Energy and Change [Grade 5 English]

WESTERN CAPE PRIMARY SCIENCE PROGRAMME

ENERGY ANDCHANGE

GRADE 5

We welcome the wide use of these materials. Please acknowledge the PSP. ©PSP 2002

An example of a short learning programme in the Natural Sciences and Technology

ACTIVITIES1: Making a class poster to show

the different forms of energy

2: Electrical energy travels throughdifferent materials

3: Making electrical circuits inorder to get heat, light, soundand movement energy

4: The mains electricity alsosupplies heat, light, sound andmovement energy

5: How much electrical energy doappliances use from the mainsupply?

6: Where does the main electricitycome from?

7: How do we use electricity safely?

DEVELOPED BY WESTERN CAPE PSP TEAM AND TEACHERSThis learning programme will work towards the following learning outcomes in the Natural Sciences

K LO1: Scientific InvestigationsThe learner will be able to act confidently on curiosity about natural phenomena, and to investigate relationships and solve problems in scientific, technological and environmental contexts

K LO2: Constructing Science KnowledgeThe learner will know and be able to interpret and apply scientific, technological and environmental knowledge

K LO3: Science, Society and the EnvironmentThe learner will be able to demonstrate an understanding of the interrelationshipsbetween science and technology, society and the environment.

Course presented by Rose Thomas, Shane Nzwane and Sandra Mahote

Booklet designed by Welma Odendaal and illustrated by Janet Ranson and Nicci Cairns

Western Cape Primary Science Programme

Edith Stephens Wetland Park

Lansdowne Road

Philippi 7785

PO Box 529Howard Place7450

Tel: 021 691-9039 Fax: 021 691-6350

e-mail: [email protected]

website: www.psp.org.za

Contents• This booklet illustrates an example of a short learning programme for Grade 5.

• It develops concepts, skills, attitudes and language in a step-wise fashion.

• It includes activities and tasks for learners, teacher tasks, support materials and assessment suggestions.

2 . . . . . . . . . .Activity 1 Making a class poster to show the different forms of energy

4 . . . . . . . . . .Activity 2 Electrical energy travels through different materials

8 . . . . . . . . . .Activity 3 Making electric circuits in order to get heat, light, sound and movement energy

12 . . . . . . . . .Activity 4 We also get heat, light, sound and movement energy from the main supply

14 . . . . . . . . .Activity .5 How much electrical energy do appliances use from the main supply?

17 . . . . . . . . .Activity 6 Where does the main electricity come from?

18 . . . . . . . . .Activity 7 How do we use electricity safely?

22 . . . . . . . . .Suggested workscheme

23–26 . . . . . .Assessment sheets

27 . . . . . . . . .Codes for assessment

Task cards to photocopy

28 . . . . . . . . .Activity 2 Which materials can electricity flow through?

30 . . . . . . . . .Activity 3 Making electric circuits to get heat, light, sound and movement energy

31 . . . . . . . . .Activity 4 Light , sound , movement and heat energy

32 . . . . . . . . .Activity 5 How much electrical energy do appliances use from the main supply?

33 . . . . . . . . .Fact sheet: How much electricity is used by our appliances?

34 . . . . . . . . .Activity 7 A The 3-pin plug

35 B Using electricity safely in the home

Support materials

37 . . . . . . . . . . . . .Safety in the home

38 . . . . . . . . . . . . .How light bulbs work

38 . . . . . . . . . . . . .Background information about batteries

39 . . . . . . . . . . . . .Batteries and cells

40 . . . . . . . . . . . . .Background information about Earthing and electrical shocks

Back page . . . . . .Mindmap about energy and change

2

Making a class poster to show thedifferent forms of energy

Assist learners to find pictures from newspapers and magazines to make aposter. Assist them to identify the different forms of energy in thepictures.

• Energy exists in different forms (there are different types of energy – heat, light, sound, movement, electricity). There is also nuclear (atomic) energy and stored energy but we do not expect to cover these in this activity.

Forms of Energy

movement energy

heat energy

heat energy

electric energy

sound energy

light energy

NOTE:

We also get nuclear

energy and stored

energy, but it is not

expected that we

deal with this at this

stage.

