2018_SCIENCE Teacher

Unit 5 - More about Plants

Exercise 10

Read carefully and understand each statement below. Write TRUE or FALSE for each
statement.
1. Soil erosion is NOT a serious environmental problem. ____________________
2. Plants need water to make its food. ____________________
3. The stem holds the plant firmly in the soil. ____________________
4. Plants DO NOT need minerals to grow properly. ____________________

Exercise 11

1. Name two plants which are grown around sugarcane fields to control soil erosion
(an example is already given).

a. "petit bambou" b.___________________ c.__________________

2. Observe the picture. It shows an area of land
after heavy rainfall.
(i) Is the land covered with trees? _____________

(ii) What has happened to the soil after the heavy rainfall?
__________________________________________________________________________
(iii) Explain why this has happened.
__________________________________________________________________________
(iv) Explain how the roots of plants can prevent soil erosion.
__________________________________________________________________________

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Unit 5 - More about Plants

Exercise 12

Picture A Picture B

Compare pictures A and B which show part of filao trees on a beach.
1. Describe what you see in pictures A and B.

Picture A:__________________________________________________________________

__________________________________________________________________________

Picture B:_________________________________________________________________

__________________________________________________________________________

2. What process is responsible for what you see in picture B?
__________________________________________________________________________________

3. How can the process mentioned in (2) above be prevented?
__________________________________________________________________________________
__________________________________________________________________________________

Exercise 13

Fill in the blanks in sentences (1) to (4), using the correct word from the given list.

erosion over-grazing wash sloping vegetation

1. Soil ________________ takes place when the top fertile soil is removed.

2. When cattle eats up a lot of grass from the soil there is __________________.

3. Terracing is done on ___________________ sides of hills.

4. Dense ______________helps prevent heavy rains to _____________away the top soil.

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Unit 5 - More about Plants

I check my progress

At the end of this unit, I can

• identify and name the different parts of a plant.
• demonstrate understanding that different parts of a plant have

different functions.
• state the functions of the fruit, flower, seed, root and stem of
a plant.
• carry out an experiment to show that the roots absorb water

from the soil.
• show that the stem carries water to other parts of the plant by

an experiment.
• observe plants in my environment and learn about them.
• define soil erosion.
• state the causes and effects of soil erosion.
• list measures to prevent soil erosion.
• explain that leaves make food for the plant during the day.
• list what is needed by the plant to make its own food.

43

Unit 5 - More about Plants

Teacher’s note pg 45

UNIT 6: Energy

Learning outcomes

At the end of this unit, pupils should be able to:
• Recall that we need energy to do many activities
• Explain the meaning of energy
• Define a source of energy
• Identify and name common sources of energy
• Give examples of fossil fuels and state their uses
• Identify and name different forms of energy
• Understand the difference between source and form of energy

This unit aims at enabling pupils to explore other sources and forms of energy, from what they have
already studied up to standard IV level. This will be achieved through observation of various contexts
given in terms of pictures. Pupils are encouraged to have group discussions under the guidance of
teachers. Pupils are also encouraged to express themselves after the discussions on topics related
to energy in our everyday life. They may express their ideas orally, by writing, by drawing or even by
role playing. Teachers should encourage pupils to find out additional information related to energy
from the Internet, from books, from parents, from encyclopaedia and other curriculum materials
like posters.

In this unit, pupils will also recall what they have learnt in standard IV and in earlier classes. In fact,
they already hold prior knowledge about the sun, wind and petrol as sources of energy. They are
also aware of forms of energy such as light, heat and movement. Teachers will consolidate these
ideas and build on them to teach about additional sources such as fossil fuels and additional forms
of energy such as chemical energy.

Teachers should encourage pupils to perform certain safe activities at home under the guidance
of their parents. This would ensure follow-up of the concepts learnt at school and enable pupils to
develop a holistic understanding of energy. Doing follow-up activities at home is very important
as the home environment is very different from the school environment and we can come across
very different examples that would enrich learners’ experiences.

44

Energy Unit 5 - More about Plants

UNIT 6

In Grade IV, you learnt
that energy is needed to
do various activities. You
identified and named some
sources and forms of energy.
You stated some common
uses of energy.

Energy enables us to move
and work. We need it to
operate simple devices
around us. What would
happen if we do not have
energy?

In this unit, you will further understand the meaning of energy and why we need it. You will learn
about sources of energy, including fossil fuels. You will find out the many forms of energy such
as light, heat, movement, chemical, sound and electrical energy.

At the end of this unit, you should be able to:

• recall that we need energy to do many activities.
• explain the meaning of energy.
• define a source of energy.
• identify and name common sources of energy.
• give examples of fossil fuels and state their uses.
• identify and name different forms of energy.
• understand the difference between a source and a form of energy.

45

Unit 6 - Energy

Teacher’s note pg 47

Activity 6.1: Living things need energy
Learning outcomes:
By the end of the activity, pupils should be able to:
• State that energy is needed by animals and humans to do their activities
• State that the energy needed for our activities is obtained from food
• Recall that plants get energy from the sun
Skills: observe pictures, relate to the activities depicted, communicate their ideas in oral and
written forms, literacy
In this activity the focus is on what is energy, where do we get energy from and what happens if
we do not have energy.
Pupils observe human beings and animals such as fish. The fish are moving and the people are
doing their activities.
Through discussion in groups, pupils are made to state that for all the activities, energy is needed.
This energy is obtained from the food that humans and animals eat. If we do not have energy, we
will not stay alive.
Pupils learn that plants produce their own food. Energy from the sun is needed for plants to make
their food.
Pupils learn that living things such as humans, animals and plants need energy for their activities.
In the next activity, pupils will learn that even non-living things need energy to function.

