SCIENCE -...
Transcript of SCIENCE -...
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SCIENCE: YEAR 7 REVISION GUIDE—BIOLOGY SECTION
Science Department
This Revision Guide will be generated as the year progresses. Each topic is
covered with both ‘key fact’ sheets, a question sheet and a suggested revision
method.
The question sheet is designed to test your revision of the key facts and see if
the information has sunk in. Just answering the questions is not an effective
revision method.
You will be given a set of sheets for each topic as you cover them in lessons.
The revision sheets will help you to revise for the end of unit test and your
school entrance exams at the end of year 8.
You will be given one hard copy to store in this folder but replacements can
be found online in the Student and Parent Portal section of the school
website. You are allowed to print as many copies as you like for your own
use.
We hope that they will be useful.
Good Luck
The Science Department
Photosynthesis
The process by which plants make their own food (glucose) using light energy.
Word Equation =
Necessary Conditions = Light and Chlorophyll (Chemical used to convert light energy)
Leaves are main area in which photosynthesis happens. Why?
Proving Photosynthesis has occurred
Test for starch – Plants store glucose as starch because it is insoluble. If a plant has been
photosynthesising it will have produced starch.
Proving Light is necessary for Photosynthesis
Destarch plant by placing in dark for 24 hours. Expose half of a leaf to light and cover half with pa-
per. Test for starch 24 hours later and observe that area exposed to light turns black (starch present)
and area covered remains brown (starch not present).
Proving Carbon Dioxide is necessary for Photosynthesis
Destarch plant by placing in dark for 24 hours. Cover one leaf in plastic
bag containing soda-lime (absorbs Carbon Dioxide from atmosphere).
Test for starch after 24 hours. Brown colour should indicate lack of
photosynthesis.
Carbon Dioxide + Water Glucose + Oxygen
Test for starch:
1. Boil leaf in water to remove waxy cuticle
(to allow Iodine Solution to penetrate leaf)
2. Place leaf in boiling ethanol
(To dissolve chlorophyll so that stain shows up)
3. Drop Iodine Solution on leaf
(If turns from brown to black, starch is present).
Photosynthesis, Respiration and Balance Between the Two
Respiration
Respiration is the release of energy from glucose in living cells to enable life processes.
Word Equation =
Respiration occurs in every living cell
Sometimes called Aerobic Respiration which means it uses Oxygen from the air.
Proving that Carbon Dioxide is produced during Respiration
Testing carbon dioxide is present involves bubbling the gas through lime water. If it turns
milky white then carbon dioxide is present.
Proving that Water is produced during Respiration
Exhale onto cold surface to collect condensation. Add anhydrous copper sulphate to
liquid collected. If it turns from white blue water is present. Or use anhydrous cobalt chloride paper, if water is present turns from blue pink.
Balance Between the Two
Plants photosynthesise and respire.
Plants respire 24 hours a day (steadily because they do not move about)
Plants photosynthesise during the day or when light is present
Think of these different scenarios with an indicator (hydrogencarbonate) which shows the levels of CO2 .
What changes will occur?
Photosynthesis removes Carbon Dioxide from the surroundings.
Respiration adds Carbon Dioxide to the surroundings.
Respiration is NOT breathing. Think of it as burning glucose to release its energy.
(Remember burning needs oxygen to happen)
Glucose + Oxygen Carbon Dioxide + Water + Energy
Possible Revision Method—The Model Room
Draw a picture of a room below. Decide on a logical order for each memory trigger.
Then associate it with a fact to be learned on the process of photosynthesis.
Can be adapted, and you can walk around a room, to help you with your associations
(good for kinaesthetic learners)
For example:
Plant in photo—name of
process photosynthesis
Sunlight in picture—hits
plants and starts reaction
CO2 Clock—Carbon dioxide and water needed for photosynthesis.
Green in picture—
represents the chlorophyll.
Sofa—represents the oxygen and
glucose that is produced.
Possible Revision Method—Flow charts
Write down the steps of a process (procedure) as keywords or short phrases the show
the connections by using arrows.
A good technique to learn the method for testing for starch.