Activity 11

Teacher task

Key concepts

3

Work in groups1. Collect pictures from magazines & newspapers to show the different

types of energy.2. Make a poster on the wall of the classroom.3. Write sentences about the different types of energy, e.g waves have

movement & sound energy.

Making a class poster to show the differentforms of energy

What we want to assess What we expect from learners

Making a poster to show The poster must have:different forms of energy a a heading e.g. ‘Different Forms of

Energy’a pictures that illustrate different forms

of energy such as sound, heat, light, movement, electricity

a labels that name the form of energy next to each picture

Writing sentences about the The sentences must:different forms of energy a explain what form of energy is

shown in the picture, for example:– waves in the sea have movement

energy– the motor car has movement

energy– the iron uses electrical energy– the fire has heat energy

a the sentences must make sense

Learner task

4

Electrical energy travels throughdifferent materials

1. Give each group of learners a torch battery (electrical cell), a torchlight bulb, and two pieces of insulated electrical wire.

2. Ask learners to make the bulb light up using that apparatus. Check tosee that the learners can make a circuit that will light the bulb.

3. Introduce the word ‘circuit’ and show the learners how the electricitytravels around the circuit from one end of the battery along the wires,through the light bulb and back to the other side of the battery. Asklearners to show you with their fingers on their circuit. See supportmaterials about light bulbs (page 38).

4 After learners have made the circuit with a light bulb they test differentmaterials to see if they conduct electricity. They do this by making acircuit as shown below:

• Some materials conduct electricity – they are called conductors• Some materials do not conduct electricity – they are called

insulators• Electricity will only flow in a circuit made of materials that conduct

electricity

light bulb

cell

electricity flow

wire

5. Introduce and explain the words ‘conductor’ and ‘insulator’.Learners connect the material they want to test into the circuit with thelight bulb. If the light bulb shines, the material is a conductor (it letselectricity flow through it). If the light does not shine then the materialis an insulator (it does not let electricity flow through it).

6. Give the learners the materials to test as shown on the task card.

light bulb

cell

electricity flow

wirenail

Activity 22

Key concepts

Teacher task

5

Task card

Which materials can electricity flowthrough?

A.1. Use the apparatus to make the light bulb light up. 2. Draw a diagram to show how you made the light bulb light up.

3. Why did the bulb light up?

Because electricity went through the light bulb.

B.1. Now, make a circuit like this.

2. Does the light bulb light up?

Yes3. Did electricity flow through the circuit?

Yes4. Does the nail conduct electricity?

Yes

NOTE: Let the learnerscomplete Abefore youhand out B.

light bulb

cell

electricity flow

wire

Learner task Task card tophotocopy, page 28.

light bulb

cell

electricity flow

wirenail

6

Materials for Does the bulb light up? Did the material let Is the material testing Yes/no the electricity through? an insulator

Yes/no or a conductor?

nail yes yes conductor

paper clip (metal) yes yes conductor

metal coin yes yes conductor

wooden clothes peg no no insulator

plastic bottle top no no insulator

metal wire yes yes conductor

metal spoon yes yes conductor

plastic spoon no no insulator

a piece of glass no no insulator

a plastic button no no insulator

5. Now test some more things to see if they let the electricity flowthrough. Then record your results on the table:

Discuss with learners what happened when they tested different materials.

They should find that only metals are conductors while plastics, wood,stone and other non-metals are insulators.

Write a short report on what you did:

Today we tested materials to find out if they are conductors orinsulators.

We found out that nails, wires, metal cans, paper clips and metal

spoons conduct electricity. They are all made from metal. They are

all conductors. .

We also found out that clothes pegs, plastic bottle tops,

plastic spoons, plastic and glass do not conduct electricty.

They are insulators.

Teacher task

Learner task

Learner task

(continued)


A Using apparatus to make a circuit in which The learners must:a bulb lights up a successfully connect a light bulb into the

circuit so that it lights upa draw a diagram of the circuit showing the

following:

a explain that the light bulb lights up because it is connected into an unbroken circuit that allows electricity to flow through the bulb

B Testing different materials to find out if they The learners must:conduct electricity and writing a report a test the different objects made of different

materials by connecting them in a circuit with a light bulb

a correctly record their observations on the table as they are doing the test

a write a short report which correctly identifies those objects and materials that are insulators and those that are conductors of electricity, i.e. all metals conduct electricity, whilst wood, glass, paper, plastic and rubber are insulators

7

Electrical energy travels through differentmaterials

light bulb

cell

flow of electricity

wire

oh, i see. only metalthings conduct

electricity.

