Matter and Materials [Grade 5 English]

MATTER AND

MATERIALSGRADE 5

We welcome the wide use of these materials. Please acknowledge PSP ©PSP 2008

Water is Precious1 Solids, liquids and gases

2 Mixing solids and liquids

3 Which solids are soluble and which solidsare insoluble in water?

4 Can we make a solid dissolve faster?

5 Can we get the solids back after we have

mixed them with water?

6 Water is a precious liquid

7 Making polluted water clean again

8 Making sewage water clean again

9 How do we get clean drinking water?

Western Cape Primary Science Programme (PSP)An example of a learning experience in the Natural Sciences

M&M5 (2008 reprint) 10/20/08 3:32 PM Page i

Courses presented by Rose Thomas and Nontsikelelo MahoteBooklet designed by Welma Odendaal Illustrated by Nicci Cairns and Janet Ranson

Western Cape Primary Science Programme

Edith Stephens Wetland Park

Lansdowne Road

Philippi, 7785

P O Box 24158

Lansdowne 7779

South Africa

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

e-mail: [email protected]

website: ww.psp.org.za

DEVELOPED BY WESTERN CAPE PSP team AND TEACHERSThese materials were written to support teachers in their work with learners around the content area of Matter & Materials. While this is not a complete work schedule, it offers possibilities for teachers to include other learning experiences and to extend and develop this further.

This example learning experience shows how you can work towards the following learning outcomes in the Natural Sciences.

A 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

A LO2: Constructing Science Knowledge

The learner will know and be able to interpret and apply scientific, technological and environmental knowledge

A LO3: Science, Society and the Environment

The learner will be able to demonstrate an understanding of the interrelationships between science and technology, society and the environment.

The PSP is grateful for support from PETROSA

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Section 1 – Learning Experiences

1 Solids, liquids and gases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1

2 Mixing solids and liquids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4

3 Which solids are soluble and which solids are insoluble? . . . . . . . . . . . . . . . . . . .8

4 Can we make a solid dissolve faster? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10

Assessment Task for LO 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12

5 Can we get the solids back after we have mixed them with water? . . . . . . . . . . .16

6 Water is a precious liquid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19

7 Making polluted water clean again . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22

8 Making sewage water clean again . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27


9 How do we get clean drinking water? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31


Suggested Work Schedule . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34–35

Section 2 – Teacher Resources

Task cards to photocopy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37-50

Assessment task cards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39, 48, 50

A3 diagrams and pictures to photocopy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54–57

Section 3 – Extracts from NCS

Core knowledge and concepts in Matter and Materials . . . . . . . . . . . . . . . . . . . . .60–61

Learning Outcomes and Assessment standards . . . . . . . . . . . . . . . . . . . . . . . . . .62–67

Contents

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Learning ExperiencesAssessment tasks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-33

LO1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12LO2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29LO3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32

Work Scheme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34-35

Section 1

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1

IntroductionRevise the 3 states of matter: solids, liquids and gases. Show yourlearners many examples of different kinds of matter and ask them to helpyou sort them into solids, liquids and gases.

Choose an example of a solid, liquid and a gas. Remind your learners thatthe different forms of matter have different properties.

A book

Solids, Liquids and Gases11Key concepts

g Matter exists in 3different forms: solid,liquid and gas.

g Solids, liquids andgases have their owncharacteristics andproperties.

Teacher Task

It is solid

It is brown

I can bend itThe cover is hard

I can fold it

The pages are smoothwhat can isay about a

book?

what can we

say about this

cool drink?

IT CAN

BURN!

We can drink it

We can see through itIt is wet

We can pour the water

It takes the shape of the container

It is runny

A cool drink

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2

Poem about water and its properties

The rain

Swishing, swashing down the lane,

Come the lorries in the rain.

Shunkle, shonkle is the mutter

Of water flowing down the gutter.

Shillop, shallop, through the mud,

Go the cows chewing the cud.

Splashing , splishing, cars go by,

But I’m inside and nice and dry!

ConsolidationRemind your learners that the properties of solids are the things that allsolids have in common. Similarly, the properties of liquids are somethingthat all liquids have in common. The properties of gases are the things thatall gases have in common.

what can we

say about the

air in a

balloon?

We can squash it

It can escape

We can compress it

It makes a sound if we let it outIt takes up all the space

inside the balloon It bouncesIt floats

It presses on the

inside of the balloon

air


3

FFoorrmm ooff mmaatttteerr EEvveerryyddaayy eexxaammpplleess PPrrooppeerrttiieess

SSoolliidd bbooookk,, eerraasseerr,, bbrriicckk,, AAllll ssoolliiddss kkeeeepp tthheeiirr ccuupp,, ttaabbllee,, ppoott,, sshhaappee..cchhaaiirr,, ttiinn,, ppeenncciill

LLiiqquuiidd tteeaa,, wwaatteerr,, mmiillkk,, AAllll lliiqquuiiddss ccaann ppoouurr.. ccooooll ddrriinnkk,, jjuuiiccee,, AAllll lliiqquuiiddss aarree rruunnnnyy.. wwaasshhiinngg--uupp lliiqquuiidd AAllll lliiqquuiiddss ttaakkee tthhee

sshhaappee ooff tthheeiirr ccoonnttaaiinneerr..

GGaass bbuubbbblleess iinn CCooccaa--CCoollaa,, GGaasseess sspprreeaadd oouuttaaiirr,, mmoottoorr ccaarr ffuummeess,, aanndd ffiillll tthhee aavvaaiillaabblleessmmeellll ooff vviinneeggaarr,, ssmmeellll ssppaaccee.. ooff oonniioonn,, ssmmeellll ooff WWhheenn aa ggaass iiss iinn ppeerrffuummee aa ccoonnttaaiinneerr iitt

sspprreeaaddss tthhrroouugghhoouutt tthhee wwhhoollee ccoonnttaaiinneerr..

Write the table on the chalkboard and ask your learners to help you to complete it. Afterwards they can copy the completed table into their books.