STEP 1:____________________
___________________________
___________________________
STEP 2:____________________
___________________________
___________________________
STEP 3:____________________
___________________________
___________________________
STEP 4:____________________
___________________________
___________________________
STEP 5:____________________
___________________________
___________________________
STEP 6:____________________
___________________________
___________________________
Questions
If you have revised the previous sheets effectively you should be able to answer the following
questions without difficulty.
1. Complete the following word equation.
2. Name two necessary conditions for photosynthesis to occur.
3. When testing for starch why do you boil the leaf in water first?
4. What colour change do you witness in Iodine Solution when starch is present?
5. How can you prove that light is necessary for Photosynthesis?
6. Why do you need to destarch a plant before testing to see if photosynthesis has occurred?
7. What substance removes Carbon Dioxide from the surroundings?
8. What fuel does respiration require in order to produce energy?
9. Where does respiration occur?
10. What gas is given off during respiration and how can you prove this?
11. What gas would be detected by a probe if placed near a plant at midnight? Why?
12. Why do levels of photosynthesis fluctuate during a 24 hour period?
13. Why do levels of respiration stay constant in plants during a 24 hour period?
Carbon Dioxide + ______________ _________________ + Oxygen
For extra info or help with revision use the following pages in the KS3 CGP The Study Guide
Photosynthesis pg. 19
Respiration pg. 4
Microscopes and Cells
The Microscope
Used to view things too
small for the naked eye.
Consists of lenses of
different magnification to
make things appear bigger in
the viewfinder.
Eye Piece x10 magnification
Objective Lenses x10, x20
and x40.
Magnification and Estimation
It is often necessary to estimate the size of an organism
from an image produced by a microscope.
You need to know the magnification of the image and
use a ruler to measure the image carefully.
Magnification x 500
Making a temporary slide
Specimens viewed down a microscope are usually placed and possibly stained (to
enable parts of the cell to be seen) on a glass slide to help isolate the specimen.
Revise the process of producing the slide
If an eye piece with magnification x20 is used and an objective lens with a magnification of x40 the total
magnification is x800 (20 x 40).
1. Place specimen on slide.
2. Place a drop of stain over
specimen.
3. Lower a cover slip over stain
and specimen edge first, using a
mounted needle.
Cells
The building blocks of all living organisms. They combine to form tissue which
combines to form organs.
Tissues are lots of cells with the same job.
Organs are tissues cooperating to perform a function.
Organ Systems are organs with cooperate to perform a life function.
Organelles and their functions.
Found in both Animal and Plant
Cell Membrane – Controls what enters and exits the cell
Cytoplasm – Where chemical reactions take place within the cell
Nucleus – Contains DNA which controls the functions taking place in the cell.
Mitochondria – the site of respiration in cells.
Found only in Plants
Cell Wall – Provides structure and support to the cell. Rigidity. Made of Cellulose.
Chloroplast – Contains Chlorophyll which helps photosynthesis take place.
Vacuole – Contains cell sap which helps maintain the shape of the cell.
Specialised Cells
Sperm Cell
Small cell which contains half
the genetic information in
the nucleus in its head. Has
a tail for swimming to make
its way to fertilise the ovum.
Root Hair Cell
Cell within the roots of a
plant with projections which
help increase surface area to
help absorb lots of water.
Red Blood Cell
Carries oxygen around the
body. Has a dimple to in-
crease the surface area for
oxygen to bind to the cell.
Possible Revision Method—Mind Map
Mind maps can be used to represent key information. When designing a mind map you
should look to connect ideas, using keywords and including diagrams to help you
visualise a concept.
CELLS
Questions
If you have revised the previous sheets effectively you should be able to answer the following
questions without difficulty.
1. What do microscopes enable scientists to do?
2. Which part of the microscope is responsible for magnifying the image?
3. Estimate the length of the head of the creature in the picture on the first page.
4. Why do you sometimes need to stain specimens?
5. Why do you think a cover slip is placed over the specimen?
6. What is a cell?
7. What do cells combine to form?
8. Name three organelles not present in an animal cell?
9. What does the chloroplast do?
10. What is the nucleus for?
11. What is the job of the cell membrane?
12. What is the cell wall made from?
13. What is the main specialised feature of a sperm cell?
14. Why do root hair cells have small projections coming out of them?
15. Why does a red blood cell have a dimple?
For extra info or help with revision use the following pages in the KS3 CGP The Study Guide
The Microscope pg. 1
Cells & Cell Organisation pg. 2 & 3
Health, Nutrition and Digestion
Health
Microbes and Disease
Microorganisms come in different
varieties and sizes.