ActivityAAsssseessssmmeenntt 22

wire

paper clip

drawing pins

wire

wire

paper clip

drawing pins

wire

Switch in closed positionSwitch in open position

Making electric circuits to get light,sound, heat and movement energy

1. Provide learners with the following equipment to make electricalcircuits:– torch batteries– torch light bulbs– pieces of insulated copper wire– wire wool (steel wool)– small electric motors from old tape recorders and turntables– sucker sticks or wooden blocks– drawing pins– prestik– paper clips

2. Show learners how to make a switch using paper clips and wireattached to thick cardboard, a wooden stick or block. They will includea switch in each of the circuits that they make.

8

• We can get heat energy, light energy, sound energy and movement energy from electricity

• To get this energy from electricity we need to make an electrical circuit

• A switch is used to make and break a circuit • We can get electricity from a battery (an electrical cell)

Activity 33

Key concepts

Teacher task

9

Task card

Making electric circuits to get heat, light, soundand movement energy

1. Make three different electric circuits. Explain what happens whenyou close the switch.

CIRCUIT 1When I closed the switch

the light bulb lights up


the motor starts

and the fan turns.


the steelwool gets hot and melts.

Task card tophotocopy – page 30.

Learner task

10

1. Write a conclusion on the chalkboard with the help of the learners.

2. Help learners to understand that energy is stored in batteries and isreleased by a chemical reaction when the battery is connected into acircuit. Use the background information to help you – page 38–39.

3. The chemicals inside the battery store the energy. When we connectthe battery into a circuit the stored energy changes to electrical energyin the wires.

4. Assist learners to complete the following sentences.

Writing task Look at the circuits you made. Complete these summaries (energysequences) about your circuits.1. When you make a bulb light up stored energy in the battery changes

to electrical energy in the wires. This energy then changes to lightenergy in the light bulb.

2. When you start the motor and make the fan turn, stored energy in the battery changes to electrical energy in the wires. This electricalenergy then changes to movement and sound energy in the motorand fan.

3. When you heat up some steelwool stored energy in the batterychanges to electrical energy in the wires. This electrical energy thenchanges to heat energy in the steelwool.

CONCLUSION1. When I closed the switch, the electrical

energy flowed from the battery to thelight bulb and back to the battery. This iscalled an electrical circuit.

2. I can get heat, light, sound and movementenergy from electricity. The electricitycomes from the battery.

Teacher task

Learner task

11


Making electric circuits in order to get The learners must use the apparatus to makeheat, light, sound and movement energy. a a circuit which lights up a bulb

a a circuit which turns a fan and motor (the fan and motor will also make a sound)

a a circuit which heats a piece of steel wool

The learners must be able to manipulate the equipment with confidence

Drawing circuits and writing an explanation The drawings must show clearly: to say what happens when the switch a how all the components in the circuits are is closed connected to each other

a what happens when the circuit is connected,e.g. radiating lines around the light bulb that show it is shining

The sentences must say:a that the light bulb lights upa that the motor turns and rotates the fana that the steelwool gets hot

Completing summaries about the These are the completed summaries (sequences): sequence of energy flow a Stored energy in the battery changes to electrical

energy in the wires. The electrical energy then changes to light energy in the light bulb

a Stored energy in the battery changes to electrical energy in the wires. The electrical energy then changes to movement energy in the motor and fan

a Stored energy in the battery changes to electrical energy in the wires. The electrical energy then changes to heat energy in the steelwool

Making electric circuits in order to get heat,light, sound and movement energy


12

We also get heat, light, sound, andmovement energy from the mainelectricity supply

1. Bring a radio which can use the energy of batteries but which can alsorun off the main electricity supply. Also bring some electricalappliances which use energy from the main supply only.

2. Discuss with learners what they know about batteries and about themain supply. See background information on the batteries and themain supply on page 38–40.