46

Unit 6 - Energy

9 10
8

7 Activity 6.1 Living things need energy
6
5
4
3
2
1
0

I remember Think What is energy?
and think Where do we get energy form?
What will happen if we do not have energy?

cyclist mason

fish swimming

Study the pictures and answer the questions:

1. What is needed by the cyclist and the fish to move? pupil writing
_____________________________________

2. What is needed by the pupil and the mason to work?
_______________________________________________________________________

3. From where do they get the energy they need? _____________________________________

The energy obtained from food helps us to do many activities. For example, we use energy to
walk, move, work and play. We also need energy when we sleep. Energy helps us to stay alive.

4. Name THREE other activities where we use energy.

a._________________________ b. ____________________ c. _____________________

I conclude from my observations

All living things need energy to live, grow and do various daily activities. Humans
and animals get energy from different types of food.
In Unit 5, you learnt that energy is needed by plants to make their food.
From where do plants get energy?____________________________________

47

Unit 6 - Energy

Teacher’s note pg 49-51

Activity 6.2: Some non-living things need energy

Learning outcomes:
By the end of the activity, pupils should be able to:
• State that energy is needed by non-living things to perform their functions
• State examples of non-living things at home and at school that need energy to operate
• Demonstrate understanding that machines need energy to operate
• List places where machines are used

Skills: observe pictures, relate to the machine depicted, communicate their ideas in oral, tabular
and written forms, literacy

In this activity pupils study examples of non-living things such as torch and car that need energy to
operate. They list two items at home and two at school that need energy to operate.
Pupils also recognise that a machine needs energy to operate in an agricultural field. They need
to list three more places where machines are used. Through discussions, they will state examples
such as garment factories for cutting clothes, for stitching, car manufacturing industries and
photocopying machines.

After discussing about energy needed by living as well as non-living things, pupils conclude that
energy is needed to move and do work.
The discussion is now focussed on sources of energy needed by humans, animals and non-living
things. Pupils are taught that the energy needed by humans and animals is obtained from food
that is eaten whereas plants obtain energy from the sun.
Additional sources of energy that have been learnt earlier by pupils are petrol, batteries and wind.

The next part of the activity requires pupils to identify sources of energy in various contexts.
Through group discussions pupils will identify the sources of energy in the examples given and then
record the answers in the table provided. One example is given to facilitate the discussion.

For the sailing boats, the energy is provided by the wind. So the source of energy is wind. For the
person cutting sugar cane, the source of energy is the food that he eats. For the clothes drying in
sunlight, heat is needed and the source of energy is the sun.

For the puppies running on the ground, the source of energy is the food eaten by them. As for
the bus, it runs using petrol, so the source of energy is petrol. Similarly, for the drying octopus heat
energy is needed so the source of energy is the sun.

After discussion on the above six examples, a source of energy is defined as the item from which
the energy is obtained. Now pupils will study about fossil fuel as source of energy.

48

Unit 6 - Energy

9 10
8

7 Activity 6.2 Some non-living things need energy
6
5
4
3
2
1
0

Some non-living things need energy to operate. Cars need energy to move.
A mobile phone needs energy to work. A bulb needs energy to light.

Answer the questions below:

1. Name TWO other non-living things at home that need energy. To operate something
a. _____________________ b. _____________________ means to make it work.

2. Write TWO sentences to say why each one needs energy.

a. ________________________________________________________________________

b. ________________________________________________________________________

3. Name TWO non-living things at school that need energy.

a. _____________________ b. _____________________

4. Write TWO sentences to say why each one needs energy.

a. ________________________________________________________________________

b. ________________________________________________________________________

5. Most machines need energy to work. The picture below shows a machine working in a field.

Name THREE other places where we use machines.
a.______________________________

b.______________________________

c. ______________________________

a machine 49

Unit 6 - Energy

What is energy?

Energy is what make things move and to work.

What is a source of energy?

People, animals and plants get energy in many ways.
People and animals get energy from food that they eat.
Plants get energy from the Sun.
A source of energy is where the energy comes from.
There are different sources of energy around us. Food and the Sun are important sources of
energy.
Name TWO other sources of energy that you learnt in Standard IV.
1. _______________________________ 2.___________________________________
The pictures below show various activities. For each activity shown, state where the
energy comes from. Using the example given, complete Table 6.1.

50

Unit 6 - Energy

Table 6.1 Where does the energy come from? (Source of energy)
How energy is used? Energy comes from the wind.
To sail boats

What I have learnt

Energy is needed to make things move and to work.

All living things need energy. Living things use energy to carry out certain activities.

Energy is useful to us in many ways. We need energy to grow, move, work, study and
play. We also use energy to sail boats, to fly kites and planes, to dry clothes and do other
activities.

Some non-living things like a car or torch need energy to operate.

Energy comes from different sources.

A source of energy is where the energy comes from.

Different sources of energy are available.

The sun, food, wind and petrol are sources of energy.

Keywords to learn

move work energy activities operate machine source

51

Unit 6 - Energy

Teacher’s note pg 53

Activity 6.3: Fossil fuels are sources of energy
Learning outcomes:
By the end of the activity, pupils should be able to:
• Identify and name fossil fuels as sources of energy
• State examples of fossil fuels
• Explain the origin of fossil fuels
Skills: observe pictures, relate to the items depicted, communicate their ideas in oral and written
forms, literacy
Pupils have already learnt about petrol as a source of energy. They now learn that petrol forms
part of a group of fuels called fossil fuels.
The examples given to discuss are:
1. A stove operating using natural gas or cooking gas
The source of energy is natural gas. It comes from the Earth.
2. Coal
Coal is black in colour. It comes from the Earth.
So coal, petrol and natural gas are fossil fuels obtained from the Earth. The fossil fuels are burnt to
obtain energy. Fossil fuels are found deep underground. They were formed millions of years ago
from dead animals and plants.
In Mauritius, we use coal to produce electricity.

52

Unit 6 - Energy

9 10
8

7 Activity 6.3 Fossil fuels are sources of energy
6
5
4
3
2
1
0

Let us learn about other sources of energy. Fossil fuels are important sources of energy.
Fossil fuels were formed millions of years ago from dead plants and animals. You learnt
about petrol in Standard IV. Petrol is a fossil fuel. Let us find out more types of fossil fuels.

