information in the diagram to help you complete the sentences below.

1) When wood is burnt the energy that is released originally came from the Sun because ________

_____________________________________________________________________________

2) Fossil fuels are formed from the remains of __________________________________________

3) ____________________________ can be used to absorb heat directly from the Sun.

4) Winds are caused by ______________ from the Sun being absorbed into the atmosphere.

coal


W.S.90. Generating electricity. Name ………….……………………...

Electricity is a very useful form of energy. Most people use electricity many times every day.Electricity is GENERATED (produced) in power stations before it is sent to homes and factories. Anumber of energy resources can be used to generate electricity. In this process large TURBINESthat are connected to GENERATORS are made to turn. As the generators turn they produce theelectricity. The diagram below shows how this works.

TURBINES are made to turnby some form of energy. Thiscan be wind, moving water,or steam under high pressure.

The turbines are connected to aGENERATOR. As this spinsaround it generates electricity.

Cables carry awaythe electricity.

Many power stations burn coal in order to heat water. As the water boils steam is produced underhigh pressure. The turbines are pushed around by the force of the steam. Only about one third of thechemical energy inside the coal is changed into electrical energy. The other two thirds of the energyis lost to the environment as heat.Some power stations use wind power to push the turbines around. In a HYDROELECTRIC powerstation water rushing downhill from a lake is used to turn the turbines.


1) In order to generate electricity large turbines must be made to __________

2) The electricity is actually made inside the ____________________

3) In many power stations pressure from ____________ is used to turn the turbines.

4) Many power stations use __________ as the fuel to heat water.

5) Coal powered electricity stations are wasteful because _________________________________

____________________________________________________________________________

6) Hydroelectricity is generated by using energy from ______________________

7) In the future wind and water power may become the main ways of generating electricitybecause they will never ____________________

TurbinesGenerator


W.S.91. Energy transfer. Name ………….……………………...

There are several forms of energy. These are :

* HEAT ENERGYLIGHT ENERGYSOUND ENERGYELECTRICAL ENERGYKINETIC ENERGY - movement energy.GRAVITATIONAL ENERGY - energy stored in objects that are at a height.ELASTIC ENERGY - energy stored in stretched objects e.g. a spring.CHEMICAL ENERGY - energy stored in chemicals e.g. fuels, batteries and food. It is released by chemical reactions.

* It is easy to confuse the words heat and temperature. The diagram below shows the differencebetween these two terms.

The cup of soup is at the same temperature asthe pan of soup because each soup moleculehas the same amount of kinetic (moving)energy. The pan of soup holds more heat thanthe cup of soup because it is much bigger.

Energy is always changing from one form into another. We call this ENERGY TRANSFER.

Exercise – The diagrams below show various energy transfers. For each one write down the form of energyat each stage. The first one has been done as an example.

light

light

1) CHEMICAL ELECTRICAL HEAT + LIGHT

2) GRAVITATIONAL ……………….

3) ……………… HEAT + …………..

4) ……………. …………………….

5) ……………… HEAT ………………..

6) ……………….. …………..tuning fork

coal


W.S.92. Conservation of energy. Name ………….……………………...

There is an important law about energy called the CONSERVATION OF ENERGY :

Energy can change from one form into another, but it cannot be created or destroyed.

This means that the amount of energy we put into a machine is equal to the amount of energy thatcomes out. The diagram below shows what happens to the energy in a car with a petrol engine.

Energy is always wasted in machines and electrical devices. We say that the car is 20% efficientbecause it only converts 20% of the energy in petrol into USEFUL energy (kinetic).Generating electricity by burning coal is quite wasteful because only about one third of thechemical energy inside the coal is converted into electrical energy. The other two thirds is lost tothe environment as heat energy.

Exercise – Work out the missing numbers in the diagrams below.

4) In what way is a diesel engine better than a petrol engine?

________________________________________________________________________________

1)

2)

3)

100 units of energyin petrol.

80 units lost as heat.

20 units convertedinto kinetic energy.

= 20% efficient

power station

100 units of energyin coal.

37 units converted intoelectrical energy.

= 37% efficient


100 units of energyin diesel.


…… units convertedinto kinetic energy.