SummaryThe properties of solids, liquids and gases


4

Mixing solids and liquids22IntroduceDiscuss with your learners some everyday examples of when we have tomeasure solids and liquids and then mix them together to make some-thing (eg making porridge, vetkoek, bread; mixing cement, gravel, sandand water to make concrete for building; or mixing coffee and water tomake a cup of instant coffee, etc).

Give your learners the opportunity to do the following activity in groups. Make sure that every child in the group participates and gets the chance to measure and mix.

Check that your learners have done some measuring with syringes, medicine spoons and small measuring cylinders. You will find a section on measuring in the Grade 4 Matter & Materials booklet.

Mixing solids and liquids to find out what happens

Mix together Mix together

1 medicine spoon of sand 1 medicine spoon of salt

100ml of water 100ml of water

Draw and label to show what Draw and label to show whathappened happened.

The sand has not dissolved The salt has dissolved in in the water. the water.

We say that the sand is We say that the salt is insoluble in water. soluble in water

Key conceptsg CCeerrttaaiinn ssoolliiddss ddiissssoollvvee

iinn wwaatteerr eegg,, ssaalltt aannddssuuggaarr.. WWee ssaayy tthheeyy aarreessoolluubbllee iinn wwaatteerr..

g SSoommee ssoolliiddss ccaannnnoottddiissssoollvvee iinn wwaatteerr.. WWeessaayy tthheeyy aarree iinnssoolluubbllee..

g WWhheenn wwee mmiixx ssoolliiddssaanndd lliiqquuiiddss::–– IIff tthhee ssoolliidd iiss ssoolluubblleewwee ggeett aa ssppeecciiaallmmiixxttuurree ccaalllleedd aassoolluuttiioonn

Teacher Task

Learner Task

Task card tophotocopy on page

37.100ml

sand

100ml

100ml

100ml

The salt has disappeared


5

Explain SolutionsA Discuss the difference between the two mixtures.

A Refer to the salt and water mixture in which the salt dissolves.

A Introduce the terms “dissolve”, “solute” and “solvent” and “solutions”

A Draw and explain these diagrams on the chalkboard.

MixturesA Refer to the mixture of sand and water.

A Introduce the term “insoluble”.

A Draw and explain these diagrams on the chalkboard.

Teacher Task

HHooww ttoo mmaakkee aa ssoolluuttiioonn

ssaalltt

wwaatteerr ssaalltt--wwaatteerr ssoolluuttiioonn

wwaatteerr

ssaannddssaanndd aanndd wwaatteerr

mmiixxttuurree

WWee ssaayy tthhee ssaalltt hhaass ddiissssoollvveedd.. TThhiiss ssaalltt wwaatteerr iiss nnooww ccaalllleedd aa ssoolluuttiioonn.. IItt iiss aa ssppeecciiaall kkiinndd ooff mmiixxttuurree bbeeccaauussee tthhee ssoolliidd hhaass ddiissssoollvveedd iinn tthhee lliiqquuiidd..

TThhee ssaanndd ccaann ssttiillll bbee sseeeenn iinn tthhee wwaatteerr..WWee ssaayy iitt iiss iinnssoolluubbllee iinn wwaatteerr..TThhiiss ssaanndd aanndd wwaatteerr iiss nnoott aa ssoolluuttiioonn..

HHooww ttoo mmaakkee aa mmiixxttuurree


6

ConsolidationWrite these sentences on the chalkboard and learners can copy them intotheir books.

SSOOLLUUBBLLEE AANNDD IINNSSOOLLUUBBLLEEWWee ssaayy aa ssoolliidd iiss ssoolluubbllee wwhheenn** IItt ddiissaappppeeaarrss wwhheenn mmiixxeedd wwiitthh wwaatteerr..** IItt ddooeess nnoott sseettttllee ttoo tthhee bboottttoomm aafftteerr ssoommeettiimmee..

** IItt ddooeess nnoott sseeppaarraattee ffrroomm tthhee wwaatteerr wwhheennppaasssseedd tthhrroouugghh aa ffiilltteerr..

WWee ssaayy aa ssoolliidd iiss iinnssoolluubbllee wwhheenn** IItt ddooeess nnoott ddiissaappppeeaarr iinn wwaatteerr..** IItt sseettttlleess ttoo tthhee bboottttoomm aafftteerr ssoommee ttiimmee..** IItt sseeppaarraatteess ffrroomm tthhee wwaatteerr wwhheenn ppaasssseeddtthhrroouugghh aa ffiilltteerr..

DISSOLVED

NOT DISSOLVED

Solution

Funnel

Solution

Nothing solidis left in thefilter paper

Solidsare left inthe filterpaper

Mixture

Funnel

Clean liquid (water)

Instant coffee (and filtercoffee) has somesubstances dissolved init which pass throughfilter paper. But instantcoffee also has somesolids which do notdissolve. The solidswhich do not dissolveare caught by the filterpaper.

note to teachers


7

Further discussionStart a discussion about mixtures and solutions. Explain that a solutionis a special kind of mixture because after you have mixed the solid andthe liquid the solid seems to disappear.

Ask your learners:

A Do you think the solid has really disappeared?

A Where did the solid go?

A Do you think the solid is still in the solution? Explain why you sayso?

A What do you think happens to the solid in the solution to make itdisappear?

A Is the water still pure water after the salt has dissolved in it?

Accept a wide range of ideas and explanations from your learners.

Helping children to decide whether a solid hasdissolved or not

When you mix flour and water, or Maizena and water, ormieliemeel and water, it is sometimes difficult to tellwhether the solid has dissolved. This is because thesolid has spread uniformly throughout the mixture.

But if you let the mixture stand for a while (sometimeseven overnight), you will find that the solid settles tothe bottom. This means it is not a solution. The solidhas not dissolved.

In a solution, even if you let it stand for a long time, thesolid will not sink to the bottom - it remains in thesolution. Usually you can see right through a solutioneven if it has changed colour. You can see through itlike coloured glass.