Writing task

• We get electricity from a main electricity supply which comes to our homes from a power station

• The main electricity flows in a circuit from the power station to our house and into the appliances and back to the power station

• The electricity from the main supply is very powerful and can be dangerous. So it must be used correctly and carefully

Name of appliances What happens when I switch it on? What types of energy do we get from it?

Kettle the water gets hot and boils heat, sound and movement energy

Hair dryer (or heater) it makes a noise and gives out hot air heat, sound and . movement energy

Food mixer or fan the beaters or blades go round and it movement and sound makes a sound energy

Radio we can hear a sound sound energy

Lamp the light bulb lights up light and heat energy

Activity 44

Teacher task

Key concepts

Learner task

13

Complete these sentences:

1. When I switch on the kettle I get heat, movement and sound energy.

2. When I switch on a hairdryer/ heater I get heat, sound and movementenergy.

3. When I switch on a food mixer/fan I get movement and sound energy.

4. When I switch on a radio I get sound energy.

5. When I switch on a lamp I get light and heat energy.

We also get heat, light, sound, and movementenergy from the main supply


Completing sentences about The sentences should be completed as the energy we get when we follows:switch on appliances a when I switch on a kettle I get heat,

sound and movement energya when I switch on a hair dryer I get

heat, sound and movement energy. From a heater I get heat, movement and sound energy if it is a fan heater

a when I switch on a food mixer or fan I get sound and movement energy.

a when I switch on a radio I get soundenergy

a when I switch on a lamp I get lightenergy and heat energy

Learner task


14

How much electrical energy doappliances use from the main supply?

1. Collect pictures of electrical appliances. You will find these in thenewspapers especially towards the end of the month. Cut these out.

2. Hand out pictures to the learners and with the help of the learner taskcard, they must decide:– what is the main form of energy we get from each appliance?– how much energy (in Watts) does each appliance use?

3. Make a big chart on the chalkboard like this:

• We can get almost unlimited amounts of energy from the main supply

• Different appliances require different amounts of electrical energy to make them work

• We can tell how much energy an appliance needs by looking at the amount of electrical power it requires. The power is measured in Watts

• A Watt is how much electrical energy an appliance uses every second

Amount of energy used Light Sound Movement Heatevery second

10 Watt

100 Watt

250 Watt

500 Watt

750 Watt

1 000 Watt

2 000 Watt

3 000 Watt

ELECTRICAL APPLIANCES

Activity 55

Key concepts

Teacher task

15

it takes a lot ofenergy to make

things hot!

yes, but we don’t needmuch electrical energy to

get sound and light.

i wonder how muchenergy cell phones use?

Turn to page 16

4. Ask learners to place their pictures of appliances on the chalkboardto show the type of energy we get from it, and the amount ofelectricity it uses (in Watts).

Learner task Task card

How much electrical energy do appliances use from the mains supply?1. Place your picture on the class chart to show what energy you get

from your appliance and how much electricity it uses. Use the tablebelow to help you.

2. Look at the completed class chart and then answer these questions:a Which appliance uses the most energy? a Which appliance uses the least energy?


Answering the questions The answers must say:about how much electricity a that the most amount of electrical energy is used by appliances different appliances use such as: heaters, stove, kettles and hot plates

a that the least amount of electrical energy is used by radios, tape recorders, and clocks

a appliances that give us heat use the most energya appliances that give us light, movement and sound use the least

energy

16

The amount of energy appliances use

How much electrical energy do appliances use from the main supply?

3. Look at your chart again. Complete these sentences. Fill in the missingwords.

heat light sound movementa. Appliances use a lot of energy when they give us heat from electricity.b. Appliances use a little energy when they give us sound, light and

movement from electricity.

Learner task


Task card tophotocopy on

page 33.

17

Where does the main electricity comefrom?

With the help of the drawing below – ‘Where does the mains electricitycome from?’ – explain the following to the learners:The main electricity in our homes is produced in a power station.Wires connect the power station to our homes.When we plug in an appliance this brings the electricity from the powerstation to the wires in the appliance.When we switch on the appliance – this completes the circuit and allowsthe electricity to flow from the power station into the appliance and backagain.The electricity from the main supply is very powerful and can be verydangerous – so it must be used carefully and correctly.