Picture A is a stove. What source of energy is being used?
________________________________________

Where does natural gas come from?
________________________________________

Natural gas is also called cooking gas.

Picture A

Picture B shows coal. Coal is another type of fossil fuel.
What is the colour of coal?___________________
Where does coal come from?___________________

Picture B

Natural gas, coal and petrol are fossil fuels. They are common sources of energy that
people use daily.

We get energy by burning fossil fuels.

Find Find out and learn more about fossil fuels from the Internet.
out

Did you know?

Coal is used to produce electricity in Mauritius.

53

Unit 6 - Energy

Teacher’s note pg 56

Activity 6.4: Uses of fossil fuels

Learning outcomes:
By the end of the activity, pupils should be able to:
• List some fossil fuels
• State that fossil fuels are sources of energy for various activities
• Explain some uses of fossil fuels

Skills: observe pictures, relate to the items depicted, communicate their ideas in oral and tabular
forms, literacy

Pupils have already learnt about fossil fuel as a source of energy. They now learn about the uses
of fossil fuels.

After discussing in groups, pupils will fill the table 6.2 with appropriate answers.

Picture A How do we use the energy? Name of fossil fuel
Picture B To produce electricity Coal
Picture C To drive bus Petrol
Picture D To drive a speed boat Petrol
Picture E To drive a truck Petrol
Picture F To boil water
To cook food Natural gas
Natural gas

From this activity, pupils learn about some fossil fuels and the various ways in which fossil fuels are
used.

54

Unit 6 - Energy

Teacher’s note pg 57-58

Activity 6.5: Falling water is a source of energy
Learning outcomes:
By the end of the activity, pupils should be able to:
• Name three waterfalls in Mauritius
• State that falling water is a source of energy
• Explain that energy from falling water may be used to produce electricity
Skills: observe pictures, relate to the items depicted, communicate their ideas in oral and written
forms, literacy
Pupils are made to recall their experience if ever they have been to a waterfall (or watched in
movies or on the Internet). The idea of hearing loud sound and of seeing the water splashing
vigorously is explored. From this a link is made to the fact that falling water releases a large amount
of energy. This energy is used to produce electricity in Mauritius and other parts of the world.
Having studied about the sources of energy such as fossil fuels, falling water and food, pupils will
now learn about forms of energy.
This part of the activity is about recalling what was learnt in earlier classes. Pupils work in group to
observe and discuss the four examples given. After discussion they will fill the table to communicate
their answers. The first example is completed to help pupils in their discussion.
For the torch, pupils are taught that the source of energy is the cell that is put inside it. The form of
energy obtained from the torch is light energy.
For the leaves being blown by the wind, the source of energy is the wind. The form of energy in this
example is movement energy of the leaves.
For the wood stove, the source of energy is the dry wood. The forms of energy obtained are heat
and light energy. Heat energy is more important in this example as it is used in the cooking process.
For the burning of the charcoal, the source of energy is the charcoal. The forms of energy obtained
are heat and light.

55

Unit 6 - Energy9 10
8
Activity 6.4 Uses of fossil fuels
7
6
5
4
3
2
1
0

A: producing electricity B: transporting pupils C: driving a speedboat

D: carrying goods E: boiling water F: cooking food

The pictures show some uses of fossil fuels. Using the example given, complete Table 6.2.
Table 6.2

Picture A How do we use the energy? Name of fossil fuel
To produce electricity Coal

Picture B

Picture C

Picture D

Picture E

Picture F

56

Unit 6 - Energy

What I have learnt To extract something
means to remove it.
• Coal, petrol and natural gas are called fossil fuels.
• Fossil fuels are extracted from the Earth.
• Fossil fuels are used as energy sources.
• Petrol is used for transport of goods and people.
• Coal is used to produce electricity.
• Natural gas is used for cooking and heating.

Keywords to learn

fossil fuel petrol natural / cooking gas coal

9 10
8

7 Activity 6.5 Falling water is a source of energy
6
5
4
3
2
1
0

In Mauritius, we have many beautiful waterfalls. Name THREE of them using your Atlas.
1. ______________________ 2. ______________________ 3. ______________________

Have you ever been near a big waterfall?

What can you hear?_________________________

Falling water has a lot of energy. The higher the waterfall,
the more energy the falling water has.

waterfall

A dam stores water. The water that comes out has a lot
of energy.

You will learn in Grade 6 how falling water is used to
produce electricity in Mauritius.

dam

57

Unit 6 - Energy

Forms of Energy

Let us remember what we learnt in Standard III and IV.

torch leaves blowing

wood stove burning charcoal

Discuss with your friends which sources and forms of energy are shown above. Using
the examples given, complete Table 6.3.

Table 6.3

Object or Activity Source of Energy Form/s of energy
torch cells light

58

Unit 6 - Energy

Teacher’s note pg 60-61

Activity 6.6 Finding out about light energy

Learning outcomes:
By the end of the activity, pupils should be able to:
• State that the sun is not the only source of light energy
• State that light is a form of energy that allows us to see
• Identify and name sources of light energy
• Tabulate the sources of light energy shown in the pictures

Skills: observe pictures, relate to the items depicted, communicate their ideas in oral and tabular
forms, literacy

In this activity a set of varied examples of sources of light is given. Pupils are required to discuss in
groups about these sources of energy and tabulate them. One example is given to facilitate the
discussion among pupils.

The examples taken are: the source of light energy is wood
1. Burning wood the source of light is the fly (or the food eaten by the fly)
2. A light fly the source of light energy is the wax
3. Burning candles the source of light energy is the sun
4. The moon is shining the source of light energy is the wood
5. A burning matchstick the source of light energy is the oil
6. A lit oil lamp the source of light energy is the sun
7. The sun is shining the source of light energy is the magma
8. A volcano erupting the source of light energy is electricity
9. A lighting bulb

This activity is followed by a comparison between the sun and the moon. The focus of this activity is
that the moon shines as well as the sun but the moon does not produce light as the sun. Moonlight
is due to the light from the sun falling on the moon and being reflected from it. Thus, though we call
it moonlight, its source is still the sun.

