Year 9 Textbook

St. Mary’s College Science Department

Year 9 Science


Year 9 Science

1

M. Logue


Year 9 Science

Pupil Name

Date

2


Year 9 Science

Welcome back to your second year at St. Mary’s College.

Hopefully you enjoyed your summer holidays and are ready to work hard again

this year.

In 2 nd Year you will be learning about a variety of topics including food,

electricity, elements, mixtures, forces and breathing.

The full list of your topics is below…

September to Hallowe’en - Staying Alive

Hallowe’en to Christmas – Forces

January to Mid-term – Matter

Mid-term to Easter – Magnetism and Electricity

April – The Environment

May – Elements, mixtures and separations

June – Numeracy in Science

3


Year 9 Science

Topic 1 – Staying Alive

In this first topic you will be learning about the breathing system and why we

breathe, what is in air, the difference between inhaled and exhaled air and all

about smoking. You will also learn about food and digestion.

Let’s start by thinking about why we need to breathe…

You breathe in air.

The reason we need to breathe is so that

we can ‘burn’ our food to get the energy

out of it.

It’s a bit like how we need to burn coal to

get the heat out of it – we need to burn

our food to get the energy out of it.

As you might know coal needs air in order

to keep burning.

We also need air in order to burn our

food. So we breathe in air.

All the cells in our body need energy to stay alive.

We get this energy out of our food by a process called respiration.

Oxygen is needed for this process to work and we get the Oxygen by breathing.

Respiration happens in each cell of our bodies.

Extension Work

The word equation for ‘respiration’ is…

Glucose (Sugar in food) + Oxygen Carbon Dioxide + Water + Energy

Homework 1

Learn the word equation for respiration off by heart.

4


Year 9 Science

So what if we are doing a lot of work or exercise.

This means we will need more energy.

So we have to burn our food faster – so we need more Oxygen in our bodies.

How will this affect our breathing? You can now carry out a simple experiment

to find out.

Method…

1. Sit still and count how many times you breathe out in 1 minute.

This is your breathing rate at rest.

2. Now do step-ups for 1 minute (light exercise). As soon as you have

finished sit down and measure your breathing rate for another minute.

3. Now do step-ups for 3 minutes (heavy exercise). As soon as you have

finished sit down and measure your breathing rate for another minute.

4. Put your results in a table like this…

Breathing rate at

rest (breaths per

minute)

Breathing rate after

light exercise

(breaths per minute)

Breathing rate after

heavy exercise

(breaths per minute)

Now answer the following questions about your experiment…

Numeracy in Science

1. Draw a bar chart of your breathing rate at rest, breathing rate after

light exercise and breathing rate after heavy exercise.

2. What happened to your breathing rate during the experiment?

3. Why do you think this happened?

Homework 2

Write a conclusion to the experiment you did in class.

Extension Homework

At the top of a mountain there is less Oxygen. How do mountaineers manage?

Why do you think athletes train at high altitude?

5


Year 9 Science

So now that you know why we breathe

in air, we need to look more closely at

‘how’ we breathe in the air.

First the air comes in through the

nose or mouth.

(It doesn’t matter which one the air

enters the body through as they both

join up later anyway).

Next the air goes down a pipe called

the wind-pipe (or trachea).

Then the trachea splits into two pipes

called bronchi.

Each of these bronchi enters a lung.

Inside the lung each of the bronchi

splits into lots of smaller pipes called

bronchioles.

At the very end of every bronchiole is

a bunch of little air-sacs called alveoli.

This is the end of the journey for the

air.

So to summarise the journey of air particles in your body, look at the flow chart

below…

Nose / Mouth

You will need to know the

journey of air through the

parts of the Breathing

System for your End of Unit

Test.

Trachea (wind-

Bronchus (bronchi)

Bronchioles

Alveoli (air-sacs)

6


Year 9 Science

Homework 3

Learn the path or journey of air inside the body off by heart.

Bring in a large plastic bottle to your next lesson.

Extension Homework

1. What happens to the size of your chest when you breathe in?

2. What happens when you breathe out?

3. What happens to your rib-cage when you breathe in?

4. What happens to your rib-cage when you breathe out?

Next you are going to make your own model’ breathing system which will actually

work!

Method:

Cut the bottom off the large plastic

bottle

Stick a piece of plastic bag to the bottom

of the bottle

Use an elastic band to attach a balloon to

the end of a straw

Put the balloon and straw into the top of

the bottle and seal using blue-tac

Homework 4

Look at the diagram of the breathing system and answer the questions.

1. Which part of the body is shown by the bell

jar, the plastic sheet, the balloon?

2. What happens to the lungs when you breathe

out?

3. When you breathe in, does your diaphragm

move up or down?

7


Year 9 Science

Next you need to learn about the air that we breathe.

In particular you need to know what is in air and how this changes between the

air you breathe in and the air you breathe out.

First look at the air around you (the air that you breathe in).

This pie-chart shows the gases

that are in air and how much of

air is made up by each gas.

These numbers are true for the

air all around you (in other words

– the air you breathe in)

Now look at the table below which compares the contents of the air after it has

been through your body – in other words – exhaled air with the contents of

inhaled air.

Name of Gas Inhaled Air Exhaled Air

Oxygen 21 % 16 %

Carbon Dioxide 0.03 % 4 %

Nitrogen 78 % 78 %

Water Vapour Variable (can change) Variable (can change)

Noble Gases 0.97 % 0.97 %

As you can see - air changes when it passes through your body.

If you remember back to ‘respiration’ you can figure out why.

During respiration your body uses up some Oxygen and changes it into Carbon

Dioxide. This is why the amount of Oxygen goes down and the amount of Carbon

Dioxide goes up.

8


Year 9 Science

So air is a mixture of many different gases. The main gases in air are Nitrogen

(78%), Oxygen (21%) and Carbon Dioxide (0.03%) as well as several other gases

which are present in small amounts.

Now you will draw your own pie chart to show the gases in air.

To do this you will need to know about pie charts…

First of all there are 360 o in a full circle.

To find out how many degrees makes 1%

of the circle divide 360 by 100 = 3.6

So 3.6 o makes 1% of the circle.

To show how much of air is Nitrogen,

3.6 by the % of Nitrogen in air (ie 78%).

multiply

So Nitrogen makes up 78% of air which will be 78 x 3.6 o which is 280.8 –

roughly 281 o .

Now try to find out how many degrees of the circle should represent Oxygen

and Carbon Dioxide

Numeracy in Science – Very Difficult

Homework 5

1. Which gas makes up most of the air you breathe?

2. Which gas do you breathe in more of?

3. Which gas do you breathe in less of?

4. Copy and complete this paragraph…

We breathe in air containing Nitrogen, _________ and some Carbon

Dioxide. The air that we breathe ___ contains the same amount of

__________ and less _______ __________. The air we breathe out

also contains more ______ vapour and less _________.

9


Year 9 Science

Now let’s look again at how air changes when it is passed through the body.

The air that you breathe in is about 21% Oxygen but the air you breathe back

out only has 16% Oxygen. So where did the 5% of the Oxygen go?

The answer is – the Oxygen goes into our blood and then into our cells.

This diagram shows Oxygen

(O 2 ) going from the alveolus in

the lung right into the blood

vessel. This Oxygen is then

carried to the cells of the body

where it is used for

respiration.

There is a very simple experiment you can

do to prove that we breathe out Carbon

Dioxide gas.

Use a straw to breathe into a beaker of

Limewater. If the limewater turns cloudy

or milky then you are breathing our Carbon

Dioxide.

Homework 6

Write a method and conclusion for the

experiment you carried out in class.

Include a diagram of the equipment used.

During respiration the Oxygen

is used up and Carbon Dioxide

(CO 2 ) is produced. This Carbon

Dioxide is then carried back to

the alveolus in the lung from

where it is breathed out of the

body.

Method…

1. Pour about 50ml of

limewater into a 100ml

beakers

2. Blow into the limewater

using a straw (Careful –

take care not to suck up

any limewater)

3. Only Carbon Dioxide will

make Limewater turn

cloudy.

10


Year 9 Science

You have now proved that we breathe out Carbon Dioxide.

Next you will see and experiment to prove that inhaled air has more Oxygen in

it than exhaled air.

Method…

1. Set a bee-hive shelf

inside a trough full of

water so that it is just

below the water level.

2. Fill a gas jar full of

The picture above show how to collect a sample of

exhaled air in a gas jar and how to test the exhaled

air for Oxygen.

water and carefully

lower it into the water

in the trough.

3. Turn the gas jar upside down and place on top of the bee-hive

shelf without letting any water out of the jar.

4. Put a length of rubber tubing under the bee-hive shelf and up

into the gas jar.

5. Blow into the other end of the rubber tubing – the air you

breathe out will replace the water in the gas jar.

6. Now test the exhaled air and a sample of ordinary air for

Oxygen content by timing how long a burning candle stays lit in

each sample of air.


Sample of

air

Inhaled

Exhaled

Time for candle to be extinguished (seconds)

1 2 3 Average

Homework 7

Write an aim, equipment, method, results table and conclusion for the

experiment to collect exhaled air and compare the Oxygen level of inhaled

and exhaled air.

Extension Homework

Learn the percentages for each of the main constituents of inhaled and

exhaled air

11


Year 9 Science

Next you will be looking again at how Oxygen in the air you breathe in gest into

your blood. To do this you will be looking at a real lung being dissected.

Lung Dissection

The teacher will dissect a cow’s

lung and you should be able to see

the trachea, bronchi and even the

bronchioles and alveoli. You should

also see the blood vessels around

the alveoli.

Now you need to learn how the Oxygen in

the inhaled air gets into your cells for

respiration to happen.

You already know that you breathe in air

which goes down your trachea, bronchi and

into the bronchioles inside your lungs. Then

the air goes into the air-sacs (alveoli).

The air you

breathed in is now

inside the air-sacs

(alveoli).

There are tiny

blood vessels called

‘capillaries’

wrapped around

the alveoli and the

Oxygen passes

through the walls

of the alveoli and

the capillaries

right into the

blood-stream.

The blood capillaries

are wrapped around

the air-sacs.

Oxygen passes through

from the air-sacs into

the capillaries.

12


Year 9 Science

Homework 8

1. How does Oxygen get from your lungs to all the cells of your body?

2. How does Carbon Dioxide get from your cells to your lungs?

3. Which gas passes from the air-sacs into the blood vessels?

4. Which gas passes in the opposite direction?

5. Why do air-sacs and capillaries need to have very thin walls?

Extension Homework

Earlier you carried out the experiment where you breathed through a straw

into a beaker of Limewater. The Limewater turned cloudy because you breathe

out Carbon Dioxide.

Now can you explain why a mirror turns misty when you breathe onto it?

Numeracy in Science

Una and Dearbhla measured their breathing rates (in breaths per minute)

before they ran a race. Then they measured their breathing rates again after

the race, every minute, until their rates returned to normal. They recorded

their results in a table.

Before

exercise

Minutes after exercise

1 2 3 4 5 6 7 8

Dearbhla 16 45 38 31 24 20 18 17 16

Una 13 35 32 28 25 22 18 13 13

a. Plot 2 line graphs on the same graph page. Use the x-axis for time and

the y-axis for breathing rate.

b. Who took longer to recover from the exercise?

c. Who do you think was the fitter of the two girls? Why?

13


Year 9 Science

Next you are going to learn about smoking – what is in cigarettes and what they

can do to your health.

First look at what is in cigarettes…

Tar

Nicotine

Carbon Monoxide

These are the three main constituents of tobacco although there are hundreds

of others.

Now look at what these chemicals can do to your body.

Name of constituent

of tobacco

Tar

Nicotine

Carbon Monoxide

What it does to your body

A brown sticky substance that collects in your lungs if

you breathe in tobacco smoke. It is known to cause

cancer.

An addictive drug which goes into the blood in your lungs

(the same way Oxygen does). It causes your blood

pressure to rise and your heart to beat faster.

A poisonous gas that prevents your blood from carrying

as much Oxygen as it should and so you get out of

breath easily.

You can investigate the effects of smoking by using the Smoking apparatus.

The cigarette is lit and is

inhaled’ by a water pump

attached to the apparatus.

The cotton wool acts like our

lungs – you can see how it

gets stained and smelly and

even heavier with the tar.

The universal indicator shows

how the Carbon Monoxide is

acidic (think back to when

you studied acids and alkalis

in Year 8)

14


Year 9 Science

Homework 9

Copy and Complete…

Cigarette smoke contains poisonous ______. One is a drug called ________.

This gets into your blood in the ______. It causes your blood __________

to rise and your heart to beat ________. Tar contains chemicals which

cause ________. A poisonous gas called _________ __________ stops

your blood from carrying as much ________ as it should.

Extension Homework

1. Using the information in the diagram, explain why smokers should give

up smoking.

2. Write down what you think about the following statements…

Smoking should be banned in public places like parks

Once you start smoking, it’s hard to stop

Smoking costs a lot of money

You can get lung cancer by breathing in other people’s cigarette

smoke

3. Make a leaflet about the dangers of smoking.

15


Year 9 Science

So far in this topic you have learned about how we breathe and how we use the

Oxygen to do respiration (get energy from food).

Next you will be learning about how we get food to our cells through our

digestive system as well as about the different nutrients in food and how to

test foods for the presence of these nutrients.

First you need to know what is meant by a ‘balanced diet’

A balanced diet is one that gives your body the nutrients it needs to work

properly.

In order to eat a balanced diet you need certain amounts of the different

‘nutrients’.

The main nutrients in food are as follows…

Name of

Nutrient

Carbohydrate –

Starch

Carbohydrate –

Sugar

Protein

Fat

What it does for the body

Provides energy (a slow

release of energy over a

longer period of time)

Provides energy (a quicker

burst of energy that doesn’t

last as long)

Helps the cells grow and

repair

Provides warmth and a store

of energy

Examples of foods which are

rich in this nutrient

Pasta, Rice, Bread

Chocolate, sugary drinks like

coca-cola etc

Red meat, Chicken, beans and

peas, nuts

Butter, Cheese, Fred foods

Minerals – Iron Help the body replace red Leafy vegetables,

blood cells

Minerals – Helps strengthen bones Milk, butter, yoghurt, cheese

Calcium

Vitamin C Strengthens the immune Oranges, peppers, kiwi

system, prevents scurvy

Vitamin D Helps strengthen bones Fish, egg yolk, liver, cheese

Fibre Prevents constipation Cereal grain, bran, brown rice,

beans, nuts

You need to know the information in this table for your End of Unit Test.

16


Year 9 Science

Homework 10

Learn the main nutrients in food, what each does for the body and some

examples of foods which are rich in each nutrient.

Extension Homework

Carry out research to find out what each of these vitamins and minerals are

needed for…

Vitamin B

Iodine

Vitamin A

ICT in Science - Task

If you have time you can now produce a power-point presentation about one of

the main nutrients in our food.

Your presentation should include a title slide, a slide about what the nutrient

does for our bodies, a slide about what types of food are rich in this nutrient

and finally a slide about what could happen if we don’t get enough of this

nutrient.

Good Luck!

Next you are going to learn about how we can actually test foods to see if they

contain certain nutrients.

In particular you will carry out experiments to test a range of foods for the

presence of Carbohydrate Starch, Carbohydrate Sugar, Protein and Fat.

17


Year 9 Science

Food Test Experiment 1

Testing foods for the presence of starch (Carbohydrate)

You will need …

A Dropper Spotting tray Iodine and some foods

Method…

1. Place a small piece of the food in a spotting tray.

2. Add a few drops of Iodine solution.

3. If the Iodine stays brown/orange then there is no starch. If the

Iodine turns a blue/black colour then there is starch in the food.

You should put your results in a table like this one…

Name of Food

Colour of Iodine on

Food

Is starch present in

Food (Yes/No)

18


Year 9 Science

Did you know…

Starch is a form of Carbohydrate.

Sugar is actually another form of Carbohydrate.

Starch molecules are long and it takes the body a while to break them down

small enough to fit into the blood stream (so they can be carried to our cells for

respiration).

Sugar molecules are shorter so they can enter the blood much more quickly.

Carbohydrates get their name because they are made of Carbon and Hydrogen

(as well as some Oxygen).

Homework 11

When some foods are made, chemicals are added. These are called Food

Additives. Some of the Food additives make the food last longer, some give the

food more flavour or a better appearance. A lot of these additives have names

that begin with E and then a number – for example E330 or E340.

Carry out some research into the foods in your home and list all the E-numbers

in the foods. Use the internet to find out why each E-number has been added to

the food.

Extension Homework

Starch gives you energy (and so does Sugar)

Carry out research to find out how much energy different people need each day

a. A 1 year old child

b. A 13 year old girl

c. An adult man who works in an office

d. A pregnant woman

e. An adult man who works as a builder

19


Year 9 Science


Testing foods for the presence of Sugar

You will need…

Benedict’s Boiling tube Bunsen Tongs Heat-proof mat

Solution

Burner

And of course different foods!