= % efficient

100 units of electricalenergy.


…… units convertedinto light energy.

= % efficient

100 units of heatenergy.

…… units lost to the air.

20 units transferred tothe soup.

= % efficient

Answers to exercises. 97

Worksheet 1 Life processes.

Exercise 1 1) life processes 2) animals move more quickly 3) energy 4) sensitivity 5) reproduce 6) carbon dioxide 7) excrete

Exercise 2 Processes a car does show Processes a car does not show

movement growth

nutrition (takes in petrol) sensitivity

respiration reproduction

excretion

Worksheet 2 Plant and animal organs.

Exercise 1 type organs body functions healthy plants system intestines

Exercise 2 brain heart leaf stomach flower lungs

Worksheet 3 Animal and plant cells.

Exercise 1 animals cells single millions types parts

Exercise 2 Cell part Function (job)

Nucleus covers the membrane and gives strength to a plant cell.

Cytoplasm controls what the cell does.

Cell wall a jelly that fills the cell, chemical reactions happen here.

Chloroplast stores water in a plant cell.

Vacuole absorbs light energy in order to make food for the plant.

Worksheet 4 Different cells for different jobs.

Exercise 1 nucleus different shape adapted body job efficiently

Exercise 2 sperm cell root hair cell ciliated cell palisade cell

Worksheet 5 A balanced diet.

Exercise 1 healthy types fats correct starch energy warm protein repair vitamins intestines

Exercise 2 potato – carbohydrate, fish – protein, fruit – vitamins, minerals and fibre, sausages – protein and fat, whole grain bread – carbohydrate and fibre, milk – protein and minerals, chicken – protein, cake – carbohydrate

98

Worksheet 6 Food and digestion.

Exercise 1 repair fuel heat cells digestive intestines

Exercise 2 clockwise from top right :

gullet stomach pancreas small intestine rectum anus appendix large intestine liver gall bladder salivary gland tongue

Worksheet 7 Stages of digestion.

mouth gullet stomach small intestine pancreas liver large intestine appendix rectum

Worksheet 8 Blood.

plasma red dissolved oxygen white germs platelets cut scab

Worksheet 9 The blood system.

vessels veins pump body heart narrow cell blood

Worksheet 10 Moving the body.

joints move muscles fibres shortens tendons push pairs biceps triceps

Worksheet 11 Growing up.

Exercise 1 children puberty body attracted hormone changes oestrogen

Worksheet 12 The human reproductive system.

sperm outside penis tube swim urine ova month oviducts placenta food

Worksheet 13 The menstrual cycle.

1.) month2.) 14 days3.) becomes thicker as many blood capillaries grow in it4.) die5.) the woman has her period / blood and dead cells pass out through the vagina

Worksheet 14 Ovulation and fertilisation.

1) ovulation 2) fertilisation 3) oviduct 4) divide 5) cells 6) uterus 7) muscle8) blood vessels

Worksheet 15 The developing baby.

amnion placenta blood chemicals oxygen waste

Worksheet 16 Breathing (1).

oxygen trachea cartilage bronchus alveoli capillaries blood

Answers to exercises.


Worksheet 17 Breathing (2).

1) thorax 2) muscle 3) inhale 4) exhale 5) contract 6) volume 7) decrease 8) relax 9) pressure

Worksheet 18 Keeping the lungs clean.

1) a thick, sticky liquid called mucus2) dirty mucus up to the throat where it is swallowed3) beating4) the gas carbon monoxide stops the blood carrying as much oxygen around the body5) cancer

Worksheet 19 Respiration.

Exercise 1 oxygen on left-hand side, carbon dioxide and water on right-hand side

Exercise 2 1) energy2) glucose3) movement / producing heat / keeps parts working properly4) burning5) carbon dioxide6) breathing it out7) plants produce oxygen during photosynthesis

Worksheet 20 Drugs and health.

body useful abuse illegal alcohol addict reactions alcoholic liver nervous lung hallucinate dangerously solvents

Worksheet 21 Germs and health.

1) inside our bodies2) under a microscope3) by producing poisonous waste chemicals4) smaller5) living cells

Worksheet 22 Fighting germs.

harmless defend skin breathed trachea swallowed stomach phagocytes eat antibodies vaccine medicines

Worksheet 23 Photosynthesis.