59

Unit 6 - Energy

9 10
8

7 Activity 6.6 Finding out about light energy
6
5
4
3
2
1
0

1. Do you need to switch on the light during the day?_________________

Why?_____________________________________________________ The Sun
2. Is the Sun the only source of light energy?_________________________

3. Name TWO other sources of light energy.

a.___________________________ b._________________________________

Light energy is a form of energy that allows us to see.
The pictures below show different objects giving out energy in the form of light. Using
the example given, complete Table 6.4.

60

Table 6.4 Unit 6 - Energy

Giving out energy in the form of light Source of light energy
burning wood wood

Light energy from the Moon and the Sun

A: moonlight B: sunlight

1. Can you see light coming from the Moon in picture A? ____________________________
This light is called moonlight.
2. Can you see light coming from the Sun in picture B? _____________________________
This light is called sunlight.

Did you know?

The Moon does not produce its own light. The light from the Sun falls on the
Moon. It is this light that we see as moonlight.

Keywords to learn

form Moon Sun light moonlight sunlight 61

Unit 6 - Energy

Teacher’s note pg 63-64

Activity 6.7 Is the Sun a source of heat energy?

Learning outcomes:
By the end of the activity, pupils should be able to:
• State that we feel hot during the day due to the sun
• Use a thermometer to record temperatures
• Conduct an experiment to show that the sun is a source of heat energy
• Recognise that the sun is also a source of heat energy, along with light energy

Skills: experimentation, observation, communicate their ideas in oral and written forms, literacy

In this activity pupils will conduct a simple experiment to show that the sun is a source of heat
energy.

Before the experiment, the teacher explains about the safety aspects in the use of a thermometer.
As this instrument is fragile pupils are required to handle with care, under the supervision of the
teacher.

Pupils work in groups and use the thermometers provided to measure the temperature of air in
the shade of a tree and then the temperature of air in direct sunlight. Both measurements are
conducted for five minutes and this is checked using a watch. Pupils may use their watches.
In the table provided, pupils will record the values of temperatures in the shade and in direct
sunlight, both for five minute time interval. The values are then written in the table 6.5 for comparison.
Through further questioning and prompts, the teacher makes pupils understand that the air in
direct sunlight is hotter, that is, it has a higher temperature.

The conclusion drawn from this activity is:
The temperature in direct sunlight is higher. It is hotter in direct sunlight. More heat energy is obtained
from the sun when exposed to direct sunlight. The sun is a source of heat energy.

Further questions are also related to the fact that when we are exposed to direct sunlight, we feel
very hot so we need to move in the shade of trees or in vehicles or buildings.
Pupils also discuss on the desert being hot during the day due to the land being heated by the sun,
the absence of rain and due to the absence of trees to provide shade.

As a precaution, pupils are explained about the risk of becoming blind if staring at the sun with
naked eyes.

62

Unit 6 - Energy

9 10
8

7 Activity 6.7 Is the Sun a source of heat energy?
6
5
4
3
2
1
0

How do you feel during the day when the sun is shining brightly in the sky? ______________

In this activity, we will find out whether the Sun is a source of heat energy. We will measure the
temperature of the air.

Question

Is the Sun a source of heat energy?

What you need A thermometer A watch

A thermometer and a watch.

What you do

Hold the thermometer in the shade of a
tree for five minutes.
Use a watch to record the time.
Read the temperature of the air.
Record your observations in Table 6.5.

I remember tIhmeurmstohmoeldteaTanhr diwntkihthinckare.
It is fragile.

Hold the thermometer in direct sunlight for
five minutes.

Use a watch to record the time.

Read the temperature of the air.

Record your observations in Table 6.5.

63

Unit 6 - Energy

What I observe

Table 6.5

Temperature of the air

in the shade in direct sunlight

Which place has a higher temperature?_____________________________________
Which place is hotter?___________________________________________________

I conclude from my observations

The temperature in direct sunlight is _________________ (higher / lower) than the
temperature in the shade of a tree.
Therefore, it is _______________ (hotter / less hot) in direct sunlight.
We get ______________ (more / less) heat energy in direct sunlight.
The Sun _______________ (is / is not) a source of heat energy.

More Questions

1. Why do we move in the shade of trees when it is very hot?
_____________________________________________________________________
_____________________________________________________________________
2. Why is the desert very hot during the day? Give TWO reasons.
a._____________________________________________________________________
b._____________________________________________________________________

NEVER look directly at the Sun.
It can damage your eyes.
64

Unit 6 - Energy

Teacher’s note pg 66

Activity 6.8 Finding out more about heat energy

Learning outcomes:
By the end of the activity, pupils should be able to:
• State that our body is kept warm due to heat energy
• Recognise that heat energy is obtained from various sources
• Identify and name items giving off heat energy
• Discuss and tabulate the sources of heat energy given in pictures

Skills: observation, collaboration, communicate their ideas in oral and tabular forms, literacy

Pupils are required to discuss in groups about the pictures given. They have to identify the pictures
and then the source of heat energy depicted.

The answers are: the source of heat energy is the magma
1. A volcano erupting the source of heat energy is the coal
2. Burning of coal the source of heat energy is the natural gas
3. A gas stove the source of heat energy is electricity
4. An electric iron that is on the source of heat energy is the sun
5. The sun the source of heat energy is the fire
6. A lit matchstick the source of heat energy is the fire
7. Wood burning the source of heat energy is electricity
8. A hair drier the source of heat energy is electricity
9. A microwave oven

It should be noted that electricity has been stated as a source of energy. Actually electricity is a
secondary source of energy, after being produced through various means.