From largest to smallest
Protozoan
Bacteria
Virus
They cause disease in living
organisms e.g. Smallpox or influenza.
Pathogen = Disease causing microorganism
Host = Organism affected by pathogen
Protection form disease: Good levels of hygiene. Washing hands
Prevention of entry of microorganisms into body – Forming of scabs, wearing of plasters
White blood cells kill bacteria and viruses if unwanted in body Vaccination – prevention of infection
Nutrition
Good for Health Bad for health
Regular exercise Excessive eating
Balanced diet Poor diet
Vitamins Lack of exercise
Hydration Drug abuse
Excessive Alcohol intake
Part of diet Foods rich in substance Reason for needing it
Fats Meat, Dairy Source of energy, helps insulate body
Proteins Meat, Poultry, Nuts Cell repair and growth
Simple Carbohydrates Sweets, Chocolate Quick energy release
Complex Carbohydrates Bread, Pasta, Rice Slow energy release
Vitamins Vegetables and Fruit Improved cell function
Fibre Wholemeal bread, Fruit Aid food moving through digestive system.
Food Tests:
Starch: Adding Iodine solution to food. If starch is
present the colour change is from
red/brown blue/black
Sugar: Add Benedicts Reagent. If sugar is present a
Brick Red precipitate is formed in the reagent. Traces
of sugar cause green/yellow/orange colour.
Fats: Add one or two droplets of ethanol. Add this
ethanol to water. If a white suspension forms fats are present.
Digestion
The mechanical and chemical breakdown of large food molecules into smaller molecules which
can be easily absorbed into the blood.
Not to be confused with:
Ingestion – consumption of a substance
Egestion – removal of undigested food or faeces from gut (make sure to know the difference
between egestion and excretion)
Enzymes:
Produced in the various glands including the pancreas. They are mostly secreted into
the duodenum to be mixed with food and to chemically breakdown the food.
Different enzymes are produced for different substances (lock and key model).
e.g. Amylase in saliva is used to breakdown starches.
Can be denatured (stopped from working) if the pH or temperature is too high.
Benedicts Reagent
Possible Revision Method—Mind Map
Mind maps can be used to represent key information. When designing a mind map you
should look to connect ideas, using keywords and including diagrams to help you
visualise a concept.
Create a mind map on the different type of nutrients include food tests
Possible Revision Method—Flow charts
Write down the steps of a process (procedure) as keywords or short phrases the show
the connections by using arrows.
Use a blank piece of paper.
Create a flow chart on the digestive process
Attempt below.
Questions
If you have revised the previous sheets effectively you should be able to answer the following
questions without difficulty.
1. When does alcohol consumption become dangerous?
2. Name one factor that aids a healthy lifestyle.
3. Name three types of microorganism.
4. Which is the smallest in size?
5. Name two forms of defence against infection?
6. What is the difference between pathogen and host?
7. What is the role of fat in our diet?
8. Name a foodstuff that contains high levels of complex carbohydrates?
9. What is the difference between complex and simple carbohydrates?
10. What are proteins used for in our diet?
11. What is the test for starch in foods? Describe colour change.
12. What is the test for sugars in our diet? Describe colour change.
13. What is digestion?
14. Where is the first site of mechanical breakdown of food in the digestion process?
15. What is mixed with food in the duodenum?
16. Name one source of enzymes in the human body.
17. What can denature enzymes and stop them from working effectively?
For extra info or help with revision use the following pages in the KS3 CGP The Study Guide
Nutrition pg. 6 & 7
Digestion pg. 8 & 9
Health and Drugs pg. 17
Element = Substance consisting of one type of atom
Compound = Substance consisting of two or more different elements chemically combined
Mixture = Substance containing two or more elements or compounds that
have not been chemically joined.