If you are still not sure, you can filter the mixture. If it isa solution, everything will go through the filter paper. Ifit is not a solution, the solid will be caught in the filterpaper and the liquid will go though.

note to teachers


8

Which solids are soluble andwhich solids are insoluble?

33

PreparationProvide the following equipment:

WaterFilter paperFilter funnel Cups or baby food bottlesMedicine spoons

A selection of soluble and insoluble solids to test.(It would be best if the learners can bring some from home.)

Which solids are soluble and which solids are insoluble?1. Bring some solids from home and test them to see if they

are soluble or insoluble in water. 2. Take water and different solids and mix them. Then complete the

table.

3. Draw and write to explain how you can tell whether a solid is soluble.Then draw and write to explain how you can tell when a solid isinsoluble. Use some of the words in the table above to help you.

Key conceptsg Certain solids dissolve

in water eg, salt andsugar. We say they aresoluble in water.

g Some solids cannotdissolve in water. Wesay they are insoluble.

g When we mix solidsand liquids:– If the solid is solublewe get a special mix-ture called a solution

Teacher Task

Mix Does the solid Does the solid Can the solid Is the solid Do we have a 5ml solid + 100ml disappear in settle to the be separated soluble or solution here?water the water? bottom after by the filter insoluble?

some time? paper?

5 ml flour + 100ml No Yes Yes Insoluble Nowater

5 ml Epsom salts Yes No No Soluble Yes+ 100 ml water

5 ml Bicarbonate Yes No No Soluble Yesof soda + 100 ml water

5 ml Maizena + No Yes Yes Insoluble No100 ml water

Learner Task

Task card tophotocopy onpage 38.


9

Solutions Mixtures

What things must you look for to What things must you look for to decide if the solid is soluble in water? decide if the solid is not soluble?

QuestionsDiscuss these questions in your group.1. Why did we use the same amount of solid and water every time?

(So that we can make a fair comparison.)2. Does the amount of solid and water we use make a difference?

(Yes, because if we use a lot of solid and a little water, it won’t dissolve.)

3. What would happen if we kept adding more and more of the solid to thesolution?

(Eventually no more will be able to dissolve.)4. Could we get the solid back again after it has dissolved? How do you

think you could do this?

(Yes, we could boil off the water.)

no, try letting itstand for a while.

can you see through

it?

has this dissolved?i can’t tell. tryshaking it.

We can see through the liquid

No solid on the filter paper

Solid has disappeared

Clear liquid

Solid can be seen

Liquid can be clear or cloudy

Solid on the filter paper

Clear or cloudy liquid


10

Can we make a solid dissolvefaster?

44

PreparationPrepare the learners for the investigation. Explain that they are going toexperiment to find the fastest way to dissolve medicine spoons of solid.They can use any solid that dissolves in water. Explain that everyinvestigation starts with a good question.

DiscussAsk these questions to get your learners thinking about how they will dothe investigation.1. What do you think will make the solid dissolve faster?2. What can you do to the solid to make it dissolve faster?3. What can you do to the water to make the solid dissolve faster?4. What do you think will make the solid dissolve slower? 5. What will we have to measure if we want to find out how long a solid

takes to dissolve? (We will have to measure the time.)

Key conceptsg We can speed up the

time it takes for asolid to dissolve.

g We can speed updissolving by:– heating the solvent– grinding up thesolute into smallpieces–shaking or stirringthe solution.

Teacher Task

do the big lumpsdissolve more slowlythan small lumps?

do different solidsdissolve at different

speeds?will the sugardissolve slowerif i use less

water?

Developing questions for investigationsClass discussion1. Suggest the following question for investigation:

Which will make sugar dissolve faster:A hot water?A tap water?A fridge water?(The learners can use salt or sugar in their investigations.)

2. Ask your learners to add more questions of their own. Try to phrasethem in the same way.


11

The following are two other examples of questions that could beinvestigated.

Which will dissolve faster? A 1 spoons of sugar?A 2 spoons of sugar?A 3 spoons of sugar?

Which will make sugar dissolve faster:A stirring it 10 times?A stirring it 20 times?A stirring it 30 times?

3. Ask learners to suggest some ways that they could go about doingthese investigations

4. Ask each group to choose one of the questions to investigate.You willneed to help them to set up their investigations.

NoteIn an investigation the learners have to:

A Plan an investigation by suggesting things that could beinvestigatedA Carry out an investigation involving a small number of stepsA Report back about what they did and what they found out

On the following page is an example of an assessment task for aninvestigation which works towards these assessment standards.

See the assessmentstandards for LO1,grade 5 on page 63.


12

Assessment Task for LO1Investigation: Can we make a solid dissolve faster?

Investigation: Can we make a solid dissolve faster?Before you start the investigation:

A Choose or help to think up a question to start your investigation.A Discuss how you will set up the investigation. Then do the investigation.

1. Write down the question you are investigating

Question: Which will make sugar dissolve faster:• fridge water?• tap water?• hot water?

2. Draw how you set up the apparatus.3. Record the time it takes for the sugar to dissolve .Do not stir the mixture.4. Record your observations on the recording sheet:

Amount of sugar Amount of water Temperature of Time taken for sugar the water to dissolve

1 spoon 100ml fridge 8 minutes and 50 seconds

1 spoon 100ml tap 6 minutes

1 spoon 100ml hot 3 minutes and 20 seconds

5. Draw a graph of your results.6. Share with another group. Explain to them what you did and what you found out 7. Exchange your results with another group who investigated a different question 8. Draw a graph of their results. Discuss: What did you learn from them?

fridge water tap water hot water1 spoon sugar 1 spoon sugar 1 spoon sugar 100ml water 100ml water 100ml water


Assessment task for LO1 (cont)

There are more examples of investigations on page 42 and 43.