65

Unit 6 - Energy9 10
8
Activity 6.8 Finding out more about heat energy
7
What form of energy keeps us warm? ___________________________6
Heat energy is a form of energy that keeps humans and most animals warm.5
Heat energy can also make things become very _____________(hot / cold).4
Heat energy is obtained from different sources.3
The pictures below show different objects giving out energy in the form of heat. Using the2
example given, complete Table 6.6.1
0

Table 6.6

Giving out heat energy Source of heat energy
A volcano in eruption The magma / lava

66

Unit 6 - Energy

Teacher’s note pg 69-70

Activity 6.9 Finding out about movement energy

Learning outcomes:
By the end of the activity, pupils should be able to:
• State that objects need energy to move
• Demonstrate understanding that humans and animals also need energy to move
• State that for anything small or big to move energy is needed
• Infer that movement energy is possessed by anything in motion

Skills: observation, collaboration, draw information from pictures, communicate ideas in oral and
tabular forms, literacy

In this activity, pupils start by answering the simple question ‘what helps objects to move?
Answers are elicited from pupils until they are able to say ‘energy is needed by objects to move.’
The teacher states that this form of energy that allows objects, animals and humans to move is
called movement energy. This energy is obtained by animals from the food that they eat.

Two examples are given for further discussion. Pupils are allowed to discuss in groups and suggest
answers to the questions set. The first one is the sailing boat. Pupils are expected to say that wind is
moving this boat so the source of energy is wind.

For the second example, pupils recognise that after a big cyclone, there are lots of damages
caused to the house. The trees are uprooted and the roof is blown away by strong winds. They
conclude that wind has a lot of energy.

To consolidate the understanding of movement energy, five situations have been presented to
pupils. They discuss in groups and identify the source of energy. Their answers are recorded in the
table.

Expected answers are:
1. The windmill is moved by the wind; the source of movement energy is wind
2. The bird is flying; the source of movement energy is the food eaten by the bird
3. The fish are moving; the source of movement energy is food
4. The aeroplane is flying; the source of energy is petrol (fossil fuel)
5. The fan is turning; the source of movement energy is electricity

It should be noted that anything that moves has movement energy. The kind of movement may
be in a straight line, in a curve, oscillating, moving very fast or very slow, spin, even in an irregular
manner. All these are examples of movement energy.

So far pupils have learnt that heat, light and movement are forms of energy.

67

Unit 6 - Energy

Teacher’s note pg 70-71

Activity 6.10 Finding out about chemical energy

Learning outcomes:
By the end of the activity, pupils should be able to:
• State that food contains energy and it is called chemical energy
• Identify and name other items such as fossil fuels and wax that contain chemical energy
• Infer that coal and charcoal are different things
• Tabulate different ways in which chemical energy is used

Skills: collaboration, observation, draw information from pictures, communicate ideas in oral,
written and tabular forms, literacy

Pupils have already learnt that food is a source of energy. In this activity they are required to state
that the form of energy obtained from food is called chemical energy. Apart from food, there are
other materials that contain chemical energy. Here the examples of oil and wax are given. Pupils
recall that in a burning candle the chemical energy is converted into light and heat.

Pupils also learn that chemical energy is stored in fossil fuels. When fossil fuels are burnt the chemical
energy is transformed into heat and light. Pupils conclude that chemical energy is a form of energy
that is stored in food, oil, wax and fossil fuels. Chemical energy is also stored in coal and charcoal.
In fact, coal and charcoal are different things. Charcoal is obtained from fresh wood whereas coal
has taken millions of years to form underground from dead animals and plants. Coal is extracted
from mines.

Next part of the activity is about identifying various sources of chemical energy and discussing on
the uses of these sources in everyday life. Some probable answers are given below.

Source of chemical energy How we can use it
food to work
wax
wood to produce light
cells to cook food
to light a torch
bagasse
petrol to produce electricity
oil to drive cars
to light lamps
natural gas to cook food

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9 10 Unit 6 - Energy
8
Activity 6.9 Finding out about movement energy
7
6What helps objects to move? _________________________________
5Movement energy is the form of energy that any moving object has.
4Animals that run, crawl, swim or fly have movement energy.
3What is the source of their movement energy? The food animals eat provides them with energy
2to move.
1
0 What is moving this sailing boat? ___________________
What is the source of its movement energy?
_________________________________________________

After a big cyclone, the rooftop of this house has been blown away.
Strong winds can also uproot trees as they have a lot of movement
energy.
The pictures below show the different objects having movement energy. Using the
example given, complete Table 6.7.

69

Unit 6 - Energy Source of movement energy
winds
Table 6.7
Object/animal having movement energy
windmill

What I have learnt9 10
8
Light, heat and movement are forms of energy.
7 Light, heat and movement energy can be obtained from different sources.
6
5 Activity 6.10 Finding out about chemical energy
4
3Food gives us energy. People and animals eat different kinds of food. Plants make their own food.
2What form of energy is stored in food? _____________________________________________
1You have seen an oil lamp or a candle burning.
0What form of energy is stored in oil and wax? ________________________________________
You found out that fossil fuels are important sources of energy. What form of energy is stored in fossil
fuels? ________________________________________
Chemical energy is a form of energy that is stored in food, cells, batteries, oil, wax and
fossil fuels.

Did you know?

Coal and charcoal are two different things. Coal is a fossil fuel obtained from
the Earth through mining. Charcoal is obtained from wood that is partly burnt.

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Unit 6 - Energy

The energy stored in all the things below is called chemical energy. Using the example given,
complete Table 6.8.