• Main electricity is generated (produced) by power stations• The electricity travels in wires from the power station to our

homes and schools• When we want to use the electricity from the main supply we have

to connect the appliance by means of a 3-pin plug into the socket in the wall and switch on the electricity

• The 3-pin plug has three wires: the brown and blue wires connect to the main circuit, the yellow and green wire goes into the Earth and safely discharges dangerous electricity

Where does the main electricity come from?

power station

wall of house

The two wires (brown and blue) make a complete circuit from the power station to the house into the appliance andback – so that electricity can flow.

Steam

brown wire (live)

blue wire (neutral)

Earth wire (green/yellowl)

The Earth wire is buried in theground outside the house

The Earth wire takes excesselectrical energy safely intothe ground.

Activity 66

Key concepts

Teacher task

18

How do we use electricity safely?

1. Hand out the information about ‘Safety Inside the Home’ – page 37.2. Supply the learners with 3-pin plugs, electrical cord and screwdrivers

(use an appliance with its wires and plug. The learners can unscrewthe plug, then they can wire it correctly again.)

3. Hand out the questions about ‘Why are there three wires?’ Getlearners to discuss these questions in groups.

4. Introduce the idea of ‘Earthing’. Use the background information about‘Earthing’ to help you – page 40.

5. Introduce the terms ‘Electrical Shock’ and remind the learners aboutinsulators and conductors. Explain that although the wires in the cordare conductors they are encased in plastic insulating material whichprotects those using the appliances from being electrocuted (gettingan electric shock). Use the background information about electricalshocks to help you – page 40.

Task card

A. The 3-pin plug1. Wire up the 3-pin plug correctly like this:

2. Discuss the questions on the paper called ‘Why are there three wires?’3. Colour in the 3 wires in their proper colours.

• Most electrical appliances use energy from power stations• Many electrical appliances use a lot of energy and therefore it is

dangerous to use them incorrectly• An appliance must always be connected to the mains supply by

means of a 3-pin plug• The 3-pin plug must be correctly wired up to the appliance• Electrical wires are covered with insulating material to protect the

people using the appliance from being electrocuted (getting an electrical shock)


page 34.

blue – neutral

green/yellow – Earth

brown – live

Activity 77

Key concepts

Teacher task

Learner task

19

Why are there three wires?

1. Facilitate a class discussion about why there are three wires in the 3-pin plug making sure that the learners can answer the questions.

2. Cut out the pictures and sentences from the safety information – page37, and put them into envelopes for the learners.

Task card

B Using electricity safely1. Look at the pictures of people doing dangerous things with electricity.

Discuss:a What is dangerous in each picture?a What will happen to you if you do these dangerous things withelectricity?

2. Match each picture with the correct sentence and then put thesentences back into the envelope again.

3. Now write your own safety rules for when you use electricity.

don’t do don’t


page 35.

Leerdertaak

Learner task

(continued)

Do not insert bare wiresinto electrical sockets

Always use a correct plug.To remove – or insert:switch off first and holdonto the plug.

Do not use damaged cords– replace immediately

• The blue wire is calledthe Neutral wire.

• Another name for the green/yellowwire is the Earth wire

• If the green/yellow wire comesloose then there will be noconnection to the safety wire thatgoes into the ground. This takesexcess current to the Earth if theappliance is faulty.

• The wires are coated in plastic toinsulate them so that we are protectedfrom the dangerous electrical energy.

• If the brown orblue wire comesloose, then thiswill break thecircuit. Theelectrical currentwill not be able torun in the wires.The appliance willnot work becauseit will have noelectricity supply.

• The cover is made fromplastic to insulate the wireand protect us from thedangerous electricalcurrent. Inside the plasticare three wires – the Livewire, the Neutral wire andthe Earth wire.

• Another name forthe brown wire isthe Live wire.