Method…

Food sample

Benedict’s

Solution

Water

1. Place sample of food in boiling tube.

2. Add several drops of Benedict’s Solution.

3. Place boiling tube in beaker of water.

4. Heat beaker of water over a Bunsen Burner.

5. If Benedict’s Solution stays blue then there is no sugar in the food. If

Benedict’s Solution turns brick red/orange then the food contains

sugar.

6. Put your results in a table like this one…

Name of Food Colour of Benedict’s Is sugar present in

Solution after heating Food? (Yes/No)

20


Year 9 Science

Homework 12

Write a conclusion to the experiment to investigate which foods contain glucose.

Extension Homework

Research what is meant by junk food.

Explain why you think a lot of children eat so much junk food.

Why is it important to eat fruit and vegetables?


Testing foods for the presence of Protein

Add 10 drops of Biuret

solution to a test tube

containing the food and some

water. Shake for a minute.

If it remains blue, there is no

protein present. If it turns

lilac, protein is in the food.

Put your results in a table like

the one below.

Name of food

Colour of Biuret solution

in food

Is protein present?

Yes/No

The last food test is to test foods for the presence of Fat.

To do this you will only need some filter paper (or brown paper) and the foods

you want to test. The method is on the next page.

21


Year 9 Science


Testing foods for the presence of Fat

Rub some of the food onto a

piece of filter paper.

Hold the filter paper up to the

light. If it appears translucent

(some light is passing through

it), then the food contains fat.

Put your results in a table like this one…

Name of food

Does it contain fat? Yes/No

Now you should try to collect the results from all 4 food tests in one results

table. Your title for the table should be ‘Summary of Results from Food Tests’

The blank table below will give you an idea of how to do this…

Name of

food

Does it contain…

Starch? Sugar? Protein? Fat?

Put a tick in the box if that nutrient is present in the food.

Homework 13

Copy and complete the table below…

Nutrient Use to my body Foods containing a lot of it Chemical Test

Starch

Sugar

Protein

Fat

22


Year 9 Science

Now you need to learn about our teeth –what the different types are, how many

of each type we have and what they do.

Firstly you need to know that an

average adult has 32 teeth.

There are 4 different shapes of

tooth. These are in the diagram on

the left.

The diagram below shows you the shapes of the 4 types of tooth more clearly.

The table below gives information on the different types of teeth.

The diagram above shows you where

the different types of teeth are in

the upper and lower jaws.

23


Year 9 Science

You also need to know the structure of a tooth.

The diagram below shows this in some detail.

The outer layer which is a white (or

slightly off-white) colour is called

enamel. It is very hard and protects

the inside of the tooth.

Inside the enamel is dentine.

Then there is a pulp cavity which has

nerves and blood vessels inside it.

You need to know the structure of a tooth off by heart.

Homework 14

Copy and complete…

The hard coating on the outside of a tooth is called __________. It

surrounds a softer layer called _________. In the middle of the tooth is the

pulp _________ which contains ______ vessels and ________.

Extension Homework

a. When you have a tooth taken out why does it bleed and feel sore?

b. What foods could you eat if you had no teeth?

c. Suppose you had to give a 2 minute talk to primary school pupils about

caring for their teeth. Write down what you would say.

Did you know…

that sugar combines with bacteria in your mouth to make acid which can

corrode your teeth

24


Year 9 Science

Next you are going to learn about the ‘Digestive System’ and how our bodies

deal with our food.

Mouth – food chewed by teeth and

mixed with saliva. Then you swallow

(gulp!) Food is here for about 20

seconds.

Oesophagus (gullet) – a straight

muscular tube leading to your

stomach.

Stomach – The acid bath!

Digestive juices and acid are added to

food here. Your stomach churns the

food and makes it like vomit!

Small Intestine – More juices are

added from your liver and pancreas.

These complete digestion. Then the

nutrients in the food pass into your

blood.

Large Intestine – Food which cannot

be digested reaches the large

intestine. Water is absorbed and the

solid waste passes out of the body

through the anus

You need to learn the parts of the digestive system and what each part does.

Homework 15

Learn the parts of the digestive system and the job of

each part.

Extension Homework

Carry out research to find out…

How long does it take food to pass down the whole length

of the digestive system?

Scan the QR

code to watch a

video explaining

the digestive

system

25


Year 9 Science

Next you are going to learn a little bit more about the two

main types of Carbohydrate these are Starch and Sugar (Glucose)

Both these substances are made from the same elements

but the main difference between is the length of their molecules.

Look at the diagrams below to find out more…

William Beaumont

was a surgeon who

first taught us

about the working

of the digestive

system.

Starch molecules are very

long – too big to fit into your

blood stream.

Chemicals in your saliva and

digestive system called

‘enzymes’ act like scissors

and ‘cut’ the starch

molecules making them

shorter.

The smaller molecules are

‘sugar’ molecules which are

small enough to go into your

blood stream.

So starch has to be broken down into sugar before the molecules can pass from

your digestive system into your bold to be carried to your cells for respiration.

Do you remember…

Respiration is how you get energy from your food.

It happens in your cells when Sugar from you food reacts with Oxygen from the

air you breathe in to make energy.

Glucose + Oxygen Carbon Dioxide + Water + Energy

26


Year 9 Science

In a similar way some other nutrients you have learned about need to be broken

down by ‘enzymes’ too so that they can be passed into the blood stream.

Here are two examples…

Proteins are large molecules made up of smaller ‘amino acid’ molecules.

Be careful – the enzymes that break

down proteins are different from the

ones which break down starch.

Protein molecules are long

and large and can’t be

passed into the bold

stream.

However if ‘enzymes’

break down the protein

molecules into smaller

pieces – amino acids –

these can be passed into

the blood stream

Amino acid molecules can

pass into the blood stream

and be carried around the

body where they are

needed.

It is exactly the same for fat molecules…

Can you describe what happens this time?

Remember – the chemicals that break down your foods into smaller molecules are

very specific. This means that the enzyme that breaks down starch will not work

to break down protein and so on.

27


Homework 16

Year 9 Science

1. Match the parts of the body in the first column with the description in

the second column…

Stomach

Small intestine

Large intestine

Mouth

Gullet

most water is absorbed here

saliva is made here

most food is absorbed here

carries food down to the stomach

is very acidic

2. The graph below shows the effect of temperature on how quickly an

enzyme can digest food.

Numeracy in Science

Rate of Reaction

X

Y

Z

0 10 20 30 40

Temperature ( o C)

a. At what temperature is the enzyme most active?

b. Why do you think the enzyme works best at this temperature?

c. Explain what is happening to the action of the enzyme between X and Y

and also between Y and Z.

Extension Homework

1. Find out how each of the following parts of the body helps digestion to

take place…

a. Liver

b. Pancreas

c. appendix

28


Year 9 Science

The last thing you need to know in this topic is how to carry out an experiment

to show how smaller food molecules like sugar can pass through the wall of the

digestive system but larger molecules like starch cannot.

The model digestive system wall

Method…

1. Wash the Visking tubing in warm water to soften it.

2. Tie one end in a tight knot.

3. Use a dropper to fill the tubing with 5 ml of starch solution and

another dropper to put in 5 ml of sugar solution.

4. Wash the outside of the tubing.

5. Tie the other end of the tubing tightly and then tie it onto a glass rod.

6. Lower the tubing into a beaker of water and wait for 15 minutes.

7. After 15 minutes pour the water from the beaker into two separate

boiling tubes and label them sample A and sample B.

8. Test sample A with iodine to see if it contains starch (Hint: Look back

at the Food Test experiment to see what colour change to look out

for).

9. Test sample B with Benedict’s solution to see if it contains sugar

(Hint: Look back at the Food Test experiment to see what colour

change to look out for).

10. Record your results.

29


Year 9 Science

Homework 17

1. Look at the diagram below and answer the questions that follow…

a. If you think of the wall of the gut

as having small holes like the

diagram to the left, explain how

small molecules can pass through

but larger molecules cannot.

Extension Homework

1. Explain how the red molecules can pass through the Visking tubing and

the blue molecules cannot.

Before

After

Visking tubing

2. Look at the diagram and explain why the water in beaker B will contain

sugar but the water in Beaker A will not contain starch.

Beaker A

Beaker B

30


Year 9 Science

You are now finished this topic and you need to prepare for your End of Unit

test.

Use the Mind Map below to help you.

The parts of the

breathing system

and their jobs

Why and how we

breathe

The word

equation for

‘respiration’

The gases in air and

how much of each

gas is in inhaled and

exhaled air

Staying Alive

The contents of

tobacco and what

each does to our

bodies

How to carry out and

interpret food tests

for starch, sugar,

protein and fat

The different

types of teeth and

their shapes and

jobs

How molecules pass

into the blood from

our digestive

system

The parts of the

digestive system

and their jobs

The main

nutrients in food

Careers in Science

Nutritionists use their knowledge of Food Science to give

people advice on their diets either to improve their general

health or to help them deal with allergies or food

intolerances. They can work for food companies,

sports teams or for the Health Service.

31


Year 9 Science

Topic 2 – Forces

The next topic is all about forces.

A Force is a push, a pull, a turn or twist or a lift.

Forces make things move, speed up or slow down,

stop things moving, change the direction or shape of things.

Look at the diagrams below and decide which ‘force word’

best describes each one. The answers are at the bottom of the page.

Scan the QR code to

watch a video on

what forces are

A

B

C

D

E

F

Can you think of 5 things you have done today that used a ‘force’?

When you use a force like a push or a pull, you will be pushing or pulling in a

certain direction. The diagrams below show the direction of each force by using

an arrow.

Answers to questions A – F above…

A=Push; B=Squeeze; C= Hit; D= Pull; E=Twist; F=Lift

32


Year 9 Science

Imagine you have to lift up two boxes – one is large and heavy and the other

one is smaller and lighter.

How would you describe to your friend how hard each one is to lift – how big

a force you need? Would you just describe the difference in words – this one

needs a bigger force to lift than the other one.

It would be better if we could use numbers so we could compare lots of

forces and describe them all accurately. To do this we need a way to

‘measure’ forces. (Remember you learned about ‘measurement’ earlier in the

topic ‘Introducing Science’) Numeracy in Science

To measure forces we use a force-meter. There are several different types

of force meter – some of them you might have in your house.

One type of force-meter is called a ‘spring balance’

or ‘Newton-meter’.

It is named after Isaac Newton, a very famous

scientist.

It is made of a spring which gets longer when a

weight is hung from the end of it.

A scale then tells us how heavy the weight is by

changing the length of the spring into a unit of

33


Year 9 Science

A B C D

Isaac Newton was

a very famous

scientist who

taught us a lot

about forces and

also about light.

Look at the ‘Newton-meters above and decide what

force reading each one is showing.

You are going to carry out an experiment to practice

using a ‘Newton-meter’ and to find out what force is

needed to move a variety of objects.

The method is as follows…

1. Hook the object around the hook at the

bottom of the Newton-meter.

2. Lift or drag the object smoothly (do not jerk

it quickly)

3. Allow the spring time to stop moving up and

down and then take a reading against the scale.

4. Copy out the results table below and put your

results in it.

Name of Object

Estimated Force

needed to move it

(Newtons, N)

Actual Force needed

to move it

(Newtons, N)

There is a very famous story

about Isaac Newton. He was

sitting under an apple tree

when an apple fell and hit him

on the head. It made him think

about why things fall

downwards and he ‘discovered’

gravity.

Homework 1

Draw a bar chart to show

the forces needed to

move the objects you

tested in class.

Numeracy in

Science

34


Year 9 Science

Next you need to learn about one force in particular.

It is called ‘friction’ and it is caused by the rubbing of surfaces against each other as

they move past each other – for example a book being pushed along the bench and

rubbing against the bench as it moves.

The diagram below shows you that

even when a surface looks smooth, it

is often actually very rough.

This is how friction happens between

surfaces.

The rough surfaces catch against each

other as the surfaces move over each

other and this slows down the movement.

Friction always works against movement

but it can never make something move.

In the diagram to the left the

pushing force makes the box move to

the right hand side. Friction works in

the opposite direction trying to slow

or even stop the movement.

Sometimes friction can stop the

movement; often friction just slows

things down.

Friction can even get bigger if you push harder to move an object.

But friction can never become bigger than the pushing force.

35


Year 9 Science

There is less friction when the

two surfaces in contact are

smoother like the ones on the

far left. There is more friction

when the two surfaces are

rougher.

This is why it is easier to drag the box over a tiled surface (smoother)

than it is to drag it over a rougher, more uneven surface (the carpet).

Sometimes these are more than two

surfaces rubbing or moving over each

other in a certain situation. In the

diagram on the right there is friction

between the box and the floor and

also between the woman’s shoes and

the floor. The friction between the

box and the floor makes it harder for

the woman to move the box. However

the friction between her shoes and

the floor actually helps because it

‘stops’ her feet from slipping!

So sometimes friction can be useful and sometimes it can be a nuisance!

Homework 2

In each case decide if friction is useful or a nuisance.

a. Steering a car around a corner c. Skiing

b. Pushing a box across the floor d. Putting on your brakes on a bike

36


Year 9 Science

So friction can be described like this…

Friction is the force between the surfaces of

two objects rubbing together as one or both of

them move. It is a contact force. Friction can

cause moving things to slow down or even stop

altogether and can also have a heating effect on

the two surfaces which are in contact.

Try this…

If you take some time and

interweave the pages of two books –

one page overlapping with another

you can see how strong friction can

actually be when you try to pull the

two books apart.

Friction can be useful (walking, brakes, lighting a

match) or a nuisance (pushing heavy objects).

Now you are going to carry out an experiment on friction to see for yourself the

effect of rough surfaces compared with smoother surfaces.

Method…

1. Place one of the friction surfaces to be tested on the bench and hold it in

place with a G-clamp.

2. Using string attach a weight holder to the block to be moved and put the

string over the pulley.

3. Now add weights to the weight holder until the block begins to move. Count

the number of weights needed to move the block over this surface.

4. Repeat with other surfaces.

5. Put all your results in a table like this.

Type of

surface

Number of weights needed to move

block

37


Year 9 Science

There is another way to get

results from the experiment –

using a spring balance to

measure how much force is

needed to overcome the

friction of each surface.

Another experiment you can carry out to find out more about friction is

explained below…

To find out which type of shoe has the best grip (friction with ground) you

can put a certain weight in each type of shoe and use a spring balance to find

out how much force is needed to overcome the friction of its grip and make it

move over the floor.

Put your results in a table like this

one…

Type of shoe

Force needed to

move shoe and

weight inside it (N)

Homework 3

Numeracy in Science

Plot a bar graph for either experiment on friction – number of weights for

each surface or force for each type of shoe

38


Year 9 Science

Another nice experiment to try will show you

how friction depends on the amount of

surface contact.

Put a wooden rod into a plastic bottle and

then pour rice into the bottle until it is filled

with rice. You will now be able to hold the

bottle using the wooden rod – friction stops

the rod from sliding out of the bottle.

Leonardo is very famous as an

artist – but did you know he

was also an excellent

scientist. He taught us a lot

about friction.

Sometimes we want to reduce or lessen friction – particularly when we are

trying to make something move.

Here are a couple of examples of how we can reduce friction…

Have a cushion of air between

the two surfaces which are

going to be rubbing together –

like in the balloon hovercraft

(or a real hovercraft) or the

linear air track which your

teacher might show you.

Another way to reduce friction is to put marbles, ball

bearings (which are steel marbles) or rods between

the two surfaces so they can slide over them as the

rods or marbles roll around.

A third way of reducing friction is to put a liquid (such as oil or water

between the two surfaces so they the rough edges are not actually

touching anymore and so they can’t catch against each other.

This is why we ‘oil’ bicycle chains or hinges on doors to keep them

moving by reducing friction.

39


Year 9 Science

Now try these questions…

1. Copy and complete the paragraph by filling in the blank spaces…

Friction is a ______ which exists between 2 ________ when they are

moving over each other. The ______ the surfaces are the more friction

there will be. Sometimes friction is useful but sometimes it is a

_____ - for example when you are walking friction is ________ but when

you want to put on the brakes on your bike, friction is a _______.

2. Name three ways of reducing friction.

3. Look at the results from a friction experiment and answer the questions

which follow.

Type of shoe Force needed to move shoe over floor (N)

1 st attempt 2 nd attempt Average

Nike Trainer 11 13

House slipper 6 4

Converse 7 9

Adidas Trainer 12 13

School shoe 9 10

a. Calculate the average force needed to move each type of shoe.

b. Which type of shoe has the best grip?

c. Which shoe would be the best for doing P.E?

d. Which show has the worst grip?

Numeracy in

Science

Homework 4

The braking distance of a car is the distance it travels when the brakes are on until it actually

stops. This distance can be affected by the speed of the car, how good the brakes and tyres are

and what the road conditions are. The brakes use ‘friction’ to stop – the tyre rubbing against the

brakes and the road. Look at the graph and answer the questions which follow.

a. Which type of car has the

best brakes?

b. Which car has the worst

brakes?

c. How do you think the

braking distances of the

cars would change if the

road was wet with rain?