Table 6.8 How we can use it
to work
Source of chemical energy
food

71

Unit 6 - Energy

Teacher’s note pg 73-74

Activity 6.11 Finding out about sound energy

Learning outcomes:
By the end of the activity, pupils should be able to:
• Identify and name sources of sound in the environment
• Infer that sound is a form of energy
• State that sound energy allows us to hear and communicate
• Classify sources of sound into categories such as soft, loud or both soft and loud

Skills: collaboration, observation, draw information from pictures, communicate ideas in oral,
written and tabular forms, literacy

In this activity pupils are required to keep silence for a few seconds in the classroom and listen to
what they can hear. Then they write four items that they can hear. Teacher follows the explanation
by making reference to the traffic on busy roads where loud sounds may be heard. It is then
concluded that sound is another form of energy and it is used to hear things around us (living and
non-living) and also to communicate.

Pupils will learn that sound energy is important for entertainment such as music and also to recognise
dangers around us. For example, if the driver of a vehicle or a pedestrian is making a mistake on
the road, another driver uses a horn to warn the person of possible dangers.

Pupils discuss in groups to find out that sound can be soft or loud depending on the source of
energy. Soft sound is pleasant whereas loud sound is unpleasant.

Next part of the activity is about pupils discussing in groups to classify sources of sound into soft,
loud or both loud and soft. The answers to the questions raised are given below.

Name of item Source of sound energy Soft or loud Can be both loud and soft
soft
bird singing food of bird can be both loud or soft
waterfall falling water soft can be both loud or soft
loud
clapping hands food can be both loud or soft
guitar food of people loud can be both loud or soft

aeroplane moving petrol can be both loud or soft
bell ringing food of people

loud speaker electricity
fire crackers chemicals
wolf howling food of the wolf

The following part is about three things that cannot be done without sound energy. Pupils are
allowed to express freely and suggest examples such as listen to music, talk to friends or use mobile
phone.

Pupils are also exposed to the fact that continuous exposure to loud sound can damage our ears
and can even make people become deaf.

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9 10 Unit 6 - Energy
8
Activity 6.11 Finding out about sound energy
7
6Remain silent for a few seconds and listen carefully.
5What can you hear? Identify the sounds you can hear. (You can try it at home or school).
41. I can hear birds chirping.
32. I can hear_________________________________________
23. I can hear_________________________________________
14. I can hear_________________________________________
05. I can hear _________________________________________
When you are on the road, listen to the traffic. You will hear loud sounds of buses and other
vehicles moving along the road. Sound is another form of energy.
Sound energy is a form of energy that allows us to hear and to communicate.
We use sound energy for communication, entertainment and to recognise dangers around
us.
Sound can be soft and pleasant or loud and unpleasant.
We can obtain sound energy from different sources.
1. The following pictures show different sources of sound energy. Using the example

given, complete Table 6.9.

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Unit 6 - Energy

Table 6.9 Soft or Loud Can be both loud and soft
soft
Source of sound energy
bird singing

2. State THREE things you cannot do without sound energy.
a. I cannot listen to music without sound energy.
b. I cannot ________________________________________________________________
c. I cannot ________________________________________________________________

Did you know?

Continuous loud sound is a source of danger to us. It can affect our
health and damage our ears. We can even become deaf.

74

Unit 6 - Energy

Teacher’s note pg 76-77

Activity 6.12 Finding out about electrical energy

Learning outcomes:
By the end of the activity, pupils should be able to:
• Identify and name devices that use electrical energy to function
• Infer that electrical energy is another form of energy
• List sources of electrical energy
• State that electrical energy is produced by burning bagasse or coal

Skills: collaboration, observation, draw information from pictures, communicate ideas in oral and
written forms, literacy

Pupils start by identifying the devices given. These are the hair drier, electric iron and electric
kettle. They discuss in groups and suggest that electricity is needed for them to operate. Pupils
are made to notice the electric cables are used in all three items. Teacher explains that in these
wires electrical energy flows when there is a closed circuit and electrical energy is used by many
devices. For example, light bulbs, computers, rice cookers and others.

Through further discussions in groups using the pictures provided, pupils identify car battery, solar
panel and electric cells as sources of electrical energy.

Teacher probes further about how electrical energy is produced in Mauritius. Pupils are directed to
discussions that will make them say that electrical energy is obtained by burning of bagasse and
coal. Once the electrical energy is obtained it is distributed to houses and other buildings.

Teacher then concludes that in this unit various forms of energy have been studied and these are:
• Light energy
• Heat energy
• Movement energy
• Chemical energy
• Sound energy
• Electrical energy

Pupils also recall that there are various sources of energy and these are:
• Food
• Sun
• Falling water
• Fossil fuels (natural gas, petrol, coal)
• Batteries
• Wind
• Wood
• Wax
• Oil
• Charcoal

From these two lists pupils are able to say that a source of energy is different from a form of energy.

75

9 10Unit 6 - Energy
8
Activity 6.12 Finding out about electrical energy
7
6
5
4
3
2
1
0

1. Look at the above objects. Name them.
a. ___________________ b. ___________________ c. ______________________
2. What is needed to make them work? _______________________________________
3. What form of energy is needed? __________________________________________

Electrical energy is a form of energy that flows along electrical wires in a closed circuit.
You will learn more about circuits in Unit 8.
Electrical energy allows us to operate many devices such as light bulbs, computers, rice
cookers and other household items.

What are the sources of electrical energy?

car battery solar panel electrical cells
76

Unit 6 - Energy

Electrical cells, car batteries and solar panels are sources of electrical energy.

Burning fuels such as bagasse and coal can produce electrical energy in thermal power
stations. Once the electrical energy is produced, it is distributed to houses and other buildings.

bagasse coal

I conclude from my observations

Energy exists in the form of light, heat, movement, chemical, sound and electrical energy.
These forms of energy come from different sources around us.

What I have learnt

We can obtain energy from different sources such as cells, sun and falling water.
Energy can exist in various forms. These forms are:
• light energy
• heat energy
• movement energy
• chemical energy
• sound energy
• electrical energy
A form of energy is different from a source of energy.