20

1. Make sure that my hands are dry before I touch any electrical plugs.2. - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

3. - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

4. - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

5. - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

6. - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

7. - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Rules for using electricity safely at home When I want to use electricity safely I must:task

Learner task

(continued)

4. Finally draw a picture of an electrician working. Remembereverything you have learned about using electricity safely.


Wiring up a 3-pin plug The learners must:a use the screwdriver confidently to wire up the pluga attach the wires securelya attach the green/yellow Earth wire to the earth pin, the blue wire

to the neutral pin and the brown wire to the live pin

Answering questions about The learners must show they understand that:the reason why there are a the brown live wire and the blue neutral wire become connectedthree wires into the circuit from the power station when we switch on the

appliance. If one of these wires comes loose there is no longer a complete circuit and the electricity stops flowing

a a large amount of electrical energy flows through the live wirea the green/yellow earth-wire becomes connected to a wire that

goes into the ground when we switch on the appliance.a the Earth wire is there to protect people from getting electric

shocks. If it becomes disconnected then there is no safe connection from the appliance to the ground. This is dangerous if the appliance develops a fault

a the electrical wires are made from copper, a metal that conducts electricity very well

a the wires are covered with plastic that does not conduct electricity to prevent electricity escaping and causing shocks

Writing their own safety The learners must be able to:rules for using electricity a identify dangerous ways of working with electricity, e.g. putting

bare wires into a plug socketa say what they think will happen to them if they use electricity in

dangerous waysa write a set of safety rules to warn people about the dangers

they have identified

Drawing a picture of an The drawing must show:electrician working a the electrician wearing appropriate dress e.g. a uniform, wearing

shoes with thick soles, wearing rubber gloves, etca appropriate tools used by an electrician, e.g. a ladder to reach

the power lines, a screwdriver, etca doing some kind of work that an electrician might do, e.g. fixing

a plug, laying electrical cables in the road, etc

21

How do we use electricity safely?Activity

AAsssseessssmmeenntt 77

22

PERIOD 1Activity 1

• Learners collect pictures ofdifferent types of energyand make a poster on theclassroom wall. (50 min)

PERIOD 2Activity 1 (cont.)

• Learners write sentencesabout the different types ofenergy.

PERIOD 3Activity 2

• Learners make a circuit tomake a bulb light up. (10 min)

• Learners test differentmaterials to see if they areinsulators or conductors ofelectricity. (40 min)


• Learners and teacherdiscuss the results of theinvestigation aboutconductors and insulators.(20 min)

• Learners write a shortreport. (20 min)

PERIOD 5Activity 3

• Learners make switchesand electrical circuits toget heat, light andmovement. (35 min)

• Learners write a shortconclusion. (15 min)


• Teacher and learnerdiscussion about batteriesand how they work. (20 min)

• Learners write summariesabout the circuits theymade. (20 min)

PERIOD 7Activity 4

• Teacher introduces a radiothat uses batteries andmains electricity. (10 min)

• Learners recordobservations about energyand different appliances.(35 min)


• Learners completesentences about energyand appliances. (15 min)

• Teacher helps learners tocorrect their sentences.(20 min)

PERIOD 9Activity 5

• Learners sort and displaypictures of differentappliances according tohow much electricity theappliances use and whatform of energy they supply.(40 min)


• Learners write to answerquestions about the classdisplay. (15 min)

Activity 6

• Teacher explains howelectricity gets from thepower station to anappliance in our homes(using the diagram of themains supply). (30 min)

PERIOD 11Activity 7

• Learners wire up three pinplugs. (50 min)


• Learners discuss thequestions about why thereare three wires.(20 min)

• Teacher and learnersdiscuss the importance ofhaving live, neutral andearthing wires in a plug.(20 min)

Suggested work scheme for the grade 5 learning programme

ENERGY AND CHANGE


• Learners match pictures ofpeople using electricitydangerously with theircorrect sentences. (30 min)

• Learners begin to writetheir own electricity safetyrules. (15 min)


• Learners complete thewriting of their safety rules.(30 min)

• Learners draw a picture ofan electrician working,taking into accounteverything they have learntabout electricity. (20 min)

Total time for this Learning Programme = 14periods @ 50 min per period = 11,6 hrs. This isthree weeks’ work. (Recommended for NaturalSciences and Technology = 4 hrs per week)

28

light bulb

cell

electricity flow

wirenail

TASK CARDSPhotocopy for learners

Activity 2

Which materials can electricity flow through?