We used the same amount of water and sugar and the bottles were the same size. This ensured that we couldmake a fair comparison between the different water temperatures and how quickly the sugar dissolved.

note to teachers


13

Fridge water Tap water Hot water x

Tim

e(m

inut

es)

y

16

14

12

10

8

6

4

2

0

Graph to show how fast the sugar dissolves in fridge water, hotwater and tap water

Temperature of water

ASSESSMENT CRITERIA

Assessment Task Assessment Criteria

Investigation to find out Planning the investigationif we can make a solid dissolve Learners must be able to:faster A Contribute to thinking up a suitable question for

investigation.A Contribute useful ideas about how to carry out the

investigation.

Conduct the investigationLearners must be able to :A Take regular readings and record these on a suitable tableA The readings must be reasonable and accurate.A Learners must draw a graph to show their results.A The graph must be correctly plotted.A The graph must have a suitable heading, labelled axes

and a suitable scale.

Report on their findingsLearners must be able to :A Explain with confidence what they did and what they

found out.

Assessment task for LO1 (cont)


14

Teacher Task

If this is the first timethat the learners draw agraph, they will need agreat deal of help. Drawa bar graph on thechalkboard and explainhow we draw and labelthe axes. Use a suitablescale and write aheading. Let yourlearners copy this graphinto their books so thatthey can refer to it whenthey draw their own.

note to teachers

What have we learned?DiscussionThis is a useful way to get your learners to share what they have foundout and learned from the investigation.

Ask two learners from each group to move to another group. They needto take their group’s results and the graph that they made to share withthe new group. Then they should explain to the other group what theydid and what they found. Then together they should discuss their results.The questions below should guide them.1. Did your investigation give you an answer to your question?2. Was it the answer you expected?3. Was your investigation accurate? How could you have improved it?4. What does your graph tell you?5. What do the other graphs tell you?

Note to teachers on how to facilitate this

Whilst learners are planningA Help learners to think up some ways to make solids dissolve fasterA Then help them to formulate these ideas into questions. You can

structure the questions in the following ways: If we heat the water will the salt dissolve faster?What will make the salt dissolve faster? Hot water or tap water orfridge water?

Whilst learners are setting up their apparatusA Check that they are measuring the amounts of their solids and

liquids. A Check that they are able to handle the apparatus confidently.A Help them to record the time by using a clock or wristwatch.

Otherwise they can count the seconds by saying: ‘one and two andthree and four’ (four seconds).

Whilst learners are making observationsA Check that the learners have recorded their findings in a suitable

table.A Check that their results are reasonable and accurate.

Helping learners to draw a graphChoose a group with a good set of results. Use these results to showlearners how to make a bar graph of their results. Do this on thechalkboard with the whole class.

How to decide what to put on each axisThe thing that you will observe or measure during the course of theinvestigation will be recorded on the y-axis.

The thing that you made sure will stay the same throughout theinvestigation is what we put on the x-axis.


This is a goodopportunity to helpyour learners use theterms, “morequickly”, “lessquickly”; “biggeramount”, “smalleramount”; etc.

note to teachers

you put the time here on the “y”

(or vertical) axis because that is

what you are trying to find out.

you put the different substances

and amounts that you

chose and set up

on the “x” (or

horizontal) axis.

15

For example:

How to decide what to put in the headingThe heading for the graph depends on what you are recording on each axis.Start the heading with the words, Graph to show …, and then say what youare measuring. You will need to refer to what is on each axis. For example:Graph to show how fast (y axis) sugar dissolves when we use differentamounts of sugar (x axis).

ConsolidationHelp learners to interpret the graphs in a class discussion. This is a veryimportant step. There is no point in drawing a graph if you don’t alsointerpret what the graph is telling you. Learners need help and practise tointerpret graphs. If they make their own, they are more likely to understandthe purpose of graphs and how they work.

Use these questions to help you guide your learners. Write the answers onthe chalkboard.A What effect does heating the liquid have on the dissolving? (When we

increase the temperature of the water, this should speed up dissolving.)A When we increase the amount of solid what effect does it have on the

dissolving? (The more solid we have, the longer it takes to dissolve inthe same amount of water.)

A When we stir the mixture, what effect does it have on the mixture? (Themore you stir the mixture, the more quickly it dissolves.)

SummaryWrite this on the chalkboard so that your learners can copy it into theirbooks.

What do the graphs tell us?What we learnt about dissolvingA We have learnt that a solid dissolves more quickly in hot water.A We have learnt that a bigger amount of solid dissolves more slowly.A We have learnt that a solid dissolves more quickly when we stir the

mixture more times. Etc.


16

Can we get solids back after we55Key concepts

g When a solid isinsoluble we canseparate it from themixture by– letting the solidsettle to the bottomand then decanting(pouring off) thewater, and drying thesolid– filtering (sieving)the mixture so that thesolid stays behind onthe filter paper

g When a solid is solublewe can separate itfrom the solution byallowing the water toevaporate by putting itin a warm place orboiling the solutionuntil all the water hasevaporated.The solidwill crystallize and beleft behind in thecontainer.

Tell your learners a story which will bring out the idea of decanting,sieving and getting substances back out of solutions and mixtures. Try tomake sure that the story is about something which your learners arelikely to be familiar with. For example, straining home-brewed beer, orsieving rice.

ExplainMake a salt solutionIntroduce the idea that when we have dissolved some salt in water, thesolution looks like pure water. But when we drink the solution, we canstill taste the salt. Get your learners to prove this by tasting thesolution. This is because the salt has not disappeared. It has just spreadout in the water.

Explain that we can get the solid back by evaporating the water from thesolution and then we are left with the solid. The water can be evaporatedby boiling it. Another way we can evaporate the water is to spread it outin a shallow container and stand it in a warm place. The process ofgetting the solid back from a solution is called crystallization.

have mixed them with water?

Teacher Task

decanting

sieving

water evaporating


17

PreparationProvide the following apparatus

It is best to demonstratethis with salt. If you usesugar, it often burnsbefore it crystallizes.

note to teachers

Learner Task ACan we get the solid back from a solution?