1) food2) light3) carbon dioxide and water4) chlorophyll5) respiration6) oxygen

Worksheet 24 Plant nutrition.

elements dissolved hair stem increase magnesium nitrogen root


Worksheet 25 Classification.

millions groups plants related chlorophyll food roots spores cones

Worksheet 26 Flowering plants.

seeds pollen female pollen insects nectar scented coloured join ovules fruit disperse

Worksheet 27 Animals without backbones (1).

1) vertebrates 2) invertebrates 3) tentacles 4) tapeworm 5) segments 6) snail 7) spines

Worksheet 28 Animals without backbones (2).

1) arthropods 2) insect 3) six, four 4) eight 5) sting 6) crustaceans 7) shrimps 8) segments

Worksheet 29 Animals with backbones.

internal fish reptiles amphibians moist birds feathers wings mammals hair milk

Worksheet 30 Variation.

1) variation2) continuous and discontinuous3) height / mass / hand size / intelligence etc.4) genes / instructions, environment / surroundings5) ovum6) growth7) minerals / nutrients

Worksheet 31 Selective breeding.

changed features useful pigeons ancestor fastest generations nature adapted

Worksheet 32 Living organisms and their habitats.

Exercise 1 Organism Habitat

fox ocean

dolphin jungle

monkey woodland

stickleback meadow

buttercup pond

Exercise 2 1) habitat 2) adaptation 3) waterproof 4) environment 5) water

Worksheet 33 Adapting to changes in habitats.

Exercise 1 nocturnal migrate hibernate seasonsExercise 2 changing desert behaviour food nocturnal adapt fat energy temperature

Property Solids Liquids GasesDensity (heavy or light) High density

(heavy)High density Low density

(light)How easy are they to compress(squash)?

Hard Hard Easy

Do they flow? No Yes Yes

Do they keep the same shape? Yes No No

Do they keep the same volume? Yes Yes No


Worksheet 34 Food chains and pyramids of numbers.

plants animals preyed predators prey greater food fewer

Worksheet 35 Food webs.

PLANTS HERBIVORES CARNIVORESpondweed tadpole water beetlealgae water snail small fishtree leaves water louse newt

large fishgrebe

large fish, grebe tadpole, water snail, water louse water louse

Worksheet 36 Poisoned food chains.

Exercise 1 1) pesticides 2) chains 3) pollute 4) biological controlExercise 2 5,000

Worksheet 37 Populations.

Exercise 1 grow food greater die prey killed survive size competitorsExercise 2 1) population 2) two 3) deaths

Worksheet 38 Solids, liquids and gases.

Worksheet 39 Changes of state.

DIFFUSION A solid changing to a liquid.

ICE The spreading out of particles.

MELTING The solid state of water.

STATE OF MATTER A solid, liquid or gas.

EVAPORATION A gas changing to a liquid.

CONDENSING A liquid changing to a gas.


Worksheet 40 Elements.

1) element 2) atom 3) nucleus 4) negative positive 5) protons 6) hydrogen

Worksheet 41 The periodic table.

properties protons hydrogen oxygen reactive magnetic halogens noble two

Worksheet 42 Compounds.

Exercise 1 C oxygen NaCl

Exercise 2 chemical physical chemical physical

Worksheet 43 Separating mixtures.

Filtration water sand paper

Distillation water evaporates flask

Chromatography paper speeds

Mixture Separating methodmuddy water distillationcopper sulphate solution filtrationpeas and sand magnetic attractioniron filings and sawdust sieving

Worksheet 44 Metals and non-metals.

Exercise 1 iron – metal bromine – non-metal copper – metal sulphur – non-metal

Exercise 2 1) mercury 2) carbon / graphite 3) magnetic 4) malleable

Worksheet 45 Changes of state.

1) gas 2) ethanol 3) sulphur 4) 119 °C 5) oxygen 6) ethanol

Worksheet 46 Solubility.

Exercise 1 dissolves solvent remover gloss spirit solutes

Exercise 2 1) dissolve 2) saturated 3) more 4) less

Worksheet 47 Expansion.

expand contract vibrate apart buckle snap thermometer scale

Worksheet 48 Rocks and weathering.