Molecule = A groups of atoms chemically joined e.g. water H2O, oxygen O2
The Atom
Particle Theory As particles are heated they gain kinetic energy. As they are cooled they lose kinetic energy.
Elements Elements form the periodic table.
Metal Oxides are BASIC and SOLID
For example magnesium + oxygen magnesium oxide
Non-metal Oxides are ACIDIC and GASES
For example carbon + oxygen carbon dioxide
Elements, Compounds and Mixtures
Consists of three different units. Electrons (negatively charge and
whizzing around the outside), Protons (Positively charged and in the
nucleus.) and Neutrons (no charge and in nucleus).
Atoms combine to form compounds.
Name Symbol
Hydrogen H
Carbon C
Sulphur S
Iron Fe
Copper Cu
Sodium Na
Oxygen O
Nitrogen N
Calcium Ca
Helium He
Magnesium Mg
Potassium K
Non-metals Metals
Compounds
Compounds are formed when two or more elements combine.
Compounds have different properties to the elements that combine to make them.
Naming Compounds
1. –ide = Two elements joined together e.g. Iron + Sulphur Iron Sulphide
2. –ate = More than two elements joined together with oxygen being one of them
e.g. Copper + Sulphur + Oxygen Copper Sulphate
Class practical: Iron + Sulphur Iron Sulphide
Look at the observations made during this reaction.
Chemical Symbols
Chemical symbols are used to represent compounds. The numbers relate to how many atoms there
are in the compound.
Water has two Hydrogen atoms
Conservation of mass – The mass of the reactants equals the mass of the products. For example,
Magnesium gets heavier when heated in air because it chemically combines with oxygen to form
Magnesium oxide (Mg MgO).
Mixtures
Mixtures are two elements or compounds that are together but not chemically joined.
Dissolving is a good way to form a mixture.
Mixtures can be easily separated (See separating substances section when complete)
You need to recognise this reaction. It shows that a new substance is formed.
Before reaction Iron is magnetic. Iron Sulphide is not
and therefore proves a new substance has been formed.
H2O and one Oxygen atom
Possible Revision Method—Summary Cards
Summary Cards contain the most important details of a topic. You should try to create
a summary of the information, including key words, concepts and diagrams.
Su
mm
ary T
op
ic: E
lemen
ts, Com
pou
nds a
nd M
ixtures
Card
No
. __
__
____
__
Questions
If you have revised the previous sheets effectively you should be able to answer the following
questions without difficulty.
1. What three particles combine to form an atom?
2. What is the name given to the negatively charged particle in an atom?
3. Define an element.
4. Define a compound.
5. Define a mixture.
6. Draw diagrams to represent the particles in each of the states of matter below.
7. Where do you find non-metals on the periodic table?
8. Copper + Oxygen ___________________
9. Copper + Sulphur + Oxygen ____________________
10. Iron + Sulphur ___________________
11. How can you tell that a reaction is occurring (or has occurred) between Iron + Sulphur in
the production of Iron Sulphide? Give two reasons
12. How many Carbon atoms are there in a molecule of Glucose?
C6H12O6
Solid Liquid Gas
For extra info or help with revision use the following pages in the KS3 CGP The Study Guide
Atoms and Elements pg. 35
Periodic Table pg. 36
Compounds pg. 37
Naming Compounds pg. 38
Mixtures pg. 39
Making and Testing Gases & Gases in the Air
Hydrogen
Making Hydrogen
METAL + ACID SALT + HYDROGEN
MASH
Testing for Hydrogen
Using a lit splint the hydrogen should ignite with a
squeaky pop.
Oxygen
Making Oxygen
Thermally decompose (heat) potassium permanganate
Testing for Oxygen
Using a glowing splint plunge into oxygen and it should relight.
Carbon Dioxide
Making Carbon Dioxide
METAL CARBONATE + ACID WATER + SALT + CARBON DIOXIDE
MCAWSCD
Testing for Carbon Dioxide
Bubble carbon dioxide through limewater. Limewater turns
milky white.
Collecting Gas over water
If a gas needs to be collected it should be done over water as shown in diagram be-
low. (Learn the diagram!)