1. Boil a small amount of salty water until the salt has crystallized.

2. Pour a small amount of salty water in a saucer or lid and place it in a warm dry place.

3. Make a labeled drawing to explain what happened to the salty water.

Use these words to help you: evaporate, crystallize, boil

QuestionsDiscuss these questions in your group. When you boiled the salty water:A What happened to the water? Where did it go?

A What happened to the salt?

A Do you think you could get the water back from a solution?

A How would you do this?


mmaattcchheess


18

Learner Task BHome ProjectLooking for examples of settling, decanting, filtering(sieving), crystallizing and evaporating in our daily lives

1. Look at home to find as many examples as you can of theways we do settling, decanting, filtering (sieving),crystallizing and evaporating in our daily lives.

2. Draw and write about how we make use of decanting,filtering (sieving), crystallizing and evaporating around our homes.

ConsolidationCheck that your learners have found good, correctexamples of these processes from home. Check, too, thatthey show they understand what these concepts mean.If necessary, explain the concepts soluble and insolubleagain to learners. Then explain the new concepts,evaporation, decanting and settling, filtering,crystallizing. These terms will be used again and againin the learning experiences that follow.

Your learners may struggle to findexamples of crystallizing in theirdaily lives. Don’t worry if they areunable to do so. The importantthing is for them to try to findordinary examples of theseprocesses.

note to teachers

hand-made metalstrainer with smallholes.

beer sieve



19

66Key concepts

g WWaatteerr iiss pprreecciioouussbbeeccaauussee iitt iiss ssoo uusseeffuullttoo uuss..

g AAllll lliiffee ddeeppeennddss oonnwwaatteerr..

g WWee uussee iitt ffoorr cclleeaanniinngg,,ddrriinnkkiinngg aanndd ccooookkiinngg..

Water is a precious liquid

Find a story (or ask your learners to bring one), which illustrates theimportance of water. Tell it to your class.

Discuss why it is important to have clean water.Introduce the idea that one of the reasons why water is so useful to us isbecause of its properties.A It is runny. So we can use it to rinse things. For example to wash the

sand off our hands. The runniness of the water washes the insolublesand off our hands.

A It is a good solvent. This means that all sorts of substances aresoluble in water. So we can use it to dissolve some of the dirt andstains out of our clothes. Soaps and washing powders help in thisprocess. We also use it to dissolve things when we prepare food andwhen we cook. For example, making jelly, making tea with sugar,making gravy from meat juices, and so on.

A It flows. So we can use it to carry things in boats. But we also use itto carry away unwanted substances like sewage from our toilets.

ExplainWater is also essential for life. This is because mostof the chemical reactions and life processes whichtake place inside the bodies of plants and animalsdepend on water. For example, photosynthesisdepends on water. In other words, plants make theirown food, using water as one of the ingredients. Aplant also depends on water to transport nutrientsaround its body.

The human body depends on water, which makes upthe major constituent of the blood and cells.

Because we use water in so many ways, it becomespolluted. Then it is difficult to make the waterclean again so that plants and animals can use it.But how does water become polluted? The next taskwill demonstrate how water becomes polluted. Thetask will remind learners that everything that getswashed, poured off, and carried by water eventuallypollutes that same water.

Teacher Task


20

DiscussAsk your learners about the different ways that they use water. Then askthem about the things that they put into water.

Ask:A When you wash with water, what are some of the things that you add

to the water to make washing easier? (Soap, shampoo, bath salts,bubble bath, bath oil, dishwashing liquid, etc.)

A When you clean toilets and floors, what do you add to the water?(Bleach, Handy Andy, antiseptics, Dettol, Jeyes fluid, etc.)

A When you wash your clothes, what do youadd to the water? (Soap, detergent,bleach, fabric softener, etc.)

A When you wash the dishes, what do you add to thewater? (Soap, dish washing liquid, etc.)

A When you cook, what things do you add to the water?(Salt, pepper, spices, herbs, etc.)

Ask your learners to think of all the other thingsthat people use when they wash. For example,when they wash motorcars, motorcar engines,carpets, windows, etc. Try to get learners to thinkof as many different examples as they can.

Remind your learners that anything that we pour onto the ground or intothe soil eventually gets into the water. Farmers also use fertilizers ontheir land. When it rains, this polluted water sometimes runs off into therivers. Sometimes the polluted water sinks into the ground and thenends up in the rivers. Everything we add to water eventually pollutes ourrivers and seas.

Ask your learnersWhat else makes water dirty? (Leaves, grass, papers and plastics, oilpoured into water, sticks, dust, sewage, etc)


21

Learner Task Group work How does water become polluted?1. Look at home and find all the things that you add to water when

you are washing, cleaning and cooking. 2. Bring a small sample of each substance to school.3. Show and tell to your group what you have brought.4. Take a bottle or some container that has a lid. Add clean water to

it.5. Now mix all the things you brought from home into the water.6. Also add some dead leaves and grass and some soil.

DiscussIn your group, discuss these questions.A What does your water look like now?A Would you drink this water or wash with it now?A Which of the things that you added to the water have dissolved?A Which of the things that you added to the water did not dissolve?A When you pour this water down the drain, where will it go?A What will happen to the substances in the water? Where will they

go?A How can we make the water clean again?


Make sure that the

learners keep their

bottles of dirty water for

the next learning

experience when they

will try to make it clean

again.

note to teachers


22

77Key concepts

Making polluted water cleanagain

Hand out pictures of water pollution. Photocopy picture A on pages 54–55.)

Discuss with your learners how water becomes polluted.

Refer to the picture of the polluted river as you ask them the followingquestions. A What are all the things that cause pollution in this river?A Do you think this picture shows all the ways that water can be

polluted?A Is there anything you would add to this picture to show another kind

of pollution?A Does it matter that the water is polluted? (Let learners argue both

sides of this issue)A How does a polluted river affect people, plants and animals?

Refer to the drawing of the river that has been cleaned up. (Photocopy picture B on pages 56–57.)