1) weathering 2) rain 3) sand 4) contraction 5) freezes

103

Worksheet 49 The rock cycle.

sediments transported layers compressed mudstone metamorphic magmaeruptions igneous

Worksheet 50 Types of rock.

1) molten magma that has cooled down2) slowly3) layers of sediment4) strata5) crumble6) changed7) marble

Worksheet 51 Chemical reactions.

Exercise 1 1) equal 2) properties 3) heat 4) reverse

Exercise 2 ELEMENTS The chemicals that are made.

PRODUCTS The simplest substances.

COMPOUND Starting chemicals.

REACTANTS Elements joined together.

Worksheet 52 Types of chemical reaction.

Exercise 1 1) join 2) breaks 3) oxygen

Exercise 2 1) synthesis 2) decomposition 3) oxidation

Worksheet 53 Burning.

1) oxygen 2) carbon dioxide 3) energy/heat/light 4) hydrogen 5) splint 6) fuel 7) air/oxygen 8) heat 9) air/oxygen

Worksheet 54 Products from chemical reactions.

1) chemical reactions 2) metal 3) reactive 4) mixture 5) polymers

Worksheet 55 Harmful chemical reactions.

corrodes reactive rusting water coating air paint oxidised taste cool oxidation

Worksheet 56 Energy from chemical reactions.

1) exothermic 2) light 3) electrical 4) hydrogen 5) carbon dioxide 6) sulphur dioxide

Worksheet 57 Reactivity of metals.

1) potassium 2) gold 3) too reactive 4) magnesium 5) it is very unreactive 6) steam

Answers to exercises.


Worksheet 58 Displacement reactions.

Exercise 1 COPPER + SILVER NITRATE COPPER NITRATE + SILVER (colourless) (blue)

Copper is more reactive than silver therefore it displaces silver in the solution.

Exercise 2 iron + silver nitrate iron nitrate + silver

zinc + magnesium oxide no reaction

Worksheet 59 Acids and alkalis.

1) corrosive 2) metals 3) red, blue 4) strength 5) weak acid

Worksheet 60 Acids and metals.

1) copper 2) salt 3) faster 4) hydrogen 5) explosive 6) hydrogen 7) acid 8) salt 9) soluble 10) reactive

Worksheet 61 Acids and bases.

1) base 2) alkalis 3) hydroxide 4) salt 5) chloride 6) oxygen 7) carbon dioxide 8) fizz

Worksheet 62 Neutralisation.

excess hydrochloric indigestion alkali acidic bicarbonate vinegar rainlimestone powdered

Worksheet 63 Acid rain.

1) sulphur dioxide 2) oil and coal 3) electricity 4) water droplets 5) die 6) minerals 7) metals 8) limestone

Worksheet 64 Electric current and voltage.

current voltmeter twice brighter positive flow

Worksheet 65 Series and parallel circuits.

Bulbs in series small resistance ammeter dimmer

Bulbs in parallel voltage larger easier bright batteries

Exercise 2 1) go out 2) larger brighter 3) B 4) 4

Worksheet 66 Electrical resistance.

filament current resistance heat light copper ohm thicker high lightsvolume resistance short

Worksheet 67 Magnets.

Exercise 1 1) attract 2) repel 3) repelExercise 2 A and C


Worksheet 68 Electromagnets.

1) weak magnetic field2) increasing the current, winding the wire into a coil, placing an iron bar inside the coil3) a coil of wire4) an iron bar placed inside a solenoid5) electric bells and relays6) steel

Worksheet 69 Uses of electromagnets.

An electric bell. switch coil arm gong contacts touch

Sorting scrap metal steel electric on off

Electromagnetic switches relay small input lever contacts output

Worksheet 70 Speed.

Exercise 1 1) 10 m/s 2) 120 km/h 3) 10 mph 4) 50 mph

Exercise 2 1) S × T = 40 mph × 3h = 120 miles

2) D = 200m = 20s S 10m/s

Worksheet 71 Force and movement.