Gases in the Air
Air is a mixture of gases
It consists of different quantities of a variety of different gases
To prove the percentage of oxygen you can use the set up shown below. Heat the copper
filings between the syringes to form copper oxide and remove oxygen from the air within the
syringes. The syringe should read 100ml at the beginning and 79ml at the end thus showing ox-
ygen is 21% of air.
HEAT
Gas Percentage of
Air
Nitrogen 78%
Oxygen 21%
Carbon Dioxide 0.03%
Argon and other
trace gases Trace amounts
Possible Revision Method—Review Cards (Flash Cards)
Review Cards pose questions with long answers or facts on the back.
Flash Cards can be used to learn key words or definitions
SC
IEN
CE
: Mak
ing an
d Te
sting G
ases
Questio
n
Answ
er(s)
Questions
If you have revised the previous sheets effectively you should be able to answer the following
questions without difficulty.
1. How is Hydrogen made in a lab?
2. How do you test for Hydrogen?
3. How is Oxygen made in a lab?
4. Do you use a lit splint or glowing splint to test for oxygen?
5. What substance is used to test for carbon dioxide?
6. What change is seen in this substance if carbon dioxide is present?
7. Write the word equation for the production of carbon dioxide.
8. Write the word equation for the production of hydrogen.
9. Draw the diagram for the collection of gas over water.
10. Why does gas rise to the top of the test tube when being collected over water?
11. What is the percentage of Nitrogen in the atmosphere?
12. If 100cm3 of Air is passed over copper filings which are being heated. After several
minutes what will be the volume of air?
13. Why?
Fuels
Fuels react with oxygen to release energy. Most fuels contain hydrocarbons.
These are compounds of hydrogen and carbon only.
Complete Combustion: Complete combustion releases more energy than
incomplete combustion. It requires a plentiful supply
of air so that the elements in the fuel react fully with
oxygen.
The general equation for complete combustion is:
hydrocarbon + oxygen carbon dioxide + water
Incomplete Combustion:
Incomplete combustion occurs when the supply of air or oxygen is poor, resulting in carbon
monoxide being produced rather than carbon dioxide and producing some carbon (soot) which
has not be oxidised.
The general equation for incomplete combustion is:
hydrocarbon + oxygen carbon monoxide + water
or
Hydrocarbon + oxygen carbon + water
The Bunsen Burner
Air hole open
When the air
hole is open, air
is drawn into the
chimney, where
it mixes with the
natural gas. This
ensures complete
combustion.
Air hole closed
When the air hole is closed
the natural gas can only mix
with air at the mouth of the
chimney. Incomplete
combustion occurs as a
result. A yellow flame is
produced, which transfers
less heat energy than the
blue flame.
Questions
If you have revised the previous sheets effectively you should be able to answer the following
questions without difficulty.
1. How can you test that carbon dioxide gas was produced?
2. What is a test to determine that water is present?
Acids, Alkalis and Neutralisation
Acids
Have a low pH
Have a sour taste (tartaric acid used in toxic waste sweets!!)
Contain Hydrogen and are used to make Hydrogen in reactions with metals.
Make Carbon Dioxide in reactions with carbonates.
Can react to produce salts – Hydrochloric Acid Chloride Salts, Nitric acid Nitrate
Salts, Sulphuric Acid Sulphate Salts etc.
Alkalis
Have a high pH
Soapy texture (often used in cleaning fluids)
Alkalis are soluble bases (bases which have dissolved)
All alkalis are bases but not all bases are alkalis.
Bases
Substances which can neutralise an acid.
When dissolved in water to form a solution are called alkalis
Usually metal oxides, hydroxides or carbonates e.g. Magnesium Oxide, Sodium
Hydroxide.
The pH Scale
Used to help identify the strength of an acid or base/alkali.
Universal Indicator is used to help show the pH by checking the colour
it turns against the colour chart.
If an acid is diluted its pH does not change significantly.
Neutralisation
When acids and alkalis are combined to form salts.
The salt contains the metal from the alkali and part of the acid molecule.
eg Sodium Hydroxide + Hydrochloric Acid Sodium Chloride + Water
The salt depends on the type of acid e.g. sulphuric acid forms
sulphate salts.