Ask your learners:A What did the people do to clean up this river?A In what ways did these things help to clean up the river?

Look at the picture of the boys playing on the water near theirhomes in Nyanga on page 23.

Ask your learners,A Do you think these boys are having fun?A What do you think about children playing like this?A Do you think this is a safe place for these boys to play?A Is the water at this place clean?A What are some of the things that could pollute it?A Where do you think that this water comes from?A What will happen if the boys drink this polluted water?A What can the community do to make it safer for the boys to

play here?

Ask your learners to make a play, or a story, or a rap song aboutwhat could happen to the boys who swim here. Tell them to thinkwhat could happen if they drank some of this polluted water. Theyshould also think about what the community could do to makethis a safer place to play – a place with with cleaner water. Intheir play, song or story they must describe the consequences ofhaving contact with polluted water, such as illness. They shouldalso suggest ideas of suitable steps to take to improve theenvironment, for example, moving the toilets further from thewater, cleaning up the litter and disposing of it properly, etc.

Teacher Taskg Water can be polluted

by solid substances(soluble as well asinsoluble).

g Polluted water can bemade clean again bycarrying out purifyingprocesses eg,decanting and settling,filtering, evaporatingand crystallizing.

g Water may containdissolved substancessuch as poisons, whichmake the waterdangerous to drink.

Many rivers in the world are polluted.Can you see what is happening to this river?

What was done to save this river?

A

B


23


24

Learner Task Card AWhat we can do to improve our environment and the waternearby?

Make up a play, or a story, or a rap song aboutwhat happened to the boys who swam in theriver, and how the people cleaned up the river.A What would happen if one of them drank

some of the water?A What did the community do to make this a

safer place to play?A How did the people make the water cleaner?

Discuss different ideas about how to make water clean again when it isdirty. Get your learners to bring out their containers of dirty water.Provide a table full of different equipment eg fabric, cotton-wool, filterpaper and funnels, glass baby-food jars, spirit burners, tripods, gauze,tissues and toilet paper.

Ask your learners to choose anything on the table to make their waterclean again. Then ask your learners to tell you how they made the waterclean. Tell them that they can do this in the form of a report, a storywith pictures, or a rap song.

As they report on what they did (in any language), they should usevocabulary like, ‘pour’ ,‘decant’, ‘strain’, ‘filter’, ‘settle’, etc.

Teacher Task



25

Learner Task Card BMaking polluted water clean again

1. Group task: Use anything on the table to make the waterclean again.

2. Draw and tell a story with pictures, a rap song or a report toshow how you made the water clean.

Questions to discuss:

A Did you manage to make your water clean again?

A Was it completely clean and pure?

A Was it clean enough to drink? Explain why you think so?

Write to explain how you made the water clean.

Today I tried to make dirty water clean.

First I put some cotton wool in a funnel.

Then I put tissues over that.

Next I poured the water through.

Finally the water came out a little bit cleaner.Is your water clean enough to drink? Give a reason for youranswer.

No, the water still looked brown and dirty. Maybe it has germs in it.

Toilet paper

Dirty water

Baby food jarCotton wool

Empty bottle

GauzeFilter paper

Cut-off cooldrink bottle

Funnel



26

ConsolidationLead a discussion about whether the water is now clean enough to drink.(NB Do not let your learners drink this water.) Discuss whether it ispossible to ever get water entirely clean again after it has been polluted.(In fact, it is very difficult and very expensive.)Bring out the following points:A Learners will have managed to remove or filter out only the insoluble

solids from the water.A There may be other substances dissolved in the water, which we

cannot see or remove, such as: salt, chemicals and poisons.A There may also be germs in the water that are harmful. These can be

made less harmful by adding chemicals such as chlorine (eg swimmingpool chemicals or a drop of bleach, or by boiling the water for 15minutes).

A Even after boiling the water there may be poisons left in the water,which were produced by the germs.

A There may also be poisonous chemicals in the water. Many of thesepoisons are not made safe by boiling or bleaching.

Teacher Task


27

Making sewage water clean again88Key concepts

g Sewage is water thatcarries away thewaste from our toiletsand drains.

g People (municipali-ties) have to makesewage water anddrain water cleanagain before it can goback to the river.

g Sewage water iscleaned (or purified) ata sewage treatmentworks where it isallowed to settle andthen it is filtered.

Introduce and explainIntroduce the term “sewage” and explain what it means. Sewage water isthe water that comes from our toilets after we have flushed them. It isalso the water from our drains.

Tell your learners that these days in cities and towns, most of the sewagewater is made clean again so that it can be put back into the river. Thesewage pipes and drainpipes take the dirty water to the sewage farm.This is called a sewage treatment works or a sewage disposal system.There it is purified. The municipality runs the sewage treatment works.

Ask your learners:A Why do you think the water must go back to the river?A Why must the sewage water be made clean again?

Provide your learners with this picture of the sewage works (tophotocopy, see page 49).

Teacher Task

1. Dirty watercomes in andis sieved forthe firsttime.

2. The water passesthrough grit channelsand the solids drop tothe bottom.

3. The solid sludge settleson the bottom.

4. The liquid isfiltered and thegerms aredigested

5. The sludge isdigested bybacteria and usedfor fertiliser

6. The germs are removed from thewater and chemicals are added

7. Clean water goesout to the river

A visit to a sewage works is useful for intermediate phase learners because all the processes are open to viewand with good preparation, children can understand what is happening. Waste from toilets, sinks and bathspasses to the sewers as well as water run-off from streets and waste from factories. All this is taken to the sewage works,

where bacteria play a significant part inits breakdown.

Diagram of a sewage treatment process

SIEVES

GRIT CHANNELS

FILTER TANK

PURIFYING TANK

OUTLET PIPE

SLUDGE TANKS

SLUDGEDIGESTER


28

The sewage treatment processExplain the following processes that happen in a sewage treatment plant 1. Dirty water from storm water drains, household drains and toilets comes into

the sewage treatment plant. Here it is sieved to remove paper, plastic, leavesand rags from it.