1) unbalanced, accelerate 2) balanced, travel at a steady speed 3) unbalanced, slow down 4) balanced, move

Worksheet 72 Friction.

friction slip rim air resistance heat reduced faster

Worksheet 73 Turning forces.

1) pivot 2) lever 3) turning force 4) crowbar 5) longer

Worksheet 74 Moments.

Problem 1 anticlockwise moment = 20N × 3m = 60Nm clockwise moment = 40N × 2m = 80Nm

Therefore the beam will rotate in a clockwise direction.

Problem 2 anticlockwise moment = 40N × 3m = 120Nm clockwise moment = 60N × 2m = 120Nm

Therefore the beam will stay balanced.

Worksheet 75 Pressure.

1) 80,000N/m2 2) 2,500,000N/m2 3) 140N

Item of clothing In white light In red light In green light In blue light

white shirt white red green blue

red tie red red black black

blue jeans blue black black blue

green belt green black green black


Worksheet 76 Reflection.

1) luminous 2) torch, candle, glow worm, Sun, firework 3) reflection

4) diagrams are drawn to show that the angle of reflection is equal to the angle of incidence

Worksheet 77 Refraction of light.

1) medium 2) refraction 3) slowly 4) speed light rays traced back to where the coin appears to be

Worksheet 78 The spectrum.

1) prism 2) spectrum 3) dispersion 4) red 5) violet

only the red light passes through the red filter but it does not pass through the blue filter.

Worksheet 79 Coloured objects in coloured lights.

Worksheet 80 Hearing.

Part of ear Description

ear drum a tube that carries sound waves to the ear drum

ear canal a tight sheet of skin that vibrates when sound waves hit it

semi-circular canals sends nerve messages to the brain

auditory nerve contain fluid that swirls around when the head moves – gives balance

ear bones contains the sense cells that detect vibrations inside the ear

cochlea pass the vibrations from the ear drum to the cochlea

Worksheet 81 Sound.

Exercise 1 1) vibrating 2) waves 3) amplitude 4) frequency 5) higher 6) lower

Exercise 2 HIGH PITCH AND QUIET = C HIGH PITCH AND LOUD = A

LOW PITCH AND QUIET = D LOW PITCH AND LOUD = B


Worksheet 82 Comparing light and sound.

1) faster 2) transparent 3) see, hear 4) medium 5) sound 6) light 7) water carries sound better than air

Worksheet 83 Day and night.

axis day stars rotation towards away East West morning low highest

Worksheet 84 The seasons.

1) orbit2) complete one orbit of the Sun3) tilted towards the Sun4) away from

5) Summer 6) Summer 7) Spring, Autumn

Worksheet 85 The solar system.

1) Venus 2) Jupiter 3) longer 4) Mars 5) Mercury and Venus 6) Sun 7) Saturn

Worksheet 86 Satellites.

force gravity satellite Moon anticlockwise orbit full speed Earthtelescope atmosphere

Worksheet 87 The Moon and its phases.

1) phases 2) new 3) full 4) smaller 5) six 6) smaller

Worksheet 88 Energy resources.

1) fossil fuels 2) non-renewable 3) renewable 4) plants and animals 5) weather 6) expensive

Worksheet 89 The Sun and energy resources.

1) plants trap light energy during photosynthesis and store it in food2) dead plants and animals3) solar panels4) heat

Worksheet 90 Generating electricity.

1) turn2) generator3) steam4) coal5) only about one third of the chemical energy inside the coal is changed into electrical energy6) moving water7) run out


Worksheet 91 Energy transfer.

2) GRAVITATIONAL KINETIC

3) CHEMICAL HEAT + LIGHT

4) LIGHT ELECTRICAL

5) CHEMICAL HEAT KINETIC

6) KINETIC SOUND

Worksheet 92 Conservation of energy.

1) 10 units converted into light energy = 10% efficient

2) 80 units lost to the air = 20% efficient

3) 30 units converted into kinetic energy = 30% efficient

4) The diesel engine is a more efficient energy convertor.

KS3 Science Revision Worksheets Standard Edition · 2020. 3. 19. · KS3 Science Revision...

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Transcript of KS3 Science Revision Worksheets Standard Edition · 2020. 3. 19. · KS3 Science Revision...