A1. Use the apparatus to make the light bulb light up.2. Draw a diagram to show how you made the light bulb light up.

diagram

3. Why did the bulb light up? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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

B 1. Now make a circuit like this.

29

2. Does the light bulb light up?

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3. Did electricity flow through the circuit?

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4. Does the nail conduct electricity?

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5. Now test some more things to see if they let the electricity flow through.

Record your results on the table:

Materials for Does the bulb light up? Did the material let Is the material testing Yes/no the electricity through? an insulator

Yes/no or a conductor?

nail

paper clip (metal)

metal coin

wooden clothes peg

plastic bottle top

metal wire

metal spoon

plastic spoon

a piece of glass

a plastic button

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Task card

Activity 3

Making electric circuits to get heat, light, sound and movement energy

1. Make three different electric circuits. Explain what happens when you close the switch.

CIRCUIT 1

When I closed the switch . . . . . . . . . . . . . . . . . . . .

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

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

CIRCUIT 2

When I closed the switch

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

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

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

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

CIRCUIT 3

When I closed the switch

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

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

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

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Name of What happens when What types of energy appliances I switch it on? do we get from it?

Kettle

Hair dryer (or heater)

Food mixer (or fan)

Radio

Lamp

Task card

Activity 4

Light, sound, movement and heat energy

1. Plug in some electrical appliances and switch them on.2. Record what happens:

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Task card

Activity 5

How much electrical energy do appliances use from the main supply?

1. Place your picture on the class chart to show what energy you get from your appliance andhow much electricity it uses. Use the table on the opposite page to help you.

2. Look at the completed class chart and then answer these questions:a Which appliance uses the most energy? a Which appliance uses the least energy?

3. Look at your chart again. Complete these sentences. Fill in the missing words.

heat light sound movement

a. Appliances use a lot of energy when they give us ——————————————— from electricity.

b. Appliances use a little energy when they give us ———————————————from electricity.

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APPLIANCEAmount of electrical energy it uses in watts

cell phone 3 W

radio/tape/CD player 15 W

fluorescent light 40 W

table lamp 60 W

sewing machine 75 W

fridge 150 W

fax machine 170 W

microwave oven 230 W

colour TV 340 Welectric drill 360 W

hair dryer 450 W

washing machine 500 W

vacuum cleaner 700 W

iron 720 W

toaster 1 000 W

electric frying pan 2 000 W

kettle 3 000 W

heater 3000 W

hot water cylinder 4 000 W

stove 8 000 W

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Activity 7

Task card A The 3-pin plug

1. Wire up the 3-pin plug correctly like this:

2. Discuss the questions on the paper called ‘Why are there three wires?’

3. Colour in the three wires in their proper colours

Why are there three wires?

What is the green/yellow wire for?

What is the blue wire for?

What is the brown wire for?

• Give another namefor the brown wire.

• Give another namefor the blue wire.

• Give another name forthe green/yellow wire.

• What happens if thegreen/ yellow wirecomes loose?

• Why are the wirescoated in plastic?

• What happens ifthe brown or bluewire comesloose?

• Why is the cover madefrom plastic?

What is inside the plastic?

blue – neutral

green/yellow – Earth

brown – live

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Activity 7

Task card B

Using electricity safely in the home1. Look at the pictures of people doing dangerous things with electricity.

Discuss:a What is dangerous in each picture?a What will happen to you if you do these dangerous things with electricity?

2. Match each picture with the correct sentence and then put the sentences back into theenvelope again.

3. Now write your own safety rules for when you use electricity.

Rules for using electricity safely at home

When I want to use electricity safely I must – e.g.

1. Make sure that my hands are dry before I touch any electrical plugs.

2. - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -3. - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -4. - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -5. - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -6. - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -7. - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

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a electrician working

Task card B4. Finally draw a picture of an electrician working. Remember

everything you have learned about using electricity safely.

37

SAFETY IN THE HOMEBe safe and happy with electricity by observing these simple rules.

Always wire yourplug correctly.

Do not use a damaged cord.Replace it immediately

Yellow/Green – Earth Brown – live Blue – neutral

Do not pull the plug by the cord.Switch it off first and remove byholding the plug.

Do not insert bare wires into electricalsockets. Always use a correct plug.