2. Then the water is slowly passed through grit channels. Here, any sand or heavyparticles in the water settle to the bottom. The water from the top of the tankstill contains lighter particles of organic matter from the toilets and drains.

3. This water passes into the sludge tanks. In these tanks the water is allowed tostand for a longer time. The organic matter now settles to the bottom. It iscalled sludge and looks like a thick black mud.

4. From the sludge tanks the water passes into the filter tanks. The water still hassome small germs in it even though most of the sludge has already beenremoved. In the filter tanks these germs are filtered out of the water.

5. Meanwhile, the sludge from the sludge tanks is pumped to separate tankscalled sludge digesters. Here the black sludge, which looks like mud, isdigested and broken down by good bacteria. Then it is pumped out and usedfor fertilizer.

6. The water that has been filtered flows into the purifying tanks. The remaininggerms are removed and chemicals are added to kill of any germs that may beleft in the water.

7. The water, which has been treated, is now much cleaner. It is now safe enoughto be piped back into the river.

Talk through the flow chart of sewage treatment works with your learners andidentify the processes. These are:

• Straining / sieving• Settling• Filtering• Digesting (breaking down the germs + solid substances)• Adding chemicals

Preparation1. Ask your learners to build a model of the sewage works. They can do this with

a selection of containers such as yogurt cups, ice cream boxes etc. Toilet rollinsides can be used for the pipes. The learners will have to be able to explainwhat the different purification processes are in their sewage works. They willalso have to show where each process takes place.

2. Arrange the class so that there are six learners in each group. Two learnersmust take responsibility for building the model. Two learners must takeresponsibility for writing the labels and explanations. Two learners must takeresponsibility for the report back and question session.

3. During the report back session, encourage other learners from each group toask questions about the sewage treatment system.

4. Develop the assessment criteria with your learners or adapt the ones on page 29.

Teacher Task


29

Assessment Task for LO2Making sewage water clean againThe purpose of this assessment task is to recall meaningful information. The learners must usethe language that they are fluent in. They must name and describe and explain the featuresand processes of sewage treatment. (See assessment standards for LO2 grade 5 page 64)

1. Build Look at the diagram on page 48. In your group, discuss how you can build a sewagetreatment works using plastic ice cream containers, margarine containers and plastic andcardboard tubes and bottles as shown in the picture. Then build your sewage treatmentworks.

2. WriteMake labels and write an explanation of what is happening to the sewage in each part ofyour model.

3. Report backYou must be able to explain how water would be purified in your model. You must also beable to answer any questions about your model and how water is purified.

QuestionsA Do you think that sewage water which goes back into the river after it has been treated, is

clean enough to drink? Why do you think so?

A Do you think it is expensive to purify water? If so, why do you say so?

Task card tophotocopy onpage 48

ASSESSMENT CRITERIAMaking a model of a disposal system

Assessment task Assessment criteria

Building the modelof a sewage disposalsystem

What we expect from learners

The model must:A Have suitable containers which represent the different tanks.A Have sieves for the water to pass through the ‘pipes’.A The ’tanks’ must be connected in the correct order.A Fit together when connected.A Include any other details which relate to water purification.

Make labels andwrite to explain howthe water is purified

The labels must:A Identify correctly the processes that happen at the different tanks, eg

sieving, settling, filtering, adding chemicals.A Explain how the dirty water is made cleaner during each process.

Report back andanswering questionsabout waterputification

The report back and answers must: A Show understanding of the processes that are used in water purification eg

sieving, settling, filtering, adding chemicals.A Show understanding of the different stages represented by the model.A Contain the correct key words for the different processes.A Must be delivered in a clear and confident way.


30

1

23 4

5 5

6

67

7

432

Model of a water treatment works

1

2

3

45

6 7

Model of a water treatment works

SIEVES1 Dirty water comes in and

is sieved for the first time.

GRIT CHANNELS2 The water passes through grit

channels and the solids drop to the bottom (ice cream boxes)

SLUDGE TANKS3 The sludge settles on the

bottom (bottles).

FILTER TANKS4 The liquid is filtered and

the germs are digested.

SLUDGE DIGESTER5 The sludge is digested

(yoghurt cups).

PURIFYING TANKS6 The germs are removed

and chemicals are added.

OUTLET PIPE7 Clean water goes out to the

river (pipe at the very end).


31

IntroductionLong ago, how do you think people made sure that their water was cleanenough to drink?

PreparationPrepare for your learners to find out the following:

• How people long ago found water and kept it clean.• How people in rural areas make sure that their water is clean.• What can happen if you drink or swim in water that isn’t clean.

1. Tell your learners to try to find out at home how people in the pastensured that they had clean water. Afterwards, facilitate a classdiscussion about what they found out. Listen carefully for points yourlearners make which provide relevant information about the processespeople have used to make water clean.

2. Read Sweet Water /Amanzi Mnandi page 51.3. Ask learners to draw or find pictures that illustrate some of the points

they discussed and read about.4. Find a space on the classroom wall and put up flashcards of the task

card questions on the wall (see page 50). Make sure there is enoughspace for the children to place their pieces of work under the variousheadings. Alternatively, if learners have enough information they canmake group posters, which you can display on the walls.

How do we get clean drinking water?99Key concepts

g LLoonngg aaggoo ppeeooppllee hhaadd ttooffeettcchh tthheeiirr oowwnn wwaatteerr..

g PPeeooppllee hhaadd wwaayyss ttooddeecciiddee wwhheetthheerr tthheeiirrwwaatteerr wwaass cclleeaanneennoouugghh ttoo ddrriinnkk..

g TThheeyy hhaadd ssppeecciiaall wwaayyssooff ttrraannssppoorrttiinngg aannddssttoorriinngg tthheeiirr wwaatteerr ssootthhaatt iitt wwoouulldd rreemmaaiinncclleeaann..

river

Teacher Task


32

Assessment Task for LO3

Find out how today, and long ago, people made sure their water was cleanThe purpose of this learning experience is to help learners understand science andtechnology in the context of history and indigenous knowledge. (See assessment standards for LO3 Grade 5 page 66)

1. Ask and Find Out

Find out from someone at home:

A Long ago, how did people find water and keep it clean? How is this done today?