40


Year 9 Science

Another type of friction is when a moving thing rubs against the air!

The air hits the moving object and causes it to slow down.

This is called ‘Air Friction’ or ‘Air Resistance’

To reduce this type of friction we use ‘streamlining’. This just means making the

object a certain shape to try to avoid the air hitting the object so much. The

diagrams below show how streamlining works.

This high-speed train is perfectly streamlined to allow the air to move past it

rather than hit against it and slow it down. This is why it can go so fast. The

diagram on the right shows how a shape like the train can allow air to flow

past. Imagine the front of the train was totally flat!!

Can you think of any other streamlined shapes (Hint: think of some animals)?

Homework 5

Using the idea of ‘Air resistance’ can you explain the following…

a. A scrunched up sheet of paper falls faster than one which is not scrunched up.

b. A parachute makes a person fall more slowly.

c. A dolphin can swim very quickly through the water

Extension Homework

a. Explain how rockets and bullets are able to travel so fast

b. Explain why a hawk folds its wings when it is diving downwards but then opens

them out near the ground.

41


Year 9 Science

Next you are going to learn about why things float or sink.

One of the cans in the picture below floats and the other sinks. Why? They

both have the same volume of liquid in cans of the same size.

Your teacher will show you an experiment

to test if each can sinks or floats. The

answer is shown on the next page.

Why do you think one floats and the other

sinks if they are the same size? Is it

simply to do with weight? If you think so

then the next experiment might make you

think again!

Your teacher will now demonstrate an

experiment to show how you can make an

orange sink even though it normally floats.

Try putting an orange in water and it

should float. Now peel it (which should

make it lighter!!) and try again – it now

sinks.

So the answer isn’t just to do with weight!

So we still need to answer the question – why do things sink or float? Another

thing to think about is that a 2 pence coin sinks but a huge ship floats. Why?

The answer must be something to do with water. You need to investigate this by

carrying out an experiment.

The method is as follows…

You will need…

Basin String Materials Block Newton-meter

42


Year 9 Science

Method (continued)

1. Tie a piece of string around a block of one of the materials and attach

the other end of the string to a Newton-meter

2. Read the weight of the block on the Newton-meter scale.

3. Now fill a basin of water and hold the block in the water so it is just

below the surface. Read the weight from the Newton-meter scale again.

4. Repeat this for all the different materials and put all the results in a

table like the one below.

5. Finally test each material block to see if it sinks or floats.

Name of

material

Sink or float?

Weight in air

(N)

Weight in water

(N)

Can you see a rule that is true for all ‘floaters’?

It seems that there is a force from the water trying to hold the blocks up –it

can hold some materials blocks up and they float but some blocks are not held

up enough and they sink.

This force from water is called ‘Upthrust’ – sometimes it is also called the

‘buoyant force’

The Weight of the block is caused

by the gravity of the earth pulling

the object down towards the

ground. The upthrust of the water

pushes upwards against the weight.

By the way – the coke sank

and the diet-coke floated.

It’s because the coke has

sugar so it is heavier even

though it is the same size –

we say it is more dense.

43


Year 9 Science

Extension Work

Do you remember the scientist called ‘Arcimedes’? He

discovered that when an object is put in water the

‘upthrust’ force is equal to the weight of the water that has

been displaced.

So if an object weighs more than the water it displaces it

will sink and if it weighs less than the displaced water, it

will float!

You can investigate this more closely with your teacher.

Don’t worry – you don’t have to know this bit for your End of Unit Test on

Forces!

Homework 6

1. Copy and complete this paragraph…

Weight is a _______ caused by the force of ______ pulling things down

towards the ground. When an object is placed in water there is a force

called _________ pushing up on the object. When an object sinks the

upthrust is __________ than the weight and when it floats the upthrust is

__________ to the weight.

Extension Homework

1. Look at the diagram. The weight of the

object in air is 40N. Its weight is water

is 25N.

What is the upthrust force of the

water?

Does this object float or sink?

Extension Activity…

You could investigate the surface tension in water too.

Try this at home. Place a paper clip in a glass of water – it floats.

Now put one drop of Fairy liquid into the glass of water. What happens?

44


Year 9 Science

The last thing you need to know in this topic is how to work out the resultant

force when there is more than one force in a situation.

Imagine that Man Utd beat Liverpool in a match by a score of 3-1.

Man Utd win the match but by how many do they win?

The answer is that Man Utd win by 2 goals : 3 minus 1 = 2.

This is the result of the match.

What if two forces are acting against each other? Look at the diagram below.

In the top diagram the forces are the

same size but in the opposite direction.

We say that the forces are balanced so

the resultant force is 300 – 300 = 0.

In the second diagram however the

team on the left have a force of 400N

so the resultant force is 400 – 300 =

100N to the left.

Let’s say that the woman is

pushing the sofa with a force of

200 Newtons and the friction

force is 150 Newtons.

So the resultant force is 200 –

150 = 50 Newtons and the

woman can move the sofa.

Look at these diagrams and how the resultant forces are calculated.

45


Year 9 Science

Now look at these diagrams and calculate the resultant forces.

If two forces are in the same direction then you add

them together to find the resultant force.

If two forces are in opposite directions, then you

subtract one from the other to find the resultant force.

The diagram below shows this.

Imagine a car travelling

along a road. If the force

of the engine is bigger

than the friction then the

car has a resultant force

forwards and this

resultant force will make

the car accelerate (speed

up).

If the two forces are

balanced, then the car

will travel along at a

steady speed.

We normally show the size and direction of forces by using arrows. The

direction of the force is simply shown by the direction of the arrow. The size of

the force can be shown by the length of the arrow (or sometimes the

thickness).

Look at these examples…

46


Year 9 Science

Homework 7

1. Copy and complete…

An object can have more than one ______ acting on it. If there is no

overall resultant force then the object’s movement does _____

change.

2. Use a scale of 1cm for each Newton to show a diagram of a book

being pushed along a bench with a force of 6N and a friction force of

2N.

3. Look at the diagram of a woman

pushing a sofa. Copy the picture

into your exercise book and draw

an arrow to show a pushing force

of 100N and a friction force of

75N. Will the sofa move?

Next you are going to learn about the difference between ‘Mass’ and ‘Weight’

Basically ‘Mass’ is the amount of matter (stuff) you are made up of. You cannot

change this quickly – unless you lose on put on mass by exercising or eating a lot!

Mass is measured in ‘grams’ or Kilograms’.

Weight is different – it is a measure of how much the earth’s gravity is pulling

you downwards (onto the scales). Weight is a force (of gravity) so it is measured

in Newtons (N).

Weight and Mass are connected by this equation…

Weight = Mass x Gravity

47


Year 9 Science

So for example…

If a girl has a mass of 70 Kilograms and the force of gravity on Earth is 10,

then her weight is…

Weight = Mass x Gravity

Weight = 70 x 10 = 700N

Now try these questions about mass and weight…

(Assume that gravity on earth is 10 N/Kg.

1. If a boy has a mass of 45 Kg, what is his weight?

2. If a car has a mass of 1000 Kg, what is the weight of this car?

3. An astronaut has a mass of 80 Kg. If she goes to the moon where

Gravity is only 1.6 N/Kg, what is her weight on the moon?

What is her normal weight on earth?

Homework 8

1. Ciara has a mass of 53 Kg. What is her weight? What would Ciara’s

weight be on planet Zog where the force of gravity is 3 N/Kg.

2. Can you explain why you would be able to jump higher on the moon

than you can on earth?

3. The amount of force you need to lift up an object is equal to the

weight of the object. What force would be needed to lift an object

with a mass of 90 Kg?

Show your working out.

48


Year 9 Science

The last thing to do in this topic is to make a rubber band racer to show how

you can store your force as energy within a twisted rubber band and when you

let it go the stored energy produces a force to make it move.

Your teacher will give you instructions on how to make your rubber band racer.

You are now finished this topic and you need to prepare for the End of Unit

test.

Try these questions to help you revise for your End of Unit test…

1. Streamlining reduces friction. Give 3 examples of streamlining in animals

and explain how it helps the animals.

2. How is friction reduced in a hovercraft?

3. How is friction reduced in a racing car?

4. How is friction reduced in a yacht?

5. What is the unit of Force?

6. What is the name of the piece of equipment which measures force?

7. Give 3 examples of situations when friction is useful or helpful.

8. Give 3 examples of situations when friction is a nuisance.

9. What is the unit of Weight? What is the unit of mass?

10. What is the value of gravity on earth?

Upthrust in

You should also revise every page

water

in the unit ‘Forces’ in this booklet.

Testing the grip

of different

shoes

Balanced and

Unbalanced forces

What are

Topic 2

forces – force

‘Forces’

words

What is

friction?

Showing the

direction of forces

with arrows

How to

measure

forces: Force-4meters


Careers in Science

Year 9 Science

An engineer designs materials, structures and buildings and they have to

consider health and safety, laws and regulations and cost.

To become an engineer you normally need to get A-levels

in science or engineering and then go to university to do

a degree. After that you may need to do 4 to 6 years

working for an engineering business before you are

fully qualified.

Literacy in Science

Force – needed to make things move, can also speed up or slow down things

Newton – the unit of force

Friction – a force which always acts against movement

Streamlining –giving moving objects a smooth shape in order to reduce friction

Spring Balance – a piece of equipment used to measure forces

Mass – the amount of matter or stuff in an object, measured in Kilograms

Weight – the force of gravity on an object, measured in Newtons

50


Year 9 Science

Topic 3 – Matter

Matter is the scientific word for what all materials are

made from – everything from air to water, from wood to

steel, from plastic to your skin and bones is made from

matter!

All matter can be put into one of three groups…

Solids, Liquids and Gases – these are known as the 3 states of matter.

Now look at the materials and objects in the images below and

decide if each one is solid, liquid or gas

(or even a combination of two states!!)

Put your answers in a table with the headings Solid, Liquid and Gas.

Scan the QR Code

to watch a video

about matter.

Balloon of air

Steel

Fizzy water

Carbon Dioxide

Mercury

Milk

Oxygen

Polystyrene

Wood

Water

51


Year 9 Science

Look again at the materials and objects in the previous page and decide if any of

them are a combination of solid, liquid and gas.

You might be able to look at another material which is sometimes like a liquid

and sometimes more like a solid if your teacher allows you to make slime.

You’ll need corn-flour, water and some food colouring to give it a nice yucky

colour!

+ + =

Have fun making slime!

Next you need to know about the properties of solids.

What is your property? It is the things that belong to you. The properties of a

material are the ways to describe it – is it hard or soft, tough or breakable,

transparent or opaque, strong or weak etc.

The table below describes the properties of solids, liquids and gases…

Solids… Liquids… Gases…

Keep a fixed shape Take the shape of the

container

Take the shape of the

container and fill it up

Keep a fixed volume Keep a fixed volume Take the volume of their

container

Cannot be squashed Cannot be squashed Can be squashed

Cannot flow Can flow* Can flow*

*Because

they can

flow, liquids

and gases

are

sometimes

called

‘fluids’

Homework 1

Copy out these sentences in your exercise book and fill in the blanks

using the words solids, liquids or gases…

__________ are runny. __________ are hard. _______ can be

poured. __________ take the shape of the container. _________ have

a fixed shape. _________ and ___________ cannot be easily

52


Year 9 Science

Next you need to learn about why solids, liquids and gases have the

properties they do.

All matter is made up of tiny little particles called atoms. You can’t see

them as they are extremely small. In fact you can’t even see them with a

microscope. About 40 million billion atoms would fit on the full stop at the

end of this sentence.

Solids, liquids and gases are all made up of these tiny atoms – the

difference is how the atoms are arranged beside each other.

You can see from the

diagrams on the left

that solids, liquids and

gases are all made up

of particles. Can you

see how they are

arranged?

In solids the particles are very close together and they

are in rows and columns. They are so close they cannot

be squashed any closer (that’s why solids can’t be

squashed). They are stuck together (that’s why solids

keep their shape). The particles do vibrate slightly.

In liquids the particles are still close together (that’s

why they can’t be squashed). The particles are not

arranged in rows – they can move around a little as they

are not stuck together like they are in solids.

In gases the particles are not close together at all –

they are very far apart – and they move around a lot in

all directions with a lot of energy and speed. This is why

gases spread out and fill the containers they are in.

53


Year 9 Science

The particle arrangements for solids, liquids and gases are summarised in the

table below…

Particles in solids Particles in liquids Particles in gases

Are very close together Are close together Are far apart

Are in rows and columns Are not arranged in rows Are not arranged at all

Do not move around Move around a little Move around a lot

Are stuck together

strongly (strong bonds)

Cannot be squashed

closer together

Have weak bonds

between them

Cannot be squashed

closer together

Have no bonds between

them at all

Can be squashed closer

together

You can try a few short experiments to see some of these properties..

Scan the QR

code to watch

a video about

solids, liquids

and gases

Try squeezing an empty plastic bottle. You will probably find that you can do

this quite well. Gases can be compressed.

Now fill the bottle to the brim with water, put on the lid tightly again and try

squeezing it again. This time you will find that you can’t really squeeze it.

Liquids cannot be compressed.

Next try to squeeze a rock. Obviously this can’t be done because solids can’t be

compressed.

Homework 2

Copy out and complete these sentences in your exercise books…

The three states of matter are __________, __________ and

___________. ___________ and __________ are harder to compress than

__________. Everything is made up of __________. These particles are very

___________.

Extension Homework

The label on a bottle of lemonade shows the following contents… water, citric

acid, flavourings, carbon dioxide, artificial sweetener.

a. Name one substance that is a liquid and one that is a gas. What

Next you are going to investigate what happens when you heat a solid.

substance in the list replaces sugar? Is sugar a solid, liquid or gas?

54


Year 9 Science

Before being heated the metal ball

fits exactly through the hole – but

will it still fit if you heat it first?

Before being heated the metal

bar fits exactly into the gap–

but will it still fit if you heat it

first?

Before being heated the

metal rod fits exactly

between the ends of the

apparatus but as it is heated,

it expands and the scale

measures how much it has got

longer.

When a solid is heated the

particles vibrate even more

and, although they cannot

move around they do vibrate

slightly further apart as you

can see in the diagram.

Now you can see what happens when a liquid is heated.

Fill a round bottomed flask with water and put a rubber

bung in the top.

Mark where the water level is with a marker.

Then place the flask in a large beaker of hot water and

after a few minutes mark where the water level is again.

If the water level has risen then the water in the flask

must have risen when it was heated.

The diagram on the right shows how

the particles of a liquid move with

slightly more energy when they are

heated and this causes them to move

slightly further apart and expand.

55


Year 9 Science

Next you need to learn about how a gas behaves when it is heated.

Place a balloon over the top of a bottle (an

empty bottle which only contains air!)

Now place the bottle in a container of hot

water (so the water will heat up the air

inside the bottle.

If you heat the air enough it will expand and

begin to inflate the balloon.

This is because the particles have been

given even more energy and are moving even

If a gas is heated it will expand.

Also if a gas is cooled down it will

contract – get smaller / decrease

in volume.

If a gas is cooled down enough it

can even turn into a liquid!

Homework 3

1. Write a paragraph about solids using the following words – pour,

shape, expand, water, ice, heat.

2. Draw a diagram showing the particle arrangements in solids, liquids

and gases.

Extension Homework

1. Explain each of the following statements…

a. Heating a metal top on a glass bottle helps you to remove the

top.

b. The Eiffel tower in Paris is smaller in winter than it is in

Summer.

56


Year 9 Science

Next you need to learn about how solids can be changed into liquids, liquids into

gases etc. These are called changes of state.

You need to know the names of these changes of state for your End of Unit

test.

When a solid is heated enough it can

‘melt’ and become a liquid.

When the liquid is cooled again it can

‘freeze’ back into a solid.

When a liquid is heated it can ‘boil’ or

‘evaporate’ into a gas.

When a gas is cooled again it can

‘condense’ back into a liquid.

57


Year 9 Science

Different solids will ‘melt’ at different temperatures.

The temperature at which a solid melts is called its ‘melting point’.

The melting point of ice is 0 o C.

If ice is at a temperature lower than 0 o C

then it will stay as a solid.

If it is heated though it will turn into liquid

water when it reaches 0 o C.

Above 0 o C it will all have already changed

and there will only be liquid water left – no

more solid ice!


Look at the melting points in the table and then answer the questions which

follow.

Substance Melting Point ( o C)

Aluminium 660

Ice 0

Alcohol -117

Iron 1535

Copper 1083

Mercury -39

Polythene 110

Numeracy in

Science

a. Which substance has the lowest melting point?

b. Which substance has the highest melting point?

c. In cold weather which freezes first – water or alcohol?

d. Room Temperature is about 20 o C. Which of these substances may be

liquids at this temperature?

e. If they are being heated from room temperature which one will melt first

– aluminium or copper?

f. What happens if you keep heating a liquid?

g. What happens to the particles when a solid melts?

58


Year 9 Science

Different liquids evaporate or boil at different temperatures.

The temperature at which a liquid turns into a gas is called its ‘boiling point’.