ACID + ALKALI SALT + WATER
The Reactions of Acids with Alkalis, Bases, Metal Carbonates and Metals
The Rules
Bases are metal oxides or metal hydroxides, e.g. iron oxide and calcium hydroxide.
Alkalis are bases which dissolve in water. They are always metal hydroxides, e.g.
potassium
hydroxide and sodium hydroxide.
Metals all conduct electricity. Lots of them have names ending in ‘-ium’ although
there are a few
non-metals which also end in ‘-ium’. They include metals with common names like
copper, lead and aluminium.
Metal Carbonates are all metals combined with carbonate groups, e.g. copper
carbonate, potassium carbonate and iron carbonate. They are also classified as bases
because they neutralise acids, but they react with acids in a different way to metal
oxides and metal hydroxides.
Acids all contain hydrogen. The three we need to know are hydrochloric acid,
sulphuric acid and nitric acid.
Hydrochloric acid reacts to form chloride salts
Sulphuric acid reacts to form sulphate salts
Nitric acid reacts to form nitrate salts.
The Rules II
Base + Acid Water + Salt (BAWS)
Acid + Alkali Water + Salt (AAWS)
Metal + Acid Salt + Hydrogen (MASH)
Metal Carbonate + Acid Water + Salt + Carbon Dioxide (MCAWSCD)
A salt is a metal sulphate, metal chloride or metal nitrate.
Hydrochloric acid makes chloride salts
Sulphuric acid makes sulphate salts
Nitric acid makes nitrate salts Phosphoric acid makes phosphate salts
Neutralisation Reactions
1. Sulphuric Acid + Copper oxide
2. Nitric Acid + Iron carbonate
3. Hydrochloric acid + sodium hydroxide
4. Sulphuric acid + Zinc
5. Acetic acid + aluminium
6. _____________ + ____________ lead nitrate + carbon dioxide + water
7. ______________ + Magnesium Magnesium chloride + _____________
8. Nitric acid + ____________ Calcium __________ + water
9. Zinc oxide + Nitric acid
10. Magnesium hydroxide + sulphuric acid
11. Copper + hydrochloric acid
Possible Revision Method—Review Cards (Flash Cards)
Review Cards pose questions with long answers or facts on the back.
Flash Cards can be used to learn key words or definitions
SC
IEN
CE
: Neutralisatio
n Salt N
ames
Questio
n
Answ
er(s)
Questions
If you have revised the previous sheets effectively you should be able to answer the following
questions without difficulty.
1. Is an acid’s pH low or high?
2. What chemical element do all acids contain?
3. Name a household acid.
4. What chemical compound do acids always produce in the reactions you have learnt?
5. What acid produces chloride salts?
6. What acid produces sulphate salts?
7. What acid produces nitrate salts?
8. What is an alkali?
9. Is an alkali’s pH high or low?
10. Name a household alkali.
11. Give two examples of bases.
12. What is the pH scale used for?
13. How do you find the pH of a chemical? (include all detail!) [3 marks]
14. Does an acid’s pH change much if water is added to it?
15. What determines which salt is produced in a neutralisation reaction?
For extra info or help with revision use the following pages in the KS3 CGP The Study Guide
Acids and Alkalis pg. 52
Neutralisation Reactions pg. 53
Reaction of Metals with Acids pg. 55
Reaction of Oxides with Acids pg. 56
Energy
Types of Energy
Energy can be found in several different forms or types. You need to remember 8!
ENERGY Chemical
Strain
(Elastic)
Kinetic
Light
Gravitational
Potential
Heat Electrical
Sound
Law of Conservation of Energy
Microphone: Sound Electrical
Fire: Chemical (wood) Heat + Light
Skydiver: Gravitational Potential (In Plane) Kinetic (Falling)
Renewable and Non-Renewable Energy Sources
Non-Renewable
An energy resource that will not be replenished in one’s lifetime.
Fossil Fuels are prime examples of non-renewable energy sources.
Oil (Chemical Heat + Light)
Coal (Chemical Heat + Light)
Gas (Chemical Heat + Light)
All fossil fuels originally derived their energy from the sun when the organisms that
formed them were alive.