Do not overload a socket. Use a multiplug.

Never stick your fingers into a socket.Use a safety plug.

Never run an extension cord under a carpetor where people will walk or trip over it.Run the cord alongside the wall.

Never use electricity near water.Water and electricity do not mix.

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This is what a light bulb looks like inside.

glass bulb

tungsten filament

metal casing

plastic pin

metal pin

Teacher supportHow a light bulb worksA light bulb will light up when there is a

pathway for electricity to flow through it.

The electricity must flow from the one

end (pole) of the battery through the

electric wires, then through the filament

(thin wire) inside the light bulb and then

back to the other end (pole) of the battery.

When you connect a light bulb you must

make sure that there is one connection to

the metal pin at the bottom of the bulb

and another to the side metal casing

around the base of the bulb.

Electricity will always choose the

shortest and easiest pathway along

conductors. If the easiest route does not go

through the filament the bulb will not light

up.

Background information about batteries (cells)A torch battery is also sometimes called an electric cell. (Scientists use the

term ‘battery’ for a number of cells.) The most common battery that we

use is a dry cell battery, which has chemicals sealed inside a casing.

The chemicals inside react together. This chemical reaction produces

electricity, which can be used when the battery is connected into a circuit.

When its chemicals have finished reacting, it stops working and cannot

be recharged.

We use very small dry cell batteries to power digital watches and

pocket calculators. These have other chemicals inside them.

Other batteries can be recharged with electricity and used again such

as a cell (battery) for lap top computers. The car battery is made up of

several lead-acid cells and these can be recharged.

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Batteries and cells

Mercury battery

This type of battery is used for poweringdigital watches and pocket calculators. It is amercury battery.

An electrolyte is a liquid or moist substancewhich conducts electricity e.g. lemon juice,salt water, ammonium chloride paste.

Dry cell battery

The common dry cell batteryproduces a voltage of 1.5volts. The zinc forms thebattery casing. The electrolyteis ammonium chloride in theform of a moist paste.

Lead acid battery

The lead acid battery is used in cars. It is socalled because it has electrodes that are madeof lead, and the electrolyte is sulphuric acid.The battery consists of six sets of cells, whichproduce two volts each, for a total of 12 volts.

nickel-plated case

electrolyte

zinx powder

mercuric oxide and graphite

carbon rod (positive)

ammonium chloride paste

terminal

terminal

top-up cover

cell

casing

lead plates

positive plate

negative plate

zinc case (negative)

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BACKGROUND INFORMATION ABOUT EARTHINGMost houses, that have an electricity supply from the power station (main supply),

have a wire from the electricity board which goes through the wall and is buried in

the ground nearby. This is called an earthing wire. This is for the safety of those who

are using the electricity inside the house. When an appliance is faulty it can take

more electricity than it should. A faulty appliance is dangerous because when

somebody touching it can get burned or electrocuted. The earth wire conducts the

excess electricity in the faulty appliance down the wire into the ground where it

becomes harmless so that it will not cause a fire in the appliance or electrocute

somebody.

People’s bodies can conduct electricity. Without an earth wire the excess

electricity from a faulty appliance would flow through the person into the ground.

The person would get an electrical shock, or burns or even die from these. If there is

an earth wire, then the electricity will run through it as it is a better conductor than

a human body.

Many appliances are made of metal and use a lot of electrical energy. They must

have an earth wire. Other appliances are made of plastic (even some kettles and

irons) and do not draw a lot of electricity. They do not need an earth wire because

they are made of insulating material (plastic). If a plastic appliance is faulty, the

electricity can’t easily flow through the plastic to the person and electrocute

him/her.

BACKGROUND INFORMATION ABOUT ELECTRIC SHOCKSWhen a large amount of electrical energy passes through someone’s body we say

s/he has suffered an electrical shock or has been electrocuted.

The person usually falls down, sometimes s/he stops breathing for a short while,

and may suffer severe burns or he may be killed.

When a person has been electrocuted, the first thing to do is to switch off the

electricity at the main switch before you touch him / her to give help.

If the electricity has not been switched off and the electrocuted person is still in

contact with the electricity you could also be electrocuted when you touch him/her.

Documents

Energy and Change [Grade 5 English]