The boiling point of water (turning into steam) is 100 o C.

The particles in a liquid have some energy to

move around but they don’t normally move

very far apart. When the liquid is heated the

particles get a lot of extra energy and some

might jump right out of the container and fly

around – the liquid is turning into a gas – it is

evaporating.

Of course if you take the heat energy away from the particles again – cool the

gas down – then the particles begin to come closer together again and the gas

‘condenses’ back into a liquid.

Density is the word we use to describe how tightly packed the particles are in a

substance.

You can see that the particles in diagram A (solid) are closer together and more

tightly packed than in diagram C (gas). Solids have a higher density than gases.

Below you can see that if there are the same number of particles in a solid and

gas, then the gas will take up more space – have a greater volume!

59


Year 9 Science

So solids are more dense

than liquids and much more

dense than gases.

Liquids are also more dense

than gases.

Homework 4


1. Copy and complete these sentences using one of the words in the

brackets.

Solids are ______ dense than gases. (more/less)

The _______ when a solid melts is called the __________point.

(temperature / time)

The ________ of a liquid is measured in cm 3 . (mass / volume)

When a solid melts it forms a ______. (ice / liquid)

When a liquid freezes it forms a _________. (solid / gas)

Extension Homework

1. Explain why liquids are used inside thermometers.

2. What happens the density of a metal when it is heated?

Next you are going to carry

out an experiment to discover

why the gritter lorries put

salt on the roads in winter.

60


Year 9 Science

Method…

1. Place two thermometers in two beakers.

2. Put 10g of crushed ice in each beaker.

3. Add 0.2g of salt to one of the beakers and stir to mix the ice and salt

completely.

4. Wait one minute and record the temperature on each thermometer.

5. Record the temperature of the ice in each of the beakers each

minute for 20 minutes and watch the ice carefully.

Record your results in a table like this one…

Time (minutes)

Temperature of ice in

beaker without salt ( o C)

Temperature of ice in

beaker with salt ( o C)

Finally plot a graph of temperature against time for each beaker – your teacher

will show you how to do this.

Homework 5

What effect does the salt have on the melting point of ice?

Why do we put salt on the roads in winter?

61


Year 9 Science

Now you need to learn a little more about gases.

The air which is all around you and which you need to breathe in is a gas –

actually it is a mixture of several different gases.

Remember…

When a gas cools down it can ‘condense’ back into a liquid.

Here are some common gases…

Hydrogen

The gases that make up air

Oxygen

Air

Nitrogen

Carbon Dioxide

Helium

Carbon Monoxide

Your teacher may show you how

to make Oxygen gas using a

chemical reaction between

chemicals called Hydrogen

Peroxide and Manganese Dioxide.

The Oxygen gas is then collected

under water.

Homework 6

Draw a diagram of the experiment to make and collect Oxygen and write a

step-by –step method.

62


Year 9 Science

The next section of this topic is about ‘diffusion’ and ‘dissolving’

which are similar in some ways.

First you need to learn about ‘Diffusion’

Imagine you spray some perfume from a bottle of perfume…

Robert Brown was

a famous scientist

who taught us a lot

of what we know

about particle

movement.

The particles of the perfume have energy to move around and they begin to

spread apart and move through the air. That’s why someone on the other side of

the room will be able to smell the perfume after a few minutes.

Use the same idea to explain the following…

You can smell roses from the

other side of the room.

You are not allowed to smoke in

a petrol station.

Homework 7

Look at the newspaper report on an

accident involving a lorry.

Explain why people living 3 miles from

the accident had to be moved.

TANKER CRASH LATEST

The tanker was carrying ammonia.

The gas can affect eyes and

breathing. People living within a 3

mile radius of the crash were moved

from their homes

63


Year 9 Science

Lastly you need to learn about ‘dissolving’.

When some solids are put into a liquid they get smaller and even disappear!

When the solid disappears we say that it has ‘dissolved’.

The liquid with the solid dissolved in it is now called a ‘solution’.

When the sugar goes into the tea the particles of the sugar initially fall to the

bottom but gradually they break apart and move around the tea –spreading out

and dissolving.

Homework 8

Match each of the following descriptions with the correct word…

Solid disappearing in a liquid

Particles moving and mixing

The liquid made when a solid dissolves

solution

dissolving

diffusion

64


Year 9 Science

Next you can try this experiment to investigate ‘dissolving’ and in particular to

find out if the mass of the solution is different from the mass of the liquid and

the solid separately.

Method…

1. Fill a beaker with 200ml of water.

2. Use a balance to find the mass of the beaker and water and record

this.

3. Use the balance to measure out 10g of sugar granules.

4. Add the sugar granules to the water and stir until the sugar has

dissolved.

5. Now use the balance to find the mass of the water and sugar.

Homework 9

1. A purple crystal is put into a beaker of water. It starts to dissolve.

Draw three pictures to show what you think it will look like …

a. After 1 minute

b. After 10 minutes

c. After 1 week.

2. Draw particle diagrams to show what you think happens when…

a. A solid melts

b. A solid dissolves in water

Extension Homework

1. Think about a sugar cube dissolving in water.

What do you think you could do to make it dissolve faster?

Make a list of ideas.

65


Year 9 Science

Next you will be investigating dissolving in more detail – in particular what

things dissolve and what things don’t dissolve and also how we can make things

dissolve faster.

In this first experiment you have to find out which solids will dissolve in water

and which will not.

Method…

1. Half fill a beaker with water.

2. Put one spatula of the first solid powder into the water and stir.

3. Check to see if the solid has dissolved.

4. Repeat with other solid powders – coffee, salt, sulphur, calcium

carbonate, copper sulphate, sugar, iron filings, flour.

5. Put your results in a table like this one.

Name of solid

Does it dissolve in water

(yes/No)

Solids which dissolve are said to be ‘soluble’.

Solids which do not dissolve are ‘insoluble’

Now that you have finished the experiment, try these questions…

1. Which solids are soluble in water?

2. Which solids are insoluble in water?

3. How could you change this experiment to find out which solid is the

most soluble?

Homework 10

Write a paragraph to explain how you could do an experiment to find out if

stirring makes solids dissolve faster.

66


Year 9 Science

In 1949 a man called John Haigh was

charged with murder. He had dissolved

his victim’s body in concentrated

Sulphuric acid. He thought that he could

not be found guilty because there was no

body. But Sulphuric acid does not

dissolve everything. The police found the

victim’s false tooth. The ‘acid bath

murderer’ was found guilty!

In the next couple of lessons you will carry out a few experiments to find out

how we can change the speed of dissolving.

In particular you will investigate the effects of…

Method 1…

Making the liquid hotter

Breaking the solid up into smaller pieces

Method 2…

1. Put 200ml of water at room

temperature in a beaker.

2. Put one spatula of a soluble

solid (eg. copper sulphate) into

the water and start a stopclock.

3. Time until all the solid has

dissolved.

4. Repeat but next time heat the

water first to 30 o C.

5. Repeat again with water at

1. Put 200ml of Hydrochloric

acid in a beaker.

2. Put in one large marble chip

and start the stop-clock.

3. Time until it has finished

dissolving.

4. Repeat but instead of using a

large marble chip, use two

smaller ones.

5. Repeat again with powdered

marble chip.

Your teacher will show you how to draw the results tables to record your

results.

67


Year 9 Science

The factors which affect the speed of dissolving are as follows…

Factor which affects the speed of

dissolving

Temperature of liquid

Particle size of solid

Stirring

How this affects the speed of

dissolving

The hotter the liquid the faster the

solid will dissolve

The smaller the pieces of solid the

faster the solid will dissolve

The more the liquid and solid are stirred

together the faster the solid will

dissolve

The next part of this topic is to look again at ‘Density’.

Remember that solids are more dense than liquids and that gases have the

lowest density of all.

You will now learn how to find out the density of a solid and a liquid.

Finding the density of a regularly shaped solid block is easy – you just weigh it

on a mass balance to find the mass first. Then you multiply its length by breadth

by height to find its volume.

Finally you just use the equation

to use mass and volume to calculate density.

Mass

Density = Volume

But finding the density of an irregular shape (like a stone) is a little more

tricky.

68


Year 9 Science

To do this we copy a method that was first used by a very famous scientist

called Archimedes. You might remember him from Year 8!

Archimedes

Archimedes used a can full to the brim with water and then lowered in the irregularly shaped

stone. This made the water overflow into a measuring cylinder. Archimedes had worked out

that the volume of the water which had overflown would be equal to the volume of the stone

which made it overflow. He thought of this idea when getting into a bath and watching the

water overflow as he got in.

When this happened he shouted ‘EUREKA’ which means ‘I have found it!’

Now look at this question..

Answer…

To find the density of the gold……

Mass = 51.842 g

Final Volume =

19.8 ml

Initial Volume =

17.1 ml

The gold must have a volume of 19.8

– 17.1 which is 2.7 ml because this is

the volume of water it has displaced.

The mass of the stone is 51.842

grams.

Using the equation ..

The volume of water in a measuring cylinder is 17.1 ml.

Density = Mass ÷ Volume

After a stone is lower into it on a piece of string,

the volume becomes 19.8 ml.

The stone has a mass of 51.842 grams.

Density = 51.842 ÷ 2.7

What is the density of the stone?

69


Year 9 Science

What if we want to know the density of a liquid?

Again we just use the equation

Mass

Density = Volume

However to find the mass of a liquid we need to be careful.

When we put it on a Mass Balance to weigh it we have to remember to subtract

the mass of the container it is in.

Let’s say we want to know the density of liquid X.

Step 1: Weigh the empty measuring cylinder

Step 2: Pour in the liquid whose density you are

trying to find and now weigh the liquid and

measuring cylinder together. Next subtract the

mass of the cylinder from the mass of liquid and

cylinder to find the mass of the liquid only.

Finally you can use the equation

Mass

Density = Volume

Step 3: Measure the volume of liquid carefully –

take care to measure the volume at the bottom of

meniscus

Step 4: Calculate the density using the mass and

volume of liquid and the equation for density.

70


Year 9 Science

Here is a summary table describing the particles and densities of solids, liquids

and gases.

Particle Arrangement and

movement

Density

Particle Diagram

Solid

Liquid

Gas

Particles very tightly packed

together and in rows and

columns, only vibrate on the

spot and can’t move from place

to place, strong forces of

attraction between particles

Particles are closely packed

together but are free to move

from place to place in any

direction, force of attraction

between particles still quite

strong but not as strong as in

solids

Particles very spaced out far

apart, move quickly in all

directions, extremely weak

force of attraction between

particles

High

density

Medium

Density

Low

density

So when solids, liquids or gases change state, they take on the properties of the

new state.

For example – when a solid melts and becomes a liquid the particles spacing

increases slightly and the density decreases.

71


Year 9 Science

In the same way when a liquid changes into a gas the average spacing between

particles becomes much larger and the density becomes much lower (particles

much more spaced out).

Homework 11

1. Describe in detail, step by step, how to find the density of a small rock

you might find on the beach. Mention the equation you need to use.

2. Describe in detail, step by step, how to find the density of a liquid.

Mention the equation you need to use.

If you have time your teacher might now spend a lesson showing you how to

make either a hand cream or lip-gloss. If not you are now finished this topic on

‘Matter’ and need to get ready to do your End of Unit Test.

Try these questions to help you revise…

1. Draw diagrams to show the particles in the three states of matter.

2. Which of the states of matter can be squashed? Why?

3. What happens to solids, liquids and gases when they are heated?

4. Explain why the Foyle Bridge is slightly longer in summer than it is in winter.

5. What is the melting point of ice? The boiling point of water?

6. Name the changes of state…

a. Solid to liquid

b. Liquid to gas

c. Gas to liquid

d. Liquid to solid

7. Name the main gases in air.

8. Name three ways of making a solid dissolve faster in a liquid.

9. Look at the diagram and answer the questions that follow.

a. At which

temperature does

the solid dissolve

fastest?

b. What does this tell

us about the effect

of temperature of

the liquid on the

speed of dissolving?

72


Year 9 Science

Careers in Science…

Cosmetic scientists are responsible for developing and making products such as

perfumes, lipsticks, creams and all manner of toiletries. If you particularly want

to develop new fragrances you will need a good nose and a healthy knowledge of

science. Patience and persistence are also needed, as it can take up to 10 years

to become a fully qualified perfumer. This begins with training at one of the few

perfumery schools around the world (the nearest is in France), or within one of

the large fragrance houses.

Although you could one day find yourself developing Beonyce’s next fragrance,

the majority of perfumers work on more ordinary products, like detergents or

shampoo. Starting salaries range from £16,000 to £20,000 a year.

Literacy in Science…

Solid – a material whose particles are tightly packed together in rows and

columns

Liquid – a material whose particles are closely packed but are free to move

around

Gas – a material whose particles are spaced far apart and move quickly all around

Dissolve – a solid which breaks apart in a liquid is said to ‘dissolve’

Diffusion – the movement of particles away from an area where there are lots

of them

73


Year 9 Science

Topic 4 – Magnetism and Electricity

This topic is called ‘Magnetism and Electricity.

First you are going to learn about magnets.

Lots of people think that all metals will stick to magnets

but this is not true.

In fact there are over 80 types of metal but only a few

will stick to a magnet.

Iron and steel are attracted to a magnet.

Michael Faraday was

a famous scientist

who showed us how

to make electricity

by using a magnet.

He once said ‘In

science nothing is

too amazing not to

be true’

There are a few other metals that are also attracted to magnets (Cobalt and

Nickel) but you do not have to learn them off by heart.

Important – not only are iron and steel the

two metals that are attracted to a magnet,

they are also the only two metals that a

magnet can be made out of

Magnets can be different shapes…

Horse-shoe magnet

Bar magnet

74


Year 9 Science

Now you need to find out for yourself which objects will stick (be attracted) to

a magnet.

You will carry out a simple experiment to find this out.

Method…

1. Gather your equipment – bar magnet, various objects including plastic

ruler, wooden pencil, steel paper-clip, iron nail, iron tripod, steel

scissors, plastic pen, paper, glass block.

2. In turn try placing each object close to or touching the magnet and see

if it is ‘sticks’.

3. Write your results in a table like this one…

Name of Object

Wooden pencil

Steel scissors

Plastic ruler

Plastic pen

Does it ‘stick’ to the

magnet (Yes/No)

By doing this experiment you should have been able to confirm that only iron or

steel objects will ‘stick’ to a magnet.

Next you can carry out a short experiment to see how you can turn a piece of

iron or steel into a magnet by using a magnet you already have.

Method…

1. Rub the permanent you already have on the piece of steel

or iron (steel scissors or iron nail).

2. Keep rubbing in the same direction all the time.

3. Test your new magnet by seeing if it can lift some steel

paper clips.

You can demagnetise

the piece of

iron or steel

again by

rubbing the

bar magnet

over it

randomly or

by heating it

over a Bunsen

Burner.

75


Year 9 Science

Your next experiment is to test the strength of a couple of different magnets.

Method…

1. Hold the magnet in place using a retort stand clamp.

2. Place one paper clip at the lower end pole.

3. Hook another paper clip onto the first one.

4. Continue until the magnet can hold no more and all paper clips fall off.

5. Repeat this process with the second magnet.

6. Put all your results in a table like this one.

Type of magnet

Number of paper clips

held

Homework 1

Numeracy in Science

1. A group of pupils did an experiment to test the strength of various

types of magnet and got the following results. Plot a bar graph to

show their results.

Type of magnet

Number of paper clips

held

Permanent steel bar magnet 12

Neodynium magnet 56

Iron core Horseshoe magnet 34

Steel core electromagnet 122

Now you can tell how strong a magnet is.

Next you are going to find out why sailors at sea used to hang magnets from

string to help them figure out their direction.

76


Year 9 Science

The law of attraction between magnets and how compasses work

Pieces of iron and steel will be attracted to every part of a magnet.

However, if you look more closely when they are stuck to the magnet you might

notice that more pieces of iron / steel are attracted to the two ends of the

magnet.

These two ends of the magnet are called its poles – the North pole and the

South pole.

N

It doesn’t matter which type or shape of magnet it

is - all magnets have a North pole and a South

pole.

s

Magnets always attract normal pieces of iron or steel – but what if two magnets

are brought close together?

You need to do a very short experiment to find out. Your teacher will give you

two bar magnets. The North pole on each magnet is indicated by a small groove

at the side. Try this…

Method…

1. Hold the two magnets end to end with the North pole of one next to

the South pole of the other. Observe what happens.

2. Repeat but place the North pole of one magnet next to the North

pole of the other. Observe what happens.

77


Year 9 Science

Hopefully you will have discovered from your experiment that the law of

attraction and repulsion for magnets is as follows…

A North pole next to a South

pole will attract each other.

A South pole next to a North

pole will attract each other.

Now the planet earth is actually a giant magnet

– with a North Two pole North (at the poles North next pole!) to each and a

South pole (at other will South repel pole). (push away)

Two South poles next to each

other will repel (push away)

This law can be summarised like this…

Like poles repel

Unlike poles attract

So now you know the rule for magnets attracting or

repelling each other – the question is how did sailors who

were at sea use this to find out their directions?