Fossil Fuels will run out. It takes millions of years for them to be made.
They are all energy in the form of chemical energy.
Renewable
An energy resource that will be replenished in one’s lifetime.
Sometimes more expensive to initiate but more kind on the environment
Examples include: Solar (light electrical or heat), Wind (kinetic electrical), Tid-
al (kinetic Electrical), Hydroelectric (Kinetic Electrical)
Thermal (Heat) Energy
Thermal energy is one of the most common forms of energy. It can transfer from
one place to another in a variety of different ways.
Conduction transfers heat through solids.
Convection transfers heat through convection currents in liquids and gases.
Radiation can pass through a vacuum.
Convection Current
Possible Revision Method—Create a Mnemonic
An mnemonic is a made up rhyme to help you memorise lists of information.
Mnemonic—Energy Types
Possible Revision Method—Review Cards (Flash Cards)
Review Cards pose questions with long answers or facts on the back.
Flash Cards can be used to learn key words or definitions
Question
SCIENCE: Heat Transfers
Answer(s)
Questions
If you have revised the previous sheets effectively you should be able to answer the following
questions without difficulty.
1. Name eight different types of energy.
2. Which type of energy is gained when you climb a ladder?
3. Which type of energy is stored in our food?
4. What is the law of conservation of energy?
5. What energy transfer occurs in a guitar amplifier?
6. What energy transfer occurs when BBQ fuel burns?
7. What energy transfers occur in a Hydroelectric Power plant? (more than those stated)
8. Name three types of fossil fuel.
9. Name three types of renewable energy source.
10. What is a drawback of renewable energy?
11. What is a positive of renewable energy?
12. Why are fossil fuels not a good source of energy for the future?
13. Name the three methods by which thermal energy can be transferred.
14. What happens to heat energy during convection?
15. How do radiators heat a room effectively?
16. Is radiator a good name for a radiator?
For extra info or help with revision use the following pages in the KS3 CGP The Study Guide
Energy Transfers pg. 66 & 67
Heat Transfer pg. 68
Conservation of Energy pg. 69
Energy Resources pg. 70
Generating Electricity pg. 71
Light & Sound
Light
Part of the electromagnetic spectrum (Visible spectrum)
Travels in strait lines
Reflection
Angle of incidence (i) = Angle of reflection (r)
Refraction
Refraction is when light changes direction due to a change of speed as it enters from
one medium to another.
When light slows down it moves towards the normal.
When light speeds up it moves away from the normal.
The normal is drawn perpendicular (at right angles) to the surface of the new medium.
Dispersion
White light consists of a combination of the different colours of the rainbow.
White light must be refracted twice in a prism to disperse into its different colours
(the spectrum).
Diagrams: You should be able to draw basic diagrams of
Reflection, Refraction and Dispersion.
Knowing how to draw them should help you remember how the light is affected and how it moves.
The angle of reflection and incidence are
measured between the ray and the normal,
not the ray and the reflective surface.
Sound
Made by vibrating matter
Travels much slower than light (speed of sound in air is 330m/s)
Frequency and Amplitude are two different measurements taken from sound
Frequency
The number of vibrations in one second.
How high or low (pitch) the sound is—high
frequency equates a high pitch; a low frequency
equates a low pitch.
Stringed instrument:
To change frequency—shorten string, tighten string,
make string thinner
Drum:
To change frequency—tighten skin, make skin thinner
Amplitude
Changes the volume of the sound
Stringed Instrument:
To change amplitude—pluck strings harder.
Drum:
To change amplitude— hit the skin harder.
Sound travels in Waves
Two types of wave: Transverse and Longitudinal
The shorter the wavelength (see diagram below) the higher the frequency.
These are graphs of sound waves—sound waves themselves are longitudinal.
Sound travelling through different mediums
Light travels faster through solids than liquids and gases. This is because the particles are closer
together and thus pass vibration on more efficiently.
Echoes: occur when sound reflects of a
surface and travels back to where it was
made.
