Junior Cert Revision 2

Solids• Expansion can damage railway lines

Heat Transfer

Conduction-Transfer

byvibrations

Radiation-Transfer by

Electro-magnetic wave

Convection- Hot air

risingcarrying

theheat up with it.

Water as a Poor Conductor

HEAT

The ice does not melt as the water is a terrible conductor and convection only works up.

Metal Gauze

ICE

Test Tube of water

Example of convection currentSea Breezes

HOT LAND

WARM SEA

Day – On Shore

Heating a solidHeating a solid

Temperature

Time

Melting point

Boiling point

Heating a solidTemperature

Time

Boiling point

Melting point

Melting

Solid

Boiling

Liquid

GasHeat raises

temperature

Latent Heat Only

Photosynthesis

water

Carbon dioxide

Energy from sunlight, with chlorophyll as a

catalyst, is used to combine CO2 and H2O to

form glucose and release O2

chlorophyll

oxygen

glucose

Water + Carbon Dioxide Glucose + Oxygen

Sunlight

Chlorophyll

Water goes up the Xylem

From root To leaf then

Transpire

Sugar madeIn the leaf

Goes down The Phloem

Properties of an Acid

· Tastes sour· Turns blue litmus paper red

· Has a pH of less than 7· Lemon juice and vinegar are good examples.

ACID

Properties of a Base · Turns litmus paper blue· Has a pH greater than 7· taste bitter and have a slippery feel

· Bases that are soluble (dissolve in water) are called alkalis

Most hand soaps and drain cleaners are bases

p Hp H

A measure of how acidic something is

A measure of how acidic something is

T h e p H S c a l eT h e p H S c a l e

• A N e u t r a l s o l u t i o n h a s a p H o f 7 .

• A n A c i d i c s o l u t i o n h a s a p H b e l o w 7 .

• A B a s i c s o l u t i o n h a s a

p H a b o v e 7 .

• A N e u t r a l s o l u t i o n h a s a p H o f 7 .

• A n A c i d i c s o l u t i o n h a s a p H b e l o w 7 .

• A B a s i c s o l u t i o n h a s a

p H a b o v e 7 .

IndicatorsThese are chemicals that change colour in the presence of an acid or a base.

We get them from Plants.

Adding acid to carbonatesCalcium Carbonate + Hydrochloric AcidCalcium Chloride+water+Carbon

Dioxide

CaCO3 + 2HCl CaCl2 + H2O +CO2

The equation must be balanced

CarbonDioxide

Electromagnet• A soft iron rod has

no magnetic field• When current flows

in the wire the soft iron becomes magnetised so a magnetic field is detected by the plotting compasses.

Positive and Negative Charge

Same charges repel

Positive and Negative Charge

Unlike charges attract

Conductors and Insulators

A conductor is a substance through which electric charge flows readily. An insulator is a substance that strongly resists the flow of electric charge.

Conductor

insulator

Effect of Van De Graaf

• Hair is pushed apart as all the electrons on the hair repel each other.

Water Treatment

Screening - Clean water passes through the screen and large objects do not

Sedimentation - Aluminium Sulphate is added allowed to settle.

Filtration – passes through sandAdd chlorine to kill

bacteria and flourine

Hard and soft water• Add soap and mix

Add Soap solution

Add Soap solutionHard

WaterFew

BubblesOily scum

Soft WaterLots of

Bubbles

Where hard water comes fromAcid Rain

Limestone

Water dissolves the limestone (Calcium Carbonate) and the calcium

ions make the water hard

Water that runs off straight to

rivers and lakes is soft water

Sound is Energy

• Sound is caused by the movement of the medium it is travelling in

• Anything that vibrates makes sound

Compressions

in the medium

Loudspeaker

Sound in Space• Sound needs a medium (Air, String and

even water)• We can prove this by sucking all the air

out of a jar with an electric bell inside

When we have sucked out all the air from the jar we can not hear the electric bell

Glass bell jar

Vacuum

Electric Bell

Echo

• A reflected sound wave

If sound takes 2s the get to the cliff and return and sound travels at 340m/s.

Distance = Speed x time=340x2

=680m,

but how far away is the cliff face?

1) Amplitude – this is height of the wave.

2) Wavelength () – this is the distance between two corresponding points on the wave and is measured in metres:

3) Frequency – this is how many waves pass by every second and is measured in Hertz (Hz)

Crest

Trough

Light on cards goes through if the cards are lined up. This also proves light

travels in straight lines

Reflection

Incident ray

Normal

Reflected ray

Angle of incidence

Angle of reflection

Flat Mirror

Angle of incidence = Angle of reflection

Refraction

Fisherman use a trident as light is bent at the surface

The fisherman sees the fish and tries to spear it

Focal Point

Focal Point

Lenses Two types of lenses

Converging Lens Diverging Lens

Dispersion

• Breaking up of white light into it’s colours

Primary and secondary colours

Ecology…• Study of the relationship between

plants and animals and their environment

Levels of organization - Terms

• Organism – living thing• Population – one species live in one place at one

time• Community – All populations (diff. species) that

live in a HABITAT.

Connections

Primary Producer Primary

Consumer Secondary Consumer

Top of the food chain

• Carnivore eats other animals

• Herbivore eats plants

• Omnivore eats plants and animals

• Adaptation is the development of special characteristics by plants or animals to suit a particular environment.

Adaptation to environment

Parts of a Flowering Plant

Male Parts

Anther

Filament

Together called the STAMEN

Female Parts

Stigma

Style

Ovule

Ovary

Together called the CARPEL

PollenPollen is produced in the ANTHER

The anther explodes and pollen just goes everywhere

Some of the pollen sticks on the STIGMA

The pollen goes down a small tube to the EGG

There are lots of eggs in most plant ovaries.

PollenSexual reproduction is where two different cells meet

Sex cells are called GAMETES

Pollen is the male gamete

The female gamete is the EGG

When the pollen and egg meet this is called FERTILISATION

Ways to Scatter Pollen

Wind Insect

Fertilisation

When the male gamete POLLEN

Gets inside the female gamete or EGG

They form a ZYGOTE

This is the first cell of a new plant

Seed or Fruit Formation

Testa

Food Supply(OIL and STARCH)

Plumule

RadicleThe two together make the

EMBRYO

Seed Dispersal

The carrying of the seed (and its surrounding fruit) as far away from the parent plant as possible

WIND

Dandelion

Sycamore

ANIMALS

EATEN

Berries

STICKY

Thistles

Asexual Reproduction

A plant produces another plant without involving a second plant

No gamete cells are used.

The plant sends out runners

Inside of the eye

pupil

iris

lens

optic

ner

ve

retin

a

Cili

ary

mus

cle

cornea

how the taste buds gather information

humans detectfour tastes: sweet, sour, salt and bitter

sensory nerves bring messages to the brain