The answer which is on the next page might be slightly

surprising…

78


Year 9 Science

The earth itself is actually a giant magnet with a North pole (at the South pole!)

and a South pole (at the North pole!).

Try to imagine that, inside

the earth, there is a giant

magnet.

Its North pole is actually at

the earth’s South pole and

its South pole is at the

earth’s North pole!

If you let a magnet hang freely from a piece of

thread the North pole of the magnet will be

attracted to (and point towards) the earth

magnetic South pole – which of course is

actually at the geographic North pole.

Now, using the law of

attraction and repulsion for

magnets which you have

learned, try to work out what

way a bar magnet would point

if you let it hang from a

thread.

A magnet hanging freely from a thread or

spinning freely on a pin is basically what a

compass is!

This is what sailors used to tell what direction

they were going in.

Wherever the hanging magnet (or compass)

pointed was North.

Once they knew where North was, they could

work out East, South and West.

You can try this out for yourself in class if you have time.

79


Year 9 Science

How to make your own compass

Method…

1. Tie a piece of thread around a bar magnet.

2. Tie the other end of the thread to a retort

stand.

3. Allow the hanging magnet to stop swinging

and note the direction in which the North pole

of the magnet is pointing – this is North!

4. Once you know what direction is North, you can easily work out East,

South and West.

Homework 2

1. Draw a diagram in your exercise book to show the rule of attraction and

repulsion for magnets.

2. Complete the sentences by filling in the blank spaces

Like poles of a magnet __________. Unlike poles __________

Extension Homework

1. Describe how you could make a

magnetic fishing game using the

picture as a clue.

You should first say what

equipment you will need.

Now that you know about the rules for attraction between magnets you need to

look a little more closely at how magnets attract things.

80


Year 9 Science

Magnetic Fields

You may have already noticed that a magnet doesn’t have to actually touch a

steel paper clip for the paper clip to be attracted to it. They just have to be

close. So the magnet seems to have an area around it where it has magnetic

strength.

This is called its ‘Magnetic Field’

The ‘Magnetic Field’ is invisible but you can map it in a couple of different ways.

Try these…

Method 1…

1. Place a bar magnet on a

page.

2. Draw around the magnet and

label the North and South

poles.

3. Sprinkle iron filings lightly

around the magnet.

4. Observe the pattern made

by the iron filings.

Method 2…

1. Place a bar magnet on a page.

2. Place a compass at any pint

around the magnet and

touching the magnet.

3. Note where the compass

pointer is pointing and draw a

dot and the other end of the

pointer.

4. Move the compass to where

you drew the dot and repeat

this process.

5. Do the same but start at

different points around the

magnet.

The magnetic field pattern should look

like the diagram above.

81


Year 9 Science

Homework 3

1. Copy and complete…

A magnet has a ___________ field around it.

The ___________ field is strongest near the two ends of the magnet

which are called the North _____ and the South _____.

A piece of iron can be magnetised by ________ it with a _________.

It can be de-magnetised by _______ it with a Bunsen Burner.

The earth has a magnetic ______ around it.

A North pole _______ another North pole.

A South pole ______ a North pole.

Now you have learned all you need to about permanent magnets. Next you have

to learn about a very special type of magnet called an ‘electromagnet’.

Electromagnets

An electromagnet is made by wrapping some wire around an iron or steel object

(called the core) and then passing electricity through the coil of wire.

You can make one with some wire, an iron nail and a battery or power supply.

Iron nail

Battery

Coils of insulated wire

Switch

Once you have made an electromagnet, you should now carry out a few

experiments to test how you can make it stronger.

82


Year 9 Science

Experiments to investigate the things that can make an electromagnet stronger.

Method 1…

To find out if the Voltage affects the strength.

1. Make the electromagnet by wrapping wire around an iron nail (50

wraps/coils of wire)

2. Connect the electromagnet to a Power Pack.

3. Set the Voltage on the Power Pack to 2 Volts.

4. Dip the end of the electromagnet into a pile of paper clips and lift and

many as possible.

5. Drop the paper clips and count them.

6. Repeat using different voltages 4V, 6V, etc.

7. Put all results in a results table like this one

Voltage on Power Pack (V) Number of Paper Clips lifted

Method 2…

To find out if the number of coils of wire affects the strength.

1. Make the electromagnet by wrapping wire around an iron nail (20

wraps/coils of wire)

2. Connect the electromagnet to a Power Pack.

3. Set the Voltage on the Power Pack to 8 Volts.

4. Dip the end of the electromagnet into a pile of paper clips and lift and

many as possible.

5. Drop the paper clips and count them.

6. Repeat but first wrap the wire around the iron nail 30 times.

7. Repeat changing the number of coils to 40, 50 , 60 etc

8. Put the results in a results table like this one

Number of coils of wire Number of Paper Clips lifted

Hopefully in these experiments you will have found that…

The higher the voltage the stronger the electromagnet is

and

The more coils of wire, the stronger the electromagnet is

83


Year 9 Science

So now you know that there are several ways of making an electromagnet

stronger – higher voltage, more coils of wire and you can also make it stronger

by using an iron core to wrap the wire around.

But where are electromagnets used?

Electromagnets are used a lot in many places….

Computer hard disks, speakers on MP4 players,

iPads, MRI scanners, door-bells, scrap-yards

They are actually really important in everyday

life and are used much more often than

ordinary magnets.

Homework 4

1. A group of pupils did an experiment to see how the strength of an

electromagnet was affected by the number of coils of wire.

They got the following results…

Number of coils

of wire

10 2

20 5

30 6

40 8

50 11

60 15

70 22

80 28

90 37

100 48

Number of paper

clips lifted

Numeracy in

Science

Plot a scatter graph of these results and draw a line of best fit.

84


Year 9 Science

You have now finished learning about magnets and magnetism.

You will now be learning about the second half of this topic.

eel leek tree city

Yes, you guessed it – Electricity.

Electricity is the flow of tiny particles in wires called electrons’.

Electricity is a form of energy. We can this energy from a battery or from the

mains (sockets and plugs).

Can you think of anything in your home that uses batteries?

In science we use symbols for the equipment we use when we make electrical

circuits.

Name of equipment and Symbol for equipment

picture

Battery

Bulb

Ammeter

Voltmeter

Switch

We use these circuit symbols when drawing electrical circuits.

85


Year 9 Science

Can you figure out what is in these circuits?

A

V

Before you carry out experiments into electricity, you should practice building

these two simple circuits.

Next you are going to build a simple circuit and leave a gap. You will then put

different materials into the gap to find out which materials will allow electricity

to pass through them – which materials ‘conduct’ electricity.

Method…

Homework 5

1. Which of the following are

conductors and which are

insulators?

Steel, copper, wood,

plastic, aluminium, paper,

glass, brass, gold, rubber,

1. Build an electric circuit with a

battery, bulb, switch and a gap

between 2 crocodile clips.

2. Place each test material between

the clips and see if the bulb lights

up or not.

3. Put your results in a results table

like this…

Name of

material

Does the bulb light

up / Does it conduct

electricity?

Did you know that there is only one material that is not a metal that conducts

electricity - graphite

86


Year 9 Science

At this point you need to learn a few key words about this section.

Literacy in Science

Current – the amount of electricity that is flowing in a circuit

Ammeter – a device that measures how much electrical current is flowing

Voltage – the amount of energy the battery is giving out

Voltmeter – a device that measures the voltage

Conductor – a material that lets electricity flow through it

Insulator – a material that doesn’t let electricity flow through it

Now you can make an electric quiz game if you have time…

You will need…

A4 card sellotape tin-foil

Method…

1. Punch holes at the sides of the card – 5 on each long side near the

edges.

2. Write questions beside each of the holes on the left edge and answers

beside the holes on the right hand side (but not in the correct order)

3. On the back of the card, join up each question with its correct answer

with a thin strip of tin-foil (Note – it is important that each strip of

tin-foil is covered completely with sellotape before another strip is

added)

4. Cover the back of the card with a second piece of coloured card.

87


Year 9 Science

Homework 6

1. Copy and complete

When a bulb lights up in a circuit it shows that an electric ________is

flowing. For an electric _______ to flow there must be a _____

circuit with no ____ in it.

2. Explain what is meant by

a. A conductor

b. An Insulator

3. Draw and label the circuit symbols for

a. A battery

b. A bulb

c. An ammeter

d. A Voltmeter

Next you need to know the difference between ‘series’ and ‘parallel’ circuits and

be able to interpret them.

A ‘series’ circuit is one where there is only one path – so there is never any

choice of paths for the electricity. Below is an example of a series circuit.

In this ‘series’ circuit, the

electricity flows from the

battery through the first bulb,

through the switch and through

the second bulb back into the

battery for more energy. At no

point does the electricity have

any other possible path.

88


Year 9 Science

A ‘parallel’ circuit is one in which there is a choice of two or more paths at some

point in the circuit. Below is a diagram of a ‘parallel’ circuit.

A

In this ‘parallel’ circuit the electricity

flows out of the battery and towards

the first bulb.

However at point A the electricity has

a choice of whether to travel across

to the first bulb or down towards the

second bulb.

If there is a choice of pathways at

any point on the circuit, then the

Now you need to be able to figure out what happens in series and parallel

circuits. Look at this circuit diagram and answer the questions.

Switch 2

Switch 1

1. Which switch(es) need to be

pressed for Bulb A to light

up?


pressed for Bulb B to light

up?


pressed for Bulb C to light

Now look at this circuit diagram and answer the questions.

B

A


pressed for Bulb A to light

up?


pressed for Bulb B to light

up?

89


Year 9 Science

Homework 7

1. Copy and complete

In an electric circuit tiny ____________ move through the wires.

If all the current goes on the same path through the whole circuit, it is

a ________ circuit.

If the current can split up between two pathways, the circuit is

__________.

Extension Homework

1. Draw the following circuits…

a. A series circuit with one battery, two bulbs and two switches in

series.

b. A circuit with a battery, a switch and 2 bulbs in parallel.

Now you are going to practice building some circuits.

You should gather the correct equipment which your teacher will provide and

build these circuits.

A

B

C

90


Year 9 Science

Homework 8

1. Look at the circuit diagrams and answer the questions that follow.

a. In circuit B which bulb will light up if the switch is closed?

b. In circuit C are the bulbs in series of parallel?

c. In circuit D – if one bulb is broken, will the other bulb still work?

d. Are the bulbs in circuit A in series or parallel?

The last thing you need to learn about in this topic is the plug.

The brown wire is called the ‘live’ wire – it

carries the electricity from the socket

into the appliance (eg. the television).

Just think you have brown hair and you’re

alive so the brown wire is the ‘live’ wire.

The blue wire is called the neutral wire –

it carries the electricity back out of the

appliance.

The green and yellow wire is called the

earth wire – it carries electricity into the

‘earth’ to make sure it does not go

through a person and electrocute the

person.

91


Year 9 Science

Next you are going to learn about another type of electricity. This type does

not flow like ‘current’ electricity. It normally stays still because it has no path

to flow but then if a path becomes available it might suddenly ‘jump’ out to

follow the path. It is called ‘static electricity’

Static Electricity

Have you ever taken off a jumper and felt it crackle? Or stepped out of a car

after a journey and got a slight shock as you touched the car door?

The jumper and the car have become charged with static electricity.

Lightning is caused by a similar effect.

There are two types of electric charge…

Positive

negative

There must be two types of charge because there are two types of force

(attraction and repulsion) which are caused by electric charges.

There is a simple experiment which can show you the two types of electric

charge…

In the first diagram an acetate rod is rubbed and brought close to a polythene rod

which has also been rubbed. The two rods attract one another. In the second

diagram two polythene rods which have been rubbed are brought together and

they repel one another.

92


Year 9 Science

These two simple demonstrations show that…

there must be two types of electric charge – positive and negative –

because there are two types of force – attraction and repulsion.

Objects can become charged by rubbing (friction)

So how do objects become charged by friction (rubbing)?

Well everything is made of atoms.

An atom is made up of a tiny positive nucleus (made of protons and neutrons)

surrounded by negative electrons orbiting this nucleus.

When you rub an acetate rod with a cloth, electrons move from the acetate rod

onto the cloth.

The cloth now has extra negative electrons – making it negatively charged.

The rod now has fewer negative electrons – making it positively charged.

Acetate

rod

Cloth

93


Year 9 Science

It is important to remember that when an object gains electrons it becomes

negatively charged and when an object loses electrons, it becomes positively

charged.

Charged objects can either attract or repel other charged objects and the rule

is a s follows…

Like (similar) charges repel and Unlike charges attract

It is a little like the rule for magnetic poles!

Charged objects can also attract uncharged objects.

This is slightly harder to explain.

Here is the explanation…

When a positively charged rod is

brought next to a piece of aluminium,

the free electrons in the foil are pulled

towards the rod by its positive charge.

This makes a surplus of electrons on

the foil close to the rod which means

fewer electrons at the other side of

the foil. This means the other side of

So the top of the foil is attracted to the rod but the other edge of the foil is

repelled. The force of attraction is stronger than the force of repulsion (because

the attracting forces are closer together than the repelling force is). Overall there

is a resultant force of attraction so the foil is attracted to the rod.

There are other examples of this like a polythene rod attracting a stream of water

94


Year 9 Science

There are some useful applications of Static Electricity…

1. Smoke precipitators in power stations

How it works…

Smoke contains lots of

Use of Static Electricity

small particles which

pollute the atmosphere

but these can be

removed before they

leave the chimney.

The smoke particles

gain a negative electric

charge as they pass

through the negatively

The chimney also has positively charged plates which attract the negatively charged charged grid. smoke They are

particles which stops them from leaving the chimney. The particles can then then be repelled collected by from the

these positively charged plates.

gird (like charges

2. Paint-spraying

Use of Static Electricity

In an electronic spray-paint gun, the

droplets of paint become charged before

they leave the gun. Because the droplets all

have the same charge they all repel one

another so the paint spreads out into a very

fine mist (like charges repel).

The car is charged with the opposite charge

95


Year 9 Science

Now that you know some uses of static electricity, you also need to know some

examples of where static electricity can be dangerous…

Danger of Static Electricity

Danger of Static Electricity

1. Fuelling aircraft

When large petrol tankers are used to refuel aircraft, the friction of the

fuel rubbing on the inside of the pipe can cause a spark which can then

ignite the fuel and cause a fire or

explosion. To avoid this we can

connect a cable from the aircraft

to the earth (earth the aircraft)

to carry any charge away into the

round instead.

2. Lightning

In a thunderstorm a cloud

with a lot of charge built up

on it might come close to a

tall object like a building or

a tree. If this happens the

charge might come through

the air to earth. This ionises

the air particles and allows

electricity to pass through the air. A lightning flash happens when a large

amount of charge is re-joined with the air particles that have lost

electrons.

Static Electricity as a nuisance

Now that you know some uses and some dangers of static electricity, you also

need to know some examples of where static electricity can be a nuisance…

1. Clothes stick together when they come out of a tumble drier

2. Getting a shock from walking on a nylon carpet

3. TV screens and computer screens get a build-up of static and need to be

cleaned with anti-static cloths.

96


Year 9 Science

You are now finished this topic and you need to prepare for your end of unit

test.

Use the mind map below to help you revise.

You will only need to revise ‘static electricity’ if your teacher tells you.

Bar magnets and

horseshoe

magnets

Magnetic Field

patterns and how to

draw them

Electrical circuits

– series and

parallel

Topic 4

‘Magnetism &

Electricity’

How to make a

magnet and

demagnetise it

Symbols for

electrical

equipment

Electromagnets

Law of

attraction and

repulsion for

bar magnets

97


Year 9 Science

Topic 5 – Environment

Your next topic is ‘Environment’. In this topic you will be learning about where

animals and plants live and how they survive. You will also be learning about what

animals eat and how they get energy. Finally you will have the opportunity to

carry out your own field study and learn about some of the equipment scientists

use to study animals and plants.

First you need to learn the meanings of a few key words…

The place where an animal or plant lives is called a ‘Habitat’.

The surroundings and conditions in which an animal lives is called its

‘environment’.

To survive in their ‘habitats’ animals and plants need certain things…

Things which animals need to survive

Food

Water

Warmth

Air (Oxygen)

Shelter

Protection

Things which plants need to survive

Water

Light

Carbon Dioxide

Animals need to be suited to their habitat in order to survive.

For example – a camel would not survive at the North Pole

and a Polar Bear would not survive in the desert!

Hey, fancy

swapping

habitats?

Scan the QR code

to watch a video

about Adaptation.

98


Year 9 Science

When an animal or plant is well suited to living in its habitat

we say it is ‘adapted’ to the habitat.

For example a Polar Bear is adapted to live in the Arctic because

it has lots of fur to keep it warm, it is white to camouflage itself

Charles Darwin was

against the snow, it has sharp claws and teeth to catch its food and

a famous scientist

it has large feet to stop it sinking in the snow or cracking the ice!

who taught us

about how animals

Now try these questions about ‘Adaptation’…

adapt in order to

survive.