A In the past, how did people in rural areas make sure that their water was clean? How is this done today?

A How did they make sure it was clean enough to drink? How do people do this today?

A What can happen if you drink or swim in water that isn’t clean?

A Which is better? The old way or the new way? (You can choose either way, but you must be able to give reasons for your choice.)

2. Report back in a class discussion

3. Contribute to a class display.

Write and draw what you found out at home.



33

ConsolidationDiscuss with your learnersA Why is it important to have fresh clean water?

A How do we know if our water is clean?

A What happens when people don’t have fresh clean water?

A Why do some people have access to clean water but other people

don’t?

A What can our communities do to make sure we have fresh water?

Suggested writing frame

Today and long ago people made sure their water was cleanThey collected it in a clean placeLong ago . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Today . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

They carried it in clean containersLong ago . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Today . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

They stored it carefully and kept it clean.Long ago . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Today . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Sometimes they had to make it clean by:Long ago . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Today . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

If you drink dirty water . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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

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

ASSESSMENT CRITERIA

Assessment task Assessment criteria

Find out how people made sure that their Learners must:water was clean long ago. A Contribute relevant information about long agoFind out how people make sure that their methods of keeping water clean.water is clean today. A Understand how the long ago methods worked

for keeping water clean.A Be able to make comparisons between today’s

methods and long ago methods.


34

PERI

OD 1

1.So

lids,

liq

uids

and

gas

es•

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her i

ntro

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s th

e th

ree

stat

es o

f mat

ter

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rite

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e pr

oper

ties

of s

olid

s, li

quid

san

d ga

ses

PERI

OD 2

2. M

ixin

g so

lids

and

liqui

ds•

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her i

ntro

duce

s ev

ery d

ayex

ampl

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ners

mak

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es w

ithdi

ffere

nt s

olid

s an

d wa

ter

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ache

r con

solid

atio

n an

dex

plan

atio

ns

PERI

OD 3

3. W

hich

sol

ids

are

solu

ble

and

whi

ch s

olid

s ar

ein

solu

ble?

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arne

rs te

st v

ario

ussu

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nces

for s

olub

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arne

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raw

and

write

expl

anat

ions

(Sta

rt ge

tting

lear

ners

to c

olle

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ms

for b

uild

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for

lear

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exp

erie

nce

8)

PERI

OD 4

3. C

ontd

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ners

fini

sh e

xpla

natio

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s qu

estio

ns4.

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esti

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on:

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we

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?•

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fin

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to le

arne

rs

PERI

OD 5

4. C

ontd

. •

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ts le

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deve

lop

ques

tions

for

inve

stig

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LO1

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or

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arn

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ex

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PERI

OD 6

4. C

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LO1

cont

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ners

fini

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the

plan

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egin

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inve

stig

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PERI

OD 7

4. C

ontd

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t ta

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LO1

cont

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con

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with

the

inve

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ses

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lear

ners

how

to d

raw

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PERI

OD 8

4. C

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LO1

cont

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m g

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togr

oup

and

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e re

sults

PERI

OD 9

4. C

ontd

. •

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her c

onso

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arni

ngs

from

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inve

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ou w

ill h

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to s

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time

to g

ive

lear

ners

feed

back

afte

r you

hav

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sess

ed th

ein

vest

igat

ions

PERI

OD10

5. C

an w

e ge

t th

e so

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back

aft

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PERI

OD 1

16.

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e di

ffere

ntus

es o

f wat

er a

nd w

hat w

e ad

dto

wat

er•

Lear

ners

pre

pare

to b

ring

sam

ples

from

hom

ePE

RIOD

12

6. c

ontd

. •

Lear

ners

add

thei

r pol

luta

nts

towa

ter

•Le

arne

rs’ g

roup

dis

cuss

ion

abou

t the

dirt

y wat

er

PERI

OD 1

37.

Mak

ing

dirt

y w

ater

cle

anag

ain.

•Cl

ass

disc

ussi

on a

bout

apo

llute

d riv

er u

sing

pic

ture

s•

Disc

ussi

on a

bout

boy

ssw

imm

ing

in p

ollu

ted

wate

r•

Lear

ners

sta

rt to

dev

elop

a p

lay

or ra

p or

son

g ab

out h

ow th

eco

mm

unity

can

impr

ove

the

wate

r qua

lity

PERI

OD 1

47.

Con

td.

•Le

arne

rs c

ompl

ete

thei

r pla

ysan

d so

ngs

•Le

arne

rs p

erfo

rm th

eir s

ongs

and

play

s

PERI

OD 1

57.

Con

td.

•Le

arne

rs p

erfo

rm th

eir s

ongs

and

play

s


35

PERI

OD 1

67.

Con

td.

•Le

arne

rs m

ake

thei

r dirt

y wat

ercl

ean

•Te

ache

r set

s up

equ

ipm

ent t

opu

rify w

ater

.

PERI

OD 1

77.

Con

td.

•Le

arne

rs re

flect

on

the

proc

ess

of m

akin

g wa

ter c

lean

•Le

arne

rs w

rite

a re

port

on th

eir

met

hod

•Te

ache

r con

solid

atio

n

PERI

OD 1

88.

Mak

ing

sew

age

wat

ercl

ean

agai

n.•

Teac

her i

ntro

duce

s an

dex

plai

ns th

e te

rm ‘s

ewag

e’•

Teac

her e

xpla

ins

the

proc

ess

ofse

wage

trea

tmen

t usi

ng p

ictu

re•

Teac

her p

repa

res

lear

ners

for

asse

ssm

ent t

ask

PERI

OD 1

9 