Keywords to learn

sound movement chemical electrical cells wires

77

Unit 6 - Energy

Teacher’s note pg 80-85

Answers to end of unit exercises

Exercise 1

1. D coal
2. A bus
3. B comes from
4. A sources
5. C petrol and coal
6. C burning
7. A coal
8. B thermometer
9. B heat and light
10. D wind

Exercise 2

(i) heat and light
(ii) chemical
(iii) wind
(iv) heat
(v) light and sound

Exercise 3

(ii) natural gas and heat

Exercise 4

coal, natural gas and petrol

Exercise 5

1. I cannot watch TV without energy.
2. I cannot work with my computer without energy.
3. Without energy I cannot put the fan on when it is hot.
4. Without energy I cannot make ice in the refrigerator.

Exercise 6

Statements that are true:
• Wood is a source of energy.
• Electrical energy can be produced from falling water.
• Wind is a source of energy.
• Petrol is used to drive vehicles.

Exercise 7

• Drying of fish: sun
• Driving a car: petrol
• Cooking rice: wood

78

Unit 6 - Energy

Teacher’s note pg 80-85

Exercise 8
(i) Switching on a radio: sound energy
(ii) Burning of cooking gas: heat energy (and light)
(iii) Kicking a football: movement energy
Exercise 9
Any diagram in which the pupils draw an animal, human being or object that is moving. It may
be moving in a straight line, in a curve, oscillating or in an irregular manner
Exercise 10
a) Sun
b) In winter there is less sunlight or the sunshine is less bright
c) On the roof of houses
d) There will be less shadows and the device will heat well
Exercise 11
Heat
Petrol, coal
Petrol, coal, natural gas
Exercise 12
Horizontal: heat, movement, chemical
Vertical: sound, electrical, light

79

Unit 6 - Energy

End of Unit Exercises

Exercise 1

For each item, there is ONE correct answer. Draw a circle around the letter which shows
the correct answer.

1. Which of the following is a source of energy?

A light B sound C heat D coal

2. A non-living thing that uses energy to move is the____________.

A bus B horse C plant D cyclist

3. The source of energy is where the energy____________.

A goes to B comes from C stays D falls

4. The sun, food, wind and petrol are important____________ of energy.

A sources B forms C categories D types

5. _________________are examples of fossil fuels.

A bread and rice B bread and bagasse
C petrol and coal D coal and wood

6. We get energy by________________ fossil fuels.

A mixing B spilling C burning D moving

7. A source of energy NOT used at home is____________________.

A coal B wind C sun D natural gas

8. We measure temperature using a _________________

A stove B thermometer C watch D ruler

9. Burning charcoal gives out__________________.

A heat energy only B heat and light energy C light energy only D wind energy

10. Which of the following is not a form of energy?

A electrical B sound C chemical D wind

80

Unit 6 - Energy

Exercise 2

Complete the sentences by filling the blanks with the correct word.
(i) The forms of energy produced by the Sun are _____________________ energy and
_____________________energy.
(ii) Animals obtain _____________________ energy from food.
(iii) The source of energy used by a sailing boat is from the_____________________.
(iv) When cooking with wood, _____________________ energy is obtained.
(v) The forms of energy obtained in a TV set are _____________________ and
_____________________ energy.

Exercise 3

Which one of the following pairs contains a source AND a form of energy?
Tick (√) the correct answer.
(i) Sun, wind ( ____ ) (ii) Natural gas, heat ( ____ )
(iii) Cells, wood ( ____ ) (iv) Wood, diesel ( ____ )
(v) Heat, chemical ( ____ ) (vi) light, heat ( ____ )

Exercise 4

State three examples of fossil fuels.
1. ____________________ 2. ___________________ 3. __________________

Exercise 5

Using a complete sentence write down FOUR things that you cannot do without energy.
1._______________________________________________________________________
2._______________________________________________________________________
3._______________________________________________________________________
4._______________________________________________________________________

81

Unit 6 - Energy

Exercise 6 √

In the table below tick (√) the statements that are true.

Statement
1 Natural gas is a form of energy.
2 Wood is a source of energy.
3 Electrical energy can be produced from falling water.
4 A torch produces sound energy.
5 Wind is a source of energy.
6 Petrol is used to drive vehicles.
7 A cell contains movement energy.
8 Burning coal produces heat and electrical energy.

Exercise 7

State which source of energy may be used for the following activities:
(i) Drying of fish: _______________________________________________________
(ii) Driving a car: _______________________________________________________
(iii) Cooking rice: _______________________________________________________

Exercise 8

State which form(s) of energy is produced in the following examples:
(i) Switching on a radio: __________________________________________________
(ii) Burning of cooking gas: _________________________________________________
(iii) Kicking a football: _____________________________________________________

82

Unit 6 - Energy

Exercise 9

Be creative. Draw, colour and label a diagram to show an example where there is
movement energy.

Exercise 10

Study the diagram and answer the questions
that follow:

(a) State the source of energy that causes this
device to work.
________________________________________

(b) This device does not work properly in winter season. Explain why.
________________________________________________________________________
(c) What is the best place to keep this device?
________________________________________________________________________
(d) Explain your answer to (c) above?
________________________________________________________________________

83

Unit 6 - Energy

Exercise 11

Answer the following questions:
1. Give one FORM of energy obtained from Earth. _____________________

2. Give two sources of energy obtained from Earth.
1. ________________________ 2. ____________________________

3. Wood and charcoal are important sources of chemical energy. Name THREE other fuels that
store chemcial energy.

1. ______________________ 2. ______________________ 3. ______________________

Exercise 12

Complete the cross-word below. They are about all the forms of energy you learnt.

L

E ha
S t
M ee

n

c cl
84 l

Unit 6 - Energy

I check my progress

At the end of this unit, I can

• define energy.
• state what is a source of energy.
• state some sources of energy.
• list different forms of energy in a given situation.
• differentiate among sources and forms of energy.
• give examples of fossil fuels.
• state the uses of fossil fuels.
• carry out a simple experiment to show that the sun is a

source of heat energy.
• measure temperature using a thermometer.
• draw conclusions based on observations.
• show understanding of different forms of energy.
• solve simple problems on energy.