1. Write 5 ways in which each animal is adapted to survive in its habitat.

a. Camel

b. Tiger

c. Shark

d. Polar Bear

e. Eagle

2. Match up the following living things with the correct habitats…

Moss

Trout

Squirrel

Frog

Dandelion

Hawthorn tree

Pond

Hedge

Path

Stream

Wall

Wood

3. List some of the conditions which make life difficult in the following habitats.

a. Stream

b. Hedge

c. Seashore rock pool

d. Mountain

Extension Question

Write a letter to your pen-friend on the planet Zog.

Explain to her what conditions are like on earth.

99


Year 9 Science

Homework 1

1. Explorers have been able to survive in very bad conditions. How

have they stayed alive …

a. In outer space

b. At the bottom of the sea

c. In the frozen arctic

Extension Homework

1. Choose: a. an insect b. a bird c. a mammal

For each of your choices, say where it lives, what it feeds on and

how it is adapted to its habitat.

Charles Darwin was a very famous

scientist who developed the theory of

evolution. He believed that animals

need to adapt in order to survive –

particularly if their habitat changes.

He taught us that the species of

animals which thrive best are the ones

Now that you know what a ‘habitat’ is you are going to use some special

equipment to carry out your own ‘Field Study’ – a field study is where we go

outside and take measurements in an environment and perhaps even collect some

animals to investigate them more closely.

100


Year 9 Science

First let’s look at some of the equipment you might need…

Anemometer –

measures wind

speed

Beating Tray –

collects leaves and

insects from trees

pH meter –

measures the pH of

soil or water

Pit fall trap –

captures small insects and

spiders

Pooter –

collects small

insects

Quadrat –

helps estimate the

number of living things

in a certain area

Sweep Net –

collects insects from bushes

Thermometer

measures

temperature of

air , soil or water

Now that you know more about the equipment, you are ready to carry out a real

‘Field Study’

To do this you will work in groups. You must then share results with your class

so that everyone can complete the results tables below and on the next page…

Results Table 1 – Environment Measurements

Location Wind Speed (m/s) Temperature ( o C) pH of soil/water

A-

B-

101


Year 9 Science

Results Table 2 – Invertebrates

Location Name of Invertebrate Number of invertebrates found

A-

B-

You might need to use a key to identify some of the invertebrates.

You will more about keys

later in this topic.

Good Luck!

Homework 2

Draw a bar chart to show the numbers of invertebrates found by the class

during the field study.

Next you are going to learn more about how some animals have adapted to

survive in their habitats.

There are many different ways in which plants and animals have adapted or

changed over time in order to better survive – to find food or hunt, to avoid

being eaten, to keep warm and safe.

On the next page you will at some examples…

102


Year 9 Science

Now look at the table which outlines some adaptations of other animals…

Name of animal / plant

Tiger

Cactus

Eagle

Antelope

Hedgehog

Adaptations

Stripes for camouflage so it can hunt / sharp claws and

teeth to catch its prey / strong legs to outrun its prey /

eyes on front of head for judging distance

Waxy to avoid letting water escape / long roots to find

water underground

Eyes on front of head for excellent eye-sight / sharp

claws and beak to catch prey

Colour like its habitat to camouflage / strong legs to

outrun its predators / big ears to hear predators coming

Prickly fur to keep predators away / claws for finding

food (insects)

Bat Big ears for hearing echoes to find its way in the dark /

sharp claws and teeth for catching its prey

103


Year 9 Science


1. Why do arctic foxes have white fur in winter but their fur then turns

dark in summer time?

2. What special feature do skunks have and how does this protect them

from predators?

3. Why do polar bears have …

a. Large padded feet

b. Sharp claws

c. White fur

d. Strong legs

e. Eyes at the front of their heads

Homework 3

Design your own ‘animal’ or ‘plant’ for a habitat on an alien planet.

Draw a coloured picture of the animal / plant you have designed and label each

feature explaining how it helps the animal / plant survive in the alien habitat.

Extension Homework

Some pupils did a survey of a small woodland habitat. They identified and

counted all the trees. The table below shows their results.

a. Draw a bar chart of these results.

b. Which were the 2 most common trees in the woods?

Name of tree Number in woods

Ash 8

Beech 15

Birch 20

Holly 2

Oak 4

Numeracy in

Science

Next you are going to learn about the special ways that some animals have to

survive through the winter.

104


Year 9 Science

Hibernation

In summer time there are lots of greenfly on the rose bushes. But where do the

greenfly go in winter?

They lay eggs with a tough coating to

survive the winter cold. The old greenfly

then die and the new greenfly hatch in the

spring.

Ladybirds feed on greenfly so in the winter

they have nothing to eat.

So ladybirds hibernate in the winter inside

crack in trees’ bark or under dead leaves.

Ladybirds hibernating inside dead leaves

Some other animals that hibernate in winter

are…

Snake

Badger

Squirrel

Bumble bee

Bear

Another special way in which some animals survive the winter is ‘migration’.

You will learn about this on the next page…

105


Year 9 Science

Migration

Migration means leaving one habitat and

moving to another in order to survive. Some

animals do this during the winter months in

particular to avoid the harsh, cold

conditions in their usual habitat. Normally

they move southwards where it is warmer.

Above is a map showing how

swallows move south from Ireland

in the winter in order to survive

the winter cold. They fly to South

Africa where the winter is much

warmer than it is in Ireland.

To the left is an image of the

swallows migrating.

Some birds might also fly to

Ireland in the winter!

Where do you think they are

coming from?

The answer is at the bottom

of the page.


1. How does each of these animals pass the

winter – hedgehog, swallow, greenfly,

Berwick’s swan?

2. How do squirrels prepare for their

hibernation?

Homework 4

Numeracy in Science

Different climates have different patterns of rainfall

throughout the year. Plot 2 graphs using the following sets

of rainfall data.

Month Rainfall in Location A (mm) Rainfall in Location B (mm)

January 55 60

March 30 170

May 15 23

July 0 80

September 20 90

November 50 140

Answer:

Birds which

migrate to

Ireland in the

winter are

coming from

further north

where it is

even colder

than in

Ireland.

106


Year 9 Science

Food Chains

Now you need to learn how animals and plants depend on each other in their

habitats – this is called ‘interdependence’.

Mainly animals and plants need each other for food – in other words some

animals eat plants for their energy and some animals eat other animals for their

energy.

A diagram which shows what eats what is called a food chain.

Here is an example…

All food chains must start with a plant – in this case the plant is grass.

The grass gets its energy from the sun.

The arrows mean ‘is eaten by’.

So the grass is eaten by the grasshopper, the grasshopper is eaten by the

mouse and the mouse is eaten by the owl.

Another way of describing the arrows is to say that they indicate the direction

of the flow of energy – ie. the energy inside the grass goes into the grasshopper

when it eats the grass.

Here is another example of a food chain…

This time the plant is

maize (corn). The corn

is eaten by the locust so

Let’s its energy look at goes one into more the

food locust. chain… The locust then

is eaten by the lizard

and finally the lizard is

eaten by the snake.

107


Year 9 Science

This time the sun itself is included although you don’t have to do this!

The plant is the algae – in a food chain the plant is sometimes called the

‘producer’ because it produces its own food from the energy of the sun.

The algae is then eaten by the mosquito. The mosquito is the first ‘eater’ in the

food chain and so it is called the ‘primary consumer’ (which means ‘first eater’).

The mosquito is then eaten by the frog – the frog is called the ‘secondary

consumer’ (second eater)

Finally the frog is then eaten by the lizard – the lizard is called the tertiary

consumer (third eater).

Because the lizard is at the end of the food chain it is also known as the top

predator.

The general rule for all food chains can be shown by this…

Producer Primary Consumer Secondary Consumer Tertiary Consumer

(Plant) (First animal) (second animal) (third animal)


1. Which is the producer?

2. Which is the primary consumer?

3. Which is the secondary consumer?

4. Which is the top predator?

5. Where does the deer get its energy

from?

6. Where does the grass get its energy

from?

108


Year 9 Science

Homework 5

Look at the food chain and answer the questions which follow.

1. Which organism in the food chain is a producer?

2. Which are consumers?

3. Which one is the top consumer?

4. Which two are predators?

5. Which one is the primary consumer?

6. Where does the phytoplankton get its energy from?

Extension Homework

Make food chains out of each group of living organisms…

a. Thrush, cabbage, caterpillar

b. Slug, hedgehog, lettuce

c. Tiny plants, fish, water fleas, tadpoles

d. Greenfly, blackbird, ladybird, rosebush

Next we are going to look at food webs.

A food web is really just several food chains interconnected. It is more realistic

because most animals have more than one thing in their diet. For example – a lion

does not only eat antelope; a lion will also eat zebras and even giraffe and

elephants!

Look at the food web on the next page…

Scan the QR code to watch

a video on Food Chains.

109


Year 9 Science

Snake

Hawk

[Type a quote from the

[Type a quote from the

document or the summary of

document or the summary of

an interesting point. You can

an interesting point. You can

position the text box

position the text box

anywhere in the document.

anywhere

Use the Drawing Shre in the document.

Tools tab to

Use the Drawing Tools tab to

change the formatting of the

pull quote text box.]

Frog

Marsh Grass

Grasshopper

Cricket

Cattail

In this food web above there are 2 producers (Remember – producers are

plants because they ‘produce’ their own food from the sun’s energy.

The 2 producers are ‘Marsh Grass’ and ‘Cattail’.

To find the ‘primary consumers’ you need to look at the first animals in the food

web – these will be the animals that eat the plants. In this food web the

‘primary consumers’ are grasshopper and cricket. These animals are also called

‘herbivores’ because they eat plants only.

Next you look for the ‘secondary consumers’. These are the animals that eat

the ‘primary consumers’. In this food web the secondary consumers are shrew

and frog. Secondary consumers are also called ‘carnivores’ because they eat

meat (other animals).

Finally the snake and the hawk are tertiary consumers because they eat the

secondary consumers. They are also carnivores. These two animals would also be

called the ‘top predators’ because nothing else eats them!

This is all pretty complicated so you should take some time and learn the

meanings of some key words at this stage in the unit.

110


Year 9 Science

Literacy in Science

Producer – the plant in a food chain or food web which produces its own food

Primary Consumer – the first eater or first animal in a food chain or food web

Secondary Consumer – the second eater or animal in a food chain or food web

Tertiary Consumer – the third eater or animal in a food chain or food web

Herbivore – an animal which eats only plants

Carnivore – an animal which eats only meat (other animals)

Omnivore – an animal which eats plants and meat (like we humans do!)

Predator – an animal which has to hunt its food (always a carnivore)

Prey – an animal which gets hunted and eaten

Top Predator – an animal which does not get eaten by any other animal

You should study these key words before you continue in this unit.

Homework 6

Learn the meanings of all the key words in the box above.

The teacher might test you on these meanings in your next lesson!

Once you have learned these key words you are ready to try some questions

about food webs.

Try the questions on the next page as practice…

111


Year 9 Science

Questions on Food Webs

1. Look at the food web and answer the questions that follow.

a. Name the producers in the food web.

b. Name all the primary consumers.

c. Name all the secondary consumers

d. Name the top predators.

e. What do skunks eat?

f. What do snowy owls eat?

g. What gets eaten by wolverines?

h. If all the porcupines died from disease, how do you think the number of

ermines would be affected? Why?

i. If all the ermines died from disease how do you think this would affect

the number of porcupines and also the number of snowy owls?

j. Name all the herbivores in the food web.

k. Name all the carnivores in the food web.

112


Year 9 Science

Questions on Food Webs (continued)

2. Look at the Food Web and answer the questions that follow.

a. Name the producers in the food web.

b. Name all the primary consumers.

c. Name all the secondary consumers


e. What do baboons eat?

f. What do African skunks eat?

g. What gets eaten by leopards?

h. If the number of fiscal shrikes went down because of disease what do

you think would happen the number of grasshoppers and the number of

skunks? Why?

i. Name all the herbivores in the food web.

j. Name all the carnivores in the food web.

113


Year 9 Science

Questions on Food Webs (continued)

3. For each of the food webs below identify the …

a. all the producers

b. all the herbivores

A

c. all the carnivores

d. all the predators

B

C

Extension Work

For Food Web A above…

1. What gets eaten by the spider?

2. What does the shrew eat?

3. If the number of wood mice went up what would happen the number of

snails?

For Food Web B above…

4. If the number of frogs decreased because of disease what would

happen the number of grasshoppers? Why?

114


Year 9 Science

Homework 7

Look at the food web below and answer the questions that follow.

a. Name all the producers in this food web.

b. Name all the primary consumers

c. Name all the secondary consumers.


e. What do water fleas eat?

f. If the number of crabs rose what would happen the number of octopus?

Explain why.

115


Year 9 Science

Next you are going to learn about keys and how we use them in science.

Earlier you look at filed study equipment and you might have got a brief look at

a key to identify some small animals.

You will now get to practice using keys and even constructing your own keys.

First look at this simple key and imagine you had to use it to identify some small

animals collected during a field study.

Has the mini-beast got legs?

Yes, has it got wings?

No, has it got a shell?

No, has it got more

than 8 legs?

Yes, is it active

at night?

No

Yes

Yes

No

Yes

No

Worm

Snail

Centipede

Spider Moth Butterfly

Basically you would take each small animal (mini-beast) in turn and while

looking at it answer the questions and follow your answers until you arrive

at the correct name for that animal. Now try using this simple key to put

each form of transport in the correct group…

Wheelbarrow Lorry Bicycle Horse Canoe

116


Year 9 Science

Homework 8

Look at the pictures of some mythological creatures and then use the key below to

identify them…

A

B

C

E

D

F

Does the creature have 4 legs?

Yes

No

Does the creature have

more than one head?

Yes No

Does the creature have a horn on its head?

Yes

No

Are the heads from

different animals?

Does the creature

have wings?

Yes No

Cyclops

Medusa

Yes

No

Pegasus

Centaur

Chimera

Hydra

117


Year 9 Science

Extension Homework

Look at the dinosaurs above and use the key below to identify each one…

Does it walk on four legs?

Yes

No

Does it have a large

crest on its head?

Does it have a trumpet shape

on the back of its head?

Next you can look at another type of key which involves pairs of sentences

Yes

No

Yes No

rather than a spider diagram.

The one below is for different types of leaf…

Triceratops

Does it have

armoured plates

on its back?

Parasaur

Tyrannosaur

Yes

No

Stegasaur

Brachiosaur

118


Year 9 Science

Now you can look at a different type of key which involves using pairs of

sentences to identify different things. Look at this key to identify different

types of leaf…

Key for Leaves

1

Leaf divided into leaflets……………………...Go to 2

Leaf not divided into leaflets……………....Go to 4

A

B

2

Leaflets attached to central point….…Buckeye

Leaflets attached at several points…….Go to 3

C

3

Leaflets taper to pointed tips………………..Pecan

Oval leaflets with rounded tips………..……Locust

D

E

4

Veins branch out from central point…...Go to 5

Veins branch off in middle of leaf……….Go to 6

5

Leaf is heart shaped………………………….……Redbud

Leaf is star shaped………………………….Sweet Gum

F

G

6

Leaf has jagged edge………………………………….Birch

Leaf has smooth edge………………………….Magnolia

In this type of key you always start at the first pair of sentences (1). You then

look at one leaf and choose which of the sentences in 1 is correct for this leaf;

then simply follow the instructions (always referring back to the leaf you are

identifying first) until you arrive at the name of that type of leaf.

When you have the name of the first leaf, you simply repeat this process for each

of the other leaves in turn.

On the next page you can see how both keys can be used to identify some types of

flower.

119


Year 9 Science

Try each type of key in turn to see how they work…

On the next few pages you can practice using some keys and even have a go at

creating your own keys…

120


Year 9 Science

Look at the pictures of different types of plants below.

Choose any six of the plants and then design and draw out a ‘spider diagram’

key to identify the plants you have chosen.

Now you have finished studying how to use keys, the next thing you need to

learn is ‘predator-prey diagrams.

121


Year 9 Science

There is a clear relationship between animals which eat or get eaten by

other animals.

Let’s think about lions and zebra to try to figure out the relationship.

Lions eat zebras.

Lions are predators and zebras are their prey.

Normally the numbers of lions and zebras in an area will stay pretty

constant – the numbers might change a little but not usually by very much.

But what if lots of lions were killed by poachers?

Then suddenly not as many zebras would be getting eaten so the number of

zebras would probably rise.

Of course this rise in the number of zebras would mean that the surviving

lions would have plenty to eat and so the number of lions will eventually rise

again.

Now there would be more lions eating zebras so the number of zebras goes

down.

But of course that means that there are now fewer zebras for the lions to

eat so some may starve and the number of lions then goes down.

You should now see how the animals are dependent non each other. This can

be shown in a ‘predator-prey’ diagram.

You have now finished Food Webs, keys and predator prey diagrams.

The last thing you need to learn about in this topic is how living organisms

disappear after they have died.

122


Year 9 Science

In an earlier topic you learned about the difference between living things and

non-living things.

Have you ever wondered why there are not dead animals all over the place?

Where do their bodies go?

Well, strange as it might seem the answer

can be found by thinking about why an

apple goes brown or why food goes off!

Apples go brown, food goes off and dead

animals disappear – all because of tiny living organisms called microbes.

These microbes are all around us – in the air, water etc.

There are three types of microbe – bacteria, fungi and viruses.

Bacteria Virus Fungus

So when microbes make the bodies of dead animals ‘rot away’ and disappear,

that is good as it prevents the spread of disease.

But when microbes make food ‘rot away’ it is not so good!

How can we prevent or at least slow down microbes making foods go bad?

To answer this we need to recall that microbes are living thigs too!

That means that they need certain things in order to survive (and make the

food go bad). Microbes need Oxygen, warmth and moisture.

123


Year 9 Science

So to stop microbes from making our food go bad we need to keep the food in

certain conditions – cool and dry!

This is why we normally store food in

cold fridges or in dry cupboards.

Louis Pasteur

was a famous

French scientist

who taught us a

lot about

microbes.

Homework 8

1. Which conditions do you think stop the following foods from going bad?

a. Frozen sweetcorn

b. Dried peas

c. Vacuum packed bacon

d. Canned peaches

e. Packet of crisps

Extension Homework

2. Many foods have a ‘use by’ or ‘best before’ date on them. Make a list of

foods in your house that have these on them. In your list also write

down how long each food can ‘last’ from when you bought it (You might

need help here from the person who bought the food).

3. Canned foods and dried foods don’t always have a ‘use by’ date. Why

not?

4. Sometimes dead bodies do not decompose – woolly mammoths in frozen

Siberia and human bodies in acid turf bogs. Explain why.

124


Year 9 Science

You have now finished this topic and you need to prepare for your end of Unit

Assessment.

Look at the revision list / check list below to help you prepare.

Content

I know what habitat and

environment mean

I know the main field

study equipment

I know what is meant by

adaptation

I know how some

animals have adapted to

survive in their habitat

I know what is meant by

hibernation and

migration

I know what food chains

are

I know what producers,

consumers and

predators are

I know what herbivores,

carnivores and

omnivores are

I know how to use keys

and predator-prey

diagrams

I know what microbes

are – three types

bacteria, virus and fungi

I know what conditions

microbes need to

survive

Red Light =

don’t know it yet

Amber Light =

getting there…

Green Light =

Know it!

125


Year 9 Science

Literacy in Science

You have already learned many of this unit’s key words earlier but here are

some more you need to know too.

Habitat – the place where an animal or plant lives

Environment – the conditions in which an animal or plant lives

Adaptation – the ability of a species to change over time in order to survive in

a changing environment

Pooter – a small container used to gather (suck up) small invertebrates

Quadrat – a grid used to estimate numbers of species in a large are like a field

Beating tray – used to collect small animals (bugs) from trees

Sweep net – used to collect small animals (bugs) from bushed

Hibernation – what some animals do in the winter to survive (like going to sleep)

Migration – moving from one place to another far away in order to survive

changing conditions

Microbe – very small living organism

Bacteria, Virus and Fungi – the 3 types of microbe

Careers in Science

Microbiologist

A microbiologist is a scientist who studies

microscopic living organisms including

bacteria, algae, fungi and viruses.

Sometimes they study these because the

micro-organisms are causing disease to

humans, animals or plants.

You are now ready to do your Assessment on the topic ‘Environment’. Good Luck!

126


Year 9 Science

End of Unit Assessment

Part A

Choose six animals and design your own key to identify these animals.

Choose six plants and design you own key to identify these plants.

10 marks

Part B

Choose a habitat and research at least 10 animals which live in this habitat,

Using these animals design a food web to show how they depend on one another.

From the food web draw 3 food chains.

(Hint: Some habitats you might choose are… woodland, forest, ocean, desert,

pond, African plains, river)

10 marks

Part C

Pick one predator and its prey from your food web and draw a predator-prey

phase diagram to show how their numbers are dependent on one another.

5 marks

Now describe all the ways you can think of in which animals in a certain habitat

depend on one another. To do this you might need to carry out some research on

how animals might compete for food or how animals sometimes help one another

for the benefit of both of them.

5 marks

Total Marks for this assessment = 30 marks

127


Year 9 Science

Topic 6 – Elements, Mixtures and Separations

In this topic you will be learning about atoms and elements, mixtures and

compounds. You will also learn about different ways to separate mixtures.

Before you start remember back to when you studied

Topic 3 – Matter.

You learned that all things are made up of tiny particles.

In solids the particles are arranged in rows and columns

and are close together, in liquids the particles are still

close but can move and flow and in gases the particles are

spaced very far apart and move quickly all over the place.

The diagram to the right shows this.

These particles that everything is made up of are called

‘atoms’.

Everything in the whole universe is made up of these tiny

atoms.

So if everything is made of atoms – how come there are

so many different substances and materials?

The answer is… there are different types of atoms – in

fact it turns out that there are just over 100 different types of atom.

You can find the names for all these different atoms in the ‘Periodic Table’

which you will earn more about in Year 10.

We normally draw atoms as coloured circles – with different colours

representing different types of atom.

These atoms are

arranged together in

rows and columns so

this material is a solid.

These atoms are not

arranged together in

rows and columns but

are still close so this

material is a liquid.

These atoms are very

far apart so this

material is a gas.

128


Year 9 Science

What you should also notice about the atoms in the diagrams is that, the atoms

in the first diagram are different from those in the other two –in fact the

atoms in each of the 3 diagrams are different from those in the other two

diagrams. So not only are the states of matter different but the actual

substances are also different.

This material could

be a solid you know

like Copper.

This material

could be a liquid

you have heard of

like Iodine.

This material could

be a gas you know

like Oxygen..

The substances above are all made of atoms.

Each substance is different from the other two because it is made of a

different type of atom.

In each substance all the atoms that make it up are the same as each other.

We say that each substance is ‘pure’

‘Pure’ substances are called ‘elements’

Which of these 4 substances are ‘elements’?

Remember – for a substance

to be an element it has to be

pure – that means that all

the atoms which make it up

have to be of the same type.

So which substances are

elements? – Which

substances are pure? –

Which substances are made

up of only one type of atom?

129


Homework 1

Year 9 Science

1. Which of the boxes below contain ‘elements’? Explain your answer.

Extension Homework

Look at the diagram below. Which one of the substances is an element? Is

this substance a solid, a liquid or a gas?

Did you know…

Another way to describe what elements are is to say that they are

substances that cannot be broken down into anything simpler – if you break a

piece of a solid element into two pieces, you just have two pieces of that

element!

130


Year 9 Science

In the last pages you learned that the names of all the elements can be found in

the ‘Periodic Table’.

You will not need to know all of them (there are over 100!) but you should try to

remember some of the more important ones and maybe even their symbols.

Match the name of the element with the piece of information about it…

This element rusts…

This element has the symbol H…

This element has the symbol S…

This element turns blue in the presence of starch…

This element makes up about 21% of air…

This element has the symbol Cu…

This element makes up about 78% of air…

This element is used to make jewellery…

This element is used in swimming pools…

Chlorine

Iodine

Nitrogen

Silver

Hydrogen

Iron

Oxygen

Sulphur

Copper

All these element names can be found in the Periodic Table.

Sulphur

Sodium

Silver

Carbon

Zinc

Dimitri Mendeleev

helped put together

much of the Periodic

Table we use today.

131


Year 9 Science

All elements in the Periodic Table have symbols.

Sometimes the symbol is simply the first letter of the element’s name –

Oxygen’s symbol is O.

Sometimes the symbol is the first two letters of the name – Helium’s symbol is

He.

Sometimes the symbol is even the first and third letters of the name like for

Magnesium Mg.

Sometime the symbol seems really random like the symbol for Sodium which is

Na.

Use the Periodic Table above (or a bigger one in your school diary) to find the

symbols for the following elements…

1. Copper

2. Carbon

3. Hydrogen

4. Helium

5. Calcium

6. Iron

7. Potassium

8. Cobalt

Why did the boy tell the girl

that he thought she must be

made of Copper and

Tellurium?

Because he thought that she

was CuTe.

132


Year 9 Science

Homework 2

1. Copy and complete the table…

Symbol of element

Ca

Mg

Cl

Pb

Name of element

Nitrogen

Silver

2. The table below shows the percentages of the different elements that

are found in the earth’s crust (outer layer that we are standing on)…

Element

Percentage

Oxygen 48

Silicon 26

Aluminium 8

Iron 5

Calcium 4

Sodium 3

Potassium 2

Magnesium 2

Other elements 2

Draw a bar chart to show this information.

Numeracy in Science

Extension Homework

Numeracy in Science – Very Difficult

Draw a pie chart to show the information in the table in Question 2 above.

Did you know…

That the symbols for elements are international – they are the same all over the

world no matter what language is spoken.

133


Year 9 Science

Before you move on try to solve the code.

The sentence below is made up of element names.

If you change the names to their symbols it will reveal a message.

A few letters have been de-coded for you already to get you started.

NitrogenOxygenTungsten

YittriumOxygenUranium

PotassiumNitrogenOxygenTungsten

CarbonHeliumMIodineCarbonAluminium

SulphurYittriumMBoronOxygenLSulphur

Did you crack the code?

Now for a final look at some elements…

The black line in the Periodic Table separates the metal elements (on the

left of the line) from the non-metal elements (on the right).

It may be surprising to see that there are so many elements which are

metals.

You can have a look at some metals and non-metals…

134


Year 9 Science

Copy out the table below in your exercise book. Then have a look at the metals

and non-metals which the teacher will give you and with a partner try to fill in

the table …

Property Metal Non-metal

Appearance

Strength

Hardness

Density

Melting point

Does it conduct heat?

Does it conduct

electricity?

The uses of an element depend on its properties…

For example why do you think aluminium is used to make aeroplanes? Why is

copper used to make cooking pots and electrical wires? Why is Gold used to

make jewellery?

Homework 3

1. Write down the names and symbols of 5 metals and 5 non-metals.

2. Caitriona has found a lump of black solid. It is light, breaks easily and

does not conduct electricity. Is it a metal or a non-metal?

3. Some objects could be made of metal or of plastic. Give the

advantages and disadvantages of metal and plastic for making each of

these objects…

a. Ruler

b. Window frame

c. Spoon

d. bucket

Extension Homework

Name 4 objects in your house which are made of metal elements. Which

metals are they made from and why do you think they are made from these

metals?

135


Year 9 Science

Now you need to learn about substances in which the atoms are not all the same

type…

For example…

In all three of these diagrams the substances are made up of from more than

one type of atom.

So these substances are not elements.

The names of these substances will not be in the Periodic Table of elements.

These substances are not pure.

There are two different types of ‘impure’ substance – mixtures and compounds.

This is a mixture of two different elements.

You can see that there are two different types of

atoms in this substance so it is not a single element.

None of the different atoms are joined together – they

are only mixed together so this type of substance is

called a mixture.

Now look at this substance…

In this substance there are also two

different types of atom present.

This time there are some atoms which are

joined together.

These groups of atoms are called

‘molecules’

None of the molecules contain different

types of atoms so this is still just a

mixture.

136


Year 9 Science

What about this substance?

In this substance there are different types of atom

so it is clearly not an element.

This time different types of atoms are not only

present but they are joined together chemically.

This type of substance is called a ‘compound’.

Look at the substance on the right…

There are different types of atoms and the

different types are joined together.

This is a compound.

This time the atoms are in rows and columns so this is

a solid compound.

So to summarise…

An element is a pure substance in which all the atoms are of the same type.

A mixture contains different types of atoms but the different atoms are not

joined together.

A compound is made from different types of atoms which are chemically

joined together.

Activity

1. Copy out the diagrams on the right.

Write underneath each if the

substance is an element, a mixture

or a compound.

Explain each of your answers.

137


Year 9 Science

Homework 4

Draw the diagrams and answer

the questions

1. Which box(es) contains

a. An element

b. A mixture of 2 elements

c. A compound

d. A mixture of 2 compounds

e. A mixture of an element

and a compound

Extension Homework

Draw the diagrams and answer the

questions…

Which box(es) contain…

a. An element

b. A compound

c. A mixture of an element and 2

different compounds

In your homework you might have seen some difficult questions.

Let’s have a look at some more complicated substances…

+ =

This first substance is

made up of atoms which

are all the same type so

it is an element’ (pure)

This next substance is made up

of different types of atoms

which are joined together – so

it is a ‘compound’

This substance is made up of the element

and the compound mixed together (but

not joined with each other) so it is a

mixture of an element and a compound.

138


Year 9 Science

The diagram below summarises the work so far in this topic…

These diagrams summarise what you have

learned so far- atoms are represented by

coloured circles (different colours mean

different types of atom) .

Two (or more) atoms joined together is

called a ‘molecule’.

Homework 5

Draw particle diagrams to show the following types of substance…

a. A solid element

b. An element made up of molecules

c. A compound

d. A mixture of 2 elements

e. A mixture of an element and a compound

Extension Homework

Draw particle diagrams to show the following types of substance…

a. A mixture of two compounds

b. A mixture of an element and two compounds

139


Year 9 Science

Next you are going to look briefly at the names and formulae of some

compounds…

You know that the symbol for Oxygen is O.

The symbol for Carbon is C.

Imagine if lots of Carbon atoms joined with lots of Oxygen atoms to make a

compound – let’s say one Carbon atom joins with each Oxygen atom in this

compound.

It might look like this…

if the black circle represents the

Carbon atom and the red circles represent the Oxygen atoms.

Of course there wouldn’t just be one molecule of the compound; there would be

lots of them…

Each molecule in this substance is made up of two

different types of atom joined together so the

substance is a compound.

One Carbon atom (C) is joined with one Oxygen (O) atom

in each molecule so the ‘formula’ for each molecule is

CO.

The name of this compound is Carbon Monoxide.

Now what if the Carbon and Oxygen reacted with each slightly differently and

each Carbon atom joined with two Oxygen atoms…

Each molecule of this compound would look like this…

This compound is different than the one

above (even though it contains the same

types of atoms) because each molecule is

different than the molecules of the

compound above.

This time each Carbon atom is joined with

two Oxygen atoms to make each molecule

so the ‘formula’ is CO 2

140


Year 9 Science

Activity

Use the key for the different types of atom to find the formulae for the

compound molecules below…

= Oxygen atom = Carbon atom = Nitrogen atom

= Hydrogen atom = Chorine atom = Sodium atom

a.

a.

a

b. c.

d. e. f.

When atoms of different elements join together like this, it is called a ‘chemical

reaction’. You will learn more about these in Year 10.

Homework 6

1. Draw the molecules of the following compounds using the formulae given.

(Don’t forget to do a key to show which atom each circle represents)

a. CaCl 2 e. SO 2

b. CuO f. NH 3

c. MgO g. NaOH

d. CH 4

Extension Homework

Draw the molecules of the following compounds using the formulae given.

a. H 2 SO 4 b. NaCO 3

141


Year 9 Science

Now you are going to find out more about mixtures and in particular how we can

quite easily separate mixtures.

Remember that a mixture is made up of different types of atoms mixed

together but not joined chemically. This means that we have simple ways by

which we can separate these atoms again.

However, there are different methods and we have to decide which method to

use depending on the mixture we want to separate.

Imagine you want to separate potatoes from water in your house.

How could you do this?

You might use a piece of

equipment like this…

It is called a colander.

Can you explain how it works?

So basically the holes allow the water through but stop the potatoes going

through.

What if we now wanted to separate rice from water? Would the colander still

work? The holes in the colander might be big enough to allow some grains of rice

through so it wouldn’t work too well. We would need something with even smaller

holes – a sieve!

Now the holes in a sieve are so

small that you can just about see

them.

They allow the water through but

stop the rice grains going through

so they separate the rice from

the water!

142


Year 9 Science

But what if we had something with even smaller particles mixed with water – say

sand. How would we separate the sand from the water? The holes in a sieve are

still too big because they would allow some grains of sand to go through. We

need a piece of equipment with even smaller holes!!!

These pictures show pieces of filter paper. The image on the right shows filter

paper magnified under a microscope so you can see he holes (the black areas

where water can get through but grains of sand would get ‘caught’)

You can now use filter paper to separate sand from water.

Method…

1. Gather all equipment.

Filter paper Filter Funnel Conical Flask Sandy water

2. Fold the filter paper as shown below and place in the funnel and in the

flask.

3. Then pour the sandy water into the funnel and wait!

143


Year 9 Science

You should have successfully separated sand from water using thee method

called ‘filtering’ or ‘filtration’.

This method only works to separate solids which are insoluble (do not dissolve)

from water. This is because if the solid particles are small enough to dissolve

they would also be small enough to pass through the holes in the filter paper.

Filtering can separate insoluble solids from water.

You should also notice that this separation was to separate a mixture of two

compounds (sand and water).

Homework 7

Write up the experiment on ‘Filtering’ sandy water to include an equipment

list, method, risk assessment and conclusion.

Extension Homework

Write an evaluation for your experiment write-up.

Next you need to learn a method to separate a mixture of a ‘soluble’ solid from

water. The mixture you will use is salty water and the method is ‘Evaporation’…

Method…

1. Gather the equipment

Evaporating dish Gauze Tripod Heat proof mat Bunsen Burner

2. Set dish on top of gauze on top of tripod

on heat-proof mat as in diagram.

3. Place Bunsen Burner under dish and light.

4. Use hot flame to heat salty water mixture.

144


Year 9 Science

You should have now successfully separated salt from a salty water mixture.

Homework 8

Write up the experiment on ‘Evaporation’ of salty water to include an equipment

list, method, risk assessment and conclusion.

Extension Homework

Write an evaluation for your experiment write-up.

You will have noticed when finishing the last experiment on separating salt from

salty water that you ‘lost’ the water as it evaporated into the air.

What if you wanted to get pure water from the salty water mixture?

The ‘evaporation’ method would not achieve this.

Now you need to learn about another method of separating which will achieve

this…

It is called ‘Distillation’ and is basically very similar to evaporation but this time

you ‘catch’ the water as it evaporates into steam and you cool the steam quickly

so it turns back into liquid water.

Method…

The salty water is placed

in a round bottomed

flask and heated over a

Bunsen Burner.

The steam is passed

through a condenser

which has cold tap water

circulating round it.

This cools the steam and

turns it back into pure

water which drips out

into the beaker.

145


Year 9 Science

Activity…

Write a paragraph to explain the experiment on ‘distillation’ and how it

separates pure water from salty water.

Extension Activity…

Imagine if a mixture is made up of more than 2 different liquids mixed.

Imagine there are 5 or 6 different liquids mixed together.

We use a method very similar to ‘distillation’ to separate out all the different

liquids.

It is called ‘fractional distillation’ and the different liquids we separate out are

called the ‘fractions’.

An example of a mixture of

liquids is ‘crude oil’ which is

actually a mixture of many

different liquids.

To separate them we simply put

them in a furnace and heat them

until they all evaporate.

We then let them all begin to

cool down until each condenses

back into a liquid at different

temperatures.

We collect each one at a

different part of the

fractionation column.

Homework 9

Numeracy in Science

A sample of crude oil was found to have the following contents…

Substance Amount in crude oil

Gasoline 30%

Kerosine 10%

Diesel Oil 40%

Fuel Oil 20%

Draw a bar chart to show this

information.

146


Year 9 Science

Now you have learned about the first three methods of separating mixtures,

you can use these to solve this problem.

Erin was given a beaker of sand a beaker of salt but somehow she mixed the two

powders together. She now wants to separate them again.

How can she do this?

The first step is actually to add

something! Water!

Then stir until the salt dissolves.

Now you can filter the sand and the

salt will pass through the filter

paper along with the water.

You now have the sand!

Next you take the salty water and heat it

over a Bunsen Burner.

The water will evaporate and you will be left

with the salt.

Now you have the salt!

By using these 2 methods in combination you

have separated the sand from the salt

Homework 10

The 7 sentences are about separating pure salt from rock salt (a mixture of sand and

salt). Write them in the right order so they make sense.

The mixture is filtered

The solution is evaporated gently to leave dry salt

The salt dissolves

The mixture is warmed and stirred

The salt solution passes through the filter paper

Water is added to the mixture

The sand is collected in the filter paper

147


Year 9 Science

Next you are going to learn about a method to separate different coloured dyes

from ink.

This method is called ‘Chromatography’

Method…

1. Gather equipment – chromatography paper, water, beaker, coloured

markers.

2. Place a dot of ink on the bottom of the chromatography paper.

3. Wrap the other end of the paper around a wooden splint so that it just

dips into the water in the beaker when the splint is balanced on the rim

of the beaker.

4. Wait until the ink separates out as it rises up the paper.


Colour of marker

Colours observed on paper

Homework 11

Look at the chromatography paper from an experiment.

a. Which two inks contain only one dye?

b. Which ink contains three dyes?

c. Which colour would spot x be?

d. Explain your answer o part (c)

x

green yellow red brown

148


Year 9 Science

Your final method of separating a mixture is very simple.

It is used when separating a magnetic material from a non-magnetic material. –

such as iron and sulphur…

Method…

1. Add the sulphur powder and the iron powder together and stir with a

glass rod.

2. Use the glass rod to spread the mixture thinly over the surface of a

piece of paper.

3. Pass the magnet over the mixture several times until the iron is

separated from the sulphur powder.

Activity…

The method you used to separate sulphur and iron is ‘using a magnet’. This only

works if one of the substances in the mixture is magnetic and the other is not.

Which of the following mixtures could be separated in this way?

(Hint: Use the internet to help you find out which materials are magnetic)

a. Steel filings and iron filings

b. Steel cans and aluminium cans

c. Sand and salt

d. Copper pieces and iron pieces

e. Nickel shavings and gold shavings

149


Year 9 Science

Homework 12

From the different methods of separation you have now learned, choose which

one would be most useful to separate each of the following mixtures.

a. Coffee granules from water

b. Mud from water

c. Steel paper clips from aluminium paper clips

d. Pure water from salty water

e. Different colours of dye from paint

Extension Homework

An alloy is a mixture of metals. Carry out research to

find out what are the contents of the following alloys…

a. Steel

b. Stainless steel

c. Brass

d. Ferrochrome

Scan the QR code to

watch the short video

on magnetic separation.

Before you finish this topic have a look at some careers in this area of science…

Careers in Science

A forensic scientist collects and analyses

evidence from crime scenes.

Sometimes they have to use methods like

chromatography to separate solutions to

find out where they came from.

To become a forensic scientist you would

need at least 4 GCSEs including science

and at least one A-level in a science

subject.

The starting salary is normally about

£20,000 per year but it can rise to about

£45,000 per year for senior forensic

scientists.

150


Year 9 Science

Careers in Science

A chromatographer is a scientist who specialises in separating compounds. They

may develop new products for beauty or health new medicines or even brand new

substances. A chromatographer usually needs to study science to A-level and

then at university and salaries start at around £27,000 per year.

Literacy in Science

Here are some of the key words from this topic along with their meanings…

Element – a substance which is made up of only one type of atom

Mixture – a substance in which 2 or more substances are mixed together

Compound – a substance made up of different atoms which are joined together

chemically

Atom – a particle which everything is made up of

Molecule – a particle made up of two or more atoms joined together

Filtration – a method of separating an insoluble solid from a liquid

Evaporation – a method of separating a soluble solid from a liquid

Distillation – a method of separating a liquid from a solid dissolved in it.

Chromatography – a method of separating different coloured dyes from ink

151


Year 9 Science

You have now finished this topic and, in fact, you have finished all your Year 9

topics.

Now you need to get ready for your Summer Science exam.

To help you do this, use the mind-maps below…

Food Tests

Why and how

we breathe

The parts of

the breathing

system and

their jobs

Testing the

grip on shoes

Force words –

push, pull etc

How we show

forces using

arrows

Process of

digestion

Topic 1

‘Staying

Alive’

What is in

air?

How we can

reduce

friction

Topic 2

‘Forces’

How we

measure

forces –

force-meters

Teeth –

different

types and

structure

The parts of

the digestive

system

The main

nutrients in

our food

Balanced and

Unbalanced

forces

Friction

Floating and

sinking and

Upthrust

What is

diffusion?

Solids, liquids

and gases –

particle

arrangements

Solids, liquids

and gases -

properties

Static

Electricity

Bar magnets

and what sticks

to them

Rules for

attraction

and repulsion

How dissolving

can be speeded

up

Topic 3

‘Matter’

How solids,

liquids and

gases expand

h h t d

Series and

parallel

circuits

Topic 4

‘Magnetism

and

Electricity’

Magnetic

field pattern

What is

Dissolving?

Air

Changes of

state

Symbols for

circuit

components

Simple

circuits

Electromagnets

Designing

keys

Keys and how

to use them

Microbes

What is meant

by ‘habitat’ and

‘environment’

Topic 5

‘The

Environment’

Food Webs

Adaptation

Migration

and

Hibernation

Food Chains

Fractional

Distillation

Separating

techniques

Atoms

Topic 6

‘Elements,

Compounds

and

Separations’

Particle diagrams

Elements

Mixtures

Compounds

152


Extra Activities for Topic 1: Staying Alive

Year 9 Science

You can do these activities if your teacher is not in class or if you just want to

do some extra work to improve your science knowledge…

a. Being Creative – Design and produce a poster of the breathing

system, fully labelled.

b. Literacy in Science / Being Creative - Use squared paper to help

you design a cross word about the topic ‘Staying Alive’. First mark

out the space on the squared paper you will use, then write in some

answers using pencil, next make up some clues for these answers and

write them underneath, next shade in any unused squares and finally

rub out the answers you had put in.

c. Being Creative – Design and produce a poster of the digestive

system, fully labelled.

d. Research – Carry out research to find out how much of each type of

nutrient we need in our diets and produce a bar chart to show this

information.

Extra Activities for Topic 2: Forces



a. Being Creative – Draw a poster to show different situations

where forces are being applied (for example – a girl falling with a

parachute, a man pushing a wheelbarrow etc). On each diagram

draw arrows to show all the forces in action.

b. ICT Research – Use a computer to research the famous

scientist ‘Isaac Newton’ and write a report about his life and

work.

c. Literacy in Science – Write a sentence to explain each of the

following… a ball falls to the ground when you let it go, a piece

of wood floats on water, a huge boat floats on water, an iron nail

sinks in water, two teams in a tug-o-war pull and the rope stays

still.

153


Year 9 Science

Extra Activities for Topic 3: Matter



a. Literacy in Science / Being Creative - Use squared paper to help you

design a cross word about the topic ‘Matter’. First mark out the space on

the squared paper you will use, then write in some answers using pencil,

next make up some clues for these answers and write them underneath,

next shade in any unused squares and finally rub out the answers you had

put in.

b. ICT Research – Use a computer to research the famous scientist ‘Albert

Einstein’ and write a report about his life and work.

c. Being creative - Design a poster to show the particles in

(i) A solid

(ii) A liquid

(iii) A gas

d. Literacy in Science / Being Creative - Use squared paper to help you

design a word-search about the topic ‘Matter’. First mark out the space on

the squared paper you will use, then write in the words you want to include,

next write these words underneath the square and finally fill in all the

unused squares with random letters.

e. Research – Carry out research to find out about the following types of

substance…

(i) Gel

(ii) Plasma

(iii) Emulsion

(iv) Foam

154


Year 9 Science

Extra Activities for Topic 4: Electricity and Magnetism



a. ICT Research / Careers – Use a computer to research ‘electrical

engineer’ and write a report about what they do.

b. Numeracy / Managing Information - Use the data below to plot a scatter

graph of Voltage across electromagnet against the number of paper=clips

it can lift.

Voltage across

electromagnet (V)

1 2

2 5

3 8

4 12

5 16

6 20

7 23

Number of paper-clips

lifted

c. ICT Research / Literacy – Use a computer to research the life and work

of Michael Faraday. Write a report about what you found out.

d. ICT Research – Use a computer to research the different ways of

making electricity eg. battery, photocell, wind turbine, hydroelectricity,

burning fossil fuels. In your report mention the advantages and

disadvantages of each one and how each affects the environment.

e. ICT Research / Literacy – Use a computer to research the life and work

of Benjamin Franklin. Write a report about what you found out.

f. Numeracy / Managing Information - Use the data below to plot a bar

graph of Number of coils of wire against the number of paper-clips it can

lift.

Number of coils of wire

in the electromagnet

20 2

40 14

60 28

80 56

Number of paperclips

lifted

155


Year 9 Science

Extra Activities for Topic 5: The Environment



a. Being Creative – Use one of the food-chains or Food-webs you have

already done in this topic to produce a fully coloured poster of a Foodchain/Food-web.

Label all parts of the diagram.

b. Being Creative – Design and draw a poster to explain how to use the

various pieces of field study equipment you have learned about.

c. Being Creative – Design a leaflet to tell people about the importance and

advantages of ‘Recycling’


design a word-search about the topic ‘The Environment’. First mark out

the space on the squared paper you will use, then write in the words you

want to include, next write these words underneath the square and finally

fill in all the unused squares with random letters.

e. ICT Research / Careers – Use a computer to research the ‘Lough’s

Agency’ and the work they do. Write a summary of the work they do.

f. Being Creative – Design a brochure to tell people about how they can

protect the environment – litter, recycling, using bags for life etc.

g. ICT Research – Use a computer to research Charles Darwin and write a

report about his life and work.

h. Watch - Watch an episode of David Attenborough’s Frozen Planet. The

teacher will provide this.

i. Being Creative - Design an animal which could live on an alien planet –

describe the conditions on the planets and the features of the animal

that make it well adapted to surviving on the planet.

156


Year 9 Science

Extra Activities for Topic 6: Elements, Compounds and Separations



a. ICT Research / Careers – Carry out your own research into a job which

uses the type of science in this topic.

b. Being creative - Design a poster to show the particles in

(i) An element

(ii) A mixture

(iii) A compound

c. Revision – Spend your time revising for your Summer exam in science.


design a word-search about the topic ‘Elements, Compounds and

Separations’. First mark out the space on the squared paper you will use,

then write in the words you want to include, next write these words

underneath the square and finally fill in all the unused squares with

random letters.

157


Year 9 Science

Topic 7: Numeracy in Science

Lastly you need to spend a little time practicing some maths skills which are

useful in science.

This year you are going to focus on equations and how we sometimes need to

rearrange them.

Let’s start by looking at an example…

Speed = Distance ÷ Time

If you are given the Distance and Time then it is easy to know what to do with

them – Divide Distance by Time because the equation tells you exactly what to

do.

Eg. A woman runs 16 kilometres in 2 hours. What is her speed?

Speed = Distance ÷ Time

Speed = 16 ÷ 2 = 8 km/h

But what if you are already told the speed and also the distance and you are

asked to find the time – what do you do then?

Answer – Rearrange the equation to make the thing you need to find out the

‘subject’ of the equation…

To do this you can simply move things from one side of the equation to the

other side – the only thing you need to remember is to reverse the operation.

In other words – if a divider sign is in front of Time on one side, when you move

Time to the other side of the equation you put a multiplication sign in front of it

instead.

So the equation becomes…

Speed x Time = Distance

158


Year 9 Science

Now try these questions using this new skill.

1. A car is travelling at a speed of 20 m/s. If it travels for 60 seconds,

how far will it have gone?

2. A man on a bicycle cycles for 2 hours at an average speed of 15 km/h.

How far does he go?

3. An aeroplane goes from Dublin to New York which is a distance of

2000 Km. It takes 8 hours. What is the average speed of the plane?

This method for rearranging equations works for lots of different equations…

For example there is an equation which states that…

Force = Mass x Acceleration

We can rearrange this equation to make acceleration the subject instead – this

means rearranging the equation to have acceleration on its own on one side and

moving the other two things to the other side. We just follow the rule from the

previous page

Acceleration = Force ÷ Mass

So if you are given the force and mass you can rearrange the equation to find

the acceleration.

Now try to rearrange these equations…

1. Rearrange Voltage = Current x Resistance to make Resistance the

subject of the equation.

2. Rearrange Force = Mass x Acceleration to make Mass the subject

of the equation.

3. Rearrange Power = Voltage x Current to make Voltage the subject

of the equation.

159


Year 9 Science

Now try to rearrange the equations to solve the problems below…

1. The current in an electric circuit is 5 Amps. The Voltage supplied by

the battery is 6 Volts. What is the resistance in the circuit.

The equation you need to use is Voltage = Current x Resistance

2. A train travels at an average speed of 100 Km/h and travels from

Derry to Belfast – a distance of 150 Km. How long does it take?

The equation you need to use is Distance = Speed x Time

3. A car starts on a journey and speeds up from 0 m/s to 30 m/s. This is

a change of speed of 30 m/s. The car takes 5 seconds to do this

change of speed. What is the acceleration of the car?

The equation you need to use is

Acceleration = change of speed ÷ Time

160


I read a book about gravity. I couldn’t put it

down.

We sent men to the moon with a computer

that was less powerful than your mobile

phone!

Year 9 Science

Millions of

people saw the

apple fall.

Isaac Newton

asked ‘Why?’

When I

found out

that Oxygen

and

Magnesium

were dating I

was like…

OMg

It’s not that I am smarter than other people.

I just keep trying for longer.

I never trip and fall – I just do random

gravity checks!

‘This is one small step for a man but one giant

leap for mankind’.

‘If I have

seen

further, it is

by standing

on the

shoulders of

giants’.

Isaac

Newton

Neil Armstrong

Do I know any

jokes about

Sodium and

Hydrogen?

NaH !

Impossible is

not a scientific

word.

Mistakes are just proof

that you are trying.

When life gives you lemons, make a simple battery.

Science is simply common sense at its very

best!

161

Year 9 Textbook

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template ?