Used to measure distances. For example,
sonar or echolocation
Possible Revision Method—Audio
For auditory learners, try reading the information aloud, record yourself reciting key facts,
use video clips, put key facts into a well known tune or talk about your learning to
others.
Possible Revision Method—Summary Cards
Summary Cards contain the most important details of a topic. You should try to create
a summary of the information, including key words, concepts and diagrams.
Su
mm
ary T
op
ic: Ligh
t—Refra
ction, R
eflection a
nd D
ispersion
Card
No
. ________
Questions
If you have revised the previous sheets effectively you should be able to answer the following
questions without difficulty.
1. What is unusual about how light travels?
2. Does light travel faster or slower than sound in air?
3. When light rays hit a mirror what process do they undergo?
4. What is the relationship between the angle of incidence and the angle of reflection?
5. Where do you draw the normal on a light ray diagram?
6. What happens when light travels from glass to air?
7. If light slows down when travelling from one medium to another does it bend towards or
away from the normal?
8. What happens when light rays are shone through a prism and refracted twice?
9. Draw diagrams of Reflection, Refraction and Dispersion.
10. What is it that makes sound?
11. What is frequency?
12. What is amplitude?
13. What is the relationship between wavelength and frequency?
14. How do you change the frequency of sounds coming from a guitar?
15. How do you change the amplitude of sounds coming from a drum?
16. What is an echo and how can it be useful?
17. Does sound travel faster in water or iron? Why?
For extra info or help with revision use the following pages in the KS3 CGP The Study Guide
Light Waves pg. 87
Reflection and Refraction pg. 88
How We See pg. 89
Colour pg. 90
Sound pg. 91
Hearing pg. 92
Density, Pressure and Speed Calculations
Density
Mass per unit of volume
Measured in g/cm3 or kg/m3
Density (g/cm3) = Mass (g) / Volume (cm3)
Mass (g) = Density (g/cm3) x Volume (cm3)
Volume (cm3) = Mass (g) / Density (g/cm3)
Pressure
Force per unit of area
Measured in N/m2 or N/cm2
Sometimes measured in Pascals. 1 pascal = 1N/m2
Pressure (N/m2) = Force (N) / Area (cm2)
Force (N) = Pressure (N/cm2) x Area (cm2)
Area (cm2) = Force (N) / Pressure (N/cm2)
Speed
Distance per unit of time
Measured in m/s or km/h
Speed (m/s) = Distance (m) / Time (s)
Distance (m) = Speed (m/s) x Time (s)
Time (s) = Distance (m) / Speed (m/s)
D = M/V
M = D x V
V = M/D
P = F/A
F = P x A
A = F/P
S = D/T
D = S x T
T = D/S
Conversions
Please be careful that you convert units appropriately and effectively. Remember the following:
1 metre = 100 cm
1 kilometre = 1000 m
1 m2 = 10000 cm2
1 m3 = 1000000 cm3
1 litre = 1000 ml
Questions
If you have revised the previous sheets effectively you should be able to answer the following
questions without difficulty.
1. What is a more unusual unit used for pressure?
2. Without looking on the previous page. Write the full word equations (with units) for all
3 calculations relating to Density.
3. Without looking on the previous page. Write the full word equations (with units) for all
3 calculations relating to Pressure.
4. Without looking on the previous page. Write the full word equations (with units) for all
3 calculations relating to Speed.
5. How many metres in 1.53 km?
6. How many litres is 897ml?
7. How many metres is 1240cm?
8. What is the volume of a stone that has a mass of 120g and a density of 4g/cm3?
9. Mo Farah took 13mins 40s to complete the 5000m race at the London 2012 Olympics.
How fast was he
running on average?
10. How much pressure does the stiletto with an area of 1.4cm2 exert on the floor when a
woman weighing 500N stands on one leg?
11. What is the density of grandma’s fruit cake? It is a cuboid shape with a height of 10cm,
width of 15cm and length of 30cm and when placed on the scales measures in at 1kg.
12. Yohan Blake was clocked running 100m in training at an average of 40km/h. Would he beat
Usain Bolt’s 100m World record of 9.58s?
For extra info or help with revision use the following pages in the KS3 CGP The Study Guide
Speed pg. 77
Pressure pg. 84