85

Unit 6 - Energy

Teacher’s note pg 87

Unit 7: Transformation of Energy
At the end of this unit, pupils should be able to:
• Identify sources of energy in various examples
• Identify forms of energy in various examples
• Explain the energy transformations taking place in some simple devices
• State some examples of energy transformations in everyday life
• Infer that energy can be transformed from one form to another
• Use a simple diagram to describe energy transformation
• State why we must save energy
• State ways to save energy
The aim of this unit is to enable pupils explore the forms of energy and sources of energy in various
examples and to explain the energy conversions (also called energy transformations) taking place.
It also helps pupils to understand how energy is wasted and how it can be saved.
In this unit, pupils will firstly recall what they have learnt in standard IV through their brief exposure
to energy conversions. Teachers need to consolidate these concepts learnt earlier.
Teachers should encourage pupils to engage in group discussions and to communicate their ideas
in various ways. Teachers are advised to encourage pupils to do follow-up activities at home, as
far as possible, taking care of safety aspects. This is very important as the home environment is
very different from the school environment and we can come across very different examples that
would enrich learners’ experiences. Even parents may be engaged in the learning experiences of
their children.

86

Unit 7 - Transformation of Energy

Transformation of Energy UNIT 7

In Unit 6, you learnt that energy exists in various forms. You named and identified different
forms of energy.
In this unit, you will learn that one form of energy can be transformed into another. You will
study about energy transformations in simple devices and in everyday life. You will also learn
why and how we must save energy.

At the end of this unit, you should be able to:

• identify sources of energy in various examples.
• identify forms of energy in various examples.
• explain the energy transformations taking place in some simple devices.
• state some examples of energy transformations in everyday life.
• infer that energy can be transformed from one form to another.
• use a simple diagram to describe energy transformation.
• state why we must save energy.
• state ways to save energy.

87

Unit 7 - Transformation of Energy

Teacher’s note pg 89

Activity 7.1: recalling transformation of one form of energy into another
Learning outcomes:
By the end of the activity, pupils should be able to:
• State the source of energy in various examples given
• Explain how energy is being converted from one form to another in the examples given
Skills: observe pictures, relate to the activities depicted, communicate their ideas in oral, written
and pictorial means, literacy
This is a recall activity to test prior knowledge of pupils before additional conversions of energy are
taught.
At the end of this recall activity pupils will be able to identify forms of energy that they have
already learnt in standard IV and the conversion of energy taking place.
Example 1 shows a moving car
In the car, the source of energy is petrol. Chemical energy is stored in the petrol. When the car
moves, the chemical energy in the petrol is converted into movement energy.
Example 2 shows a man digging a hole
For the man, the source of energy is food. Chemical energy is stored in the food. When the person
is digging, chemical energy in the food is transformed into movement energy.
Example 3 shows a sailing boat
For the boat to move, it needs energy. This energy is provided by the wind. Movement energy of
the wind is used to move the boat. The energy transformation is from movement energy of the
wind to movement energy of the boat.

88

Unit 7 - Transformation of Energy

9 10 Activity 7.1 Recalling transformation of one form
8 of energy into another

7
6
5
4
3
2
1
0

In Standard IV, you described some examples of energy transformations in everyday
life. Let us recall a few examples.

Example 1 A moving car

Energy from petrol movement energy of a car

What is the form of energy stored in petrol?

Therefore in a moving car, we have the energy transformation moving car
given below:

Chemical energy movement energy of a car

The diagram above shows how one form of energy is transformed
into another form of energy

Example 2 A man digging a hole

Energy from food movement energy of man

What is the form of energy stored in food?

Write down the energy transformation for a man digging a hole:

A man digging a hole

Example 3 A sailing boat

Energy from the wind movement energy of sailing boat

What form of energy is present in the wind?

Write down the energy transformation for the sailing boat.

sailing boat
89

Unit 7 - Transformation of Energy

Teacher’s note pg 91-93

Activity 7.2 What is energy transformation?

Learning outcomes:
By the end of the activity, pupils should be able to:
• Recognise how to represent an energy transformation pictorially
• explain the conversion of energy in various instances involving animals, humans and objects

Skills: communicating energy conversion in a pictorial form, literacy

This activity is about energy transformation in different instances involving humans, animals and
even objects.

The forms of energy are first recalled and listed as a pre-requisite.

Then different types of diagrams used to depict energy transformation are learnt. This part is
important as various types of transformation of energy occurs. In some cases there is a simple linear
transformation where one form of energy is converted into another single form, whereas in some
other examples, one form of energy is transformed into more than one form. In other examples,
there is an intermediate stage, where the initial form of energy is first converted to one form and
then to several other forms. All these are first learnt, and then concrete examples are studied.

In the ‘Did you know’ section, special reference is made to the fact that energy transformation
can also take place in the human body.

In the case of human beings, the food that we eat provides chemical energy. This energy is then
converted into heat, movement and sound energy when we do exercise, work and play.
For example, while the adults are jogging, chemical energy from food is converted into movement
and sound energy. When the children are playing, chemical energy from food is converted into
movement energy and also sound energy.

For the bird, the chemical energy obtained from food is converted into movement energy while
it is flying. However, when the bird is chirping, chemical energy from food is converted into sound
energy.

We normally fill petrol in cars (and other vehicles) for them to be able to move. In the moving car,
chemical energy from petrol is converted into movement energy. Part of the chemical energy
from petrol is also converted into electrical energy. The latter is stored in the battery of cars as
chemical energy. This chemical energy is converted into light energy in the bulbs and into sound
energy in the speakers and in the hooters. The speakers in the car are normally found in the doors
and behind the passenger seat. Also note that a large amount of the chemical energy changes to
heat energy. This is why you can feel it is hot when you come near the engine part of any vehicle
that runs with petrol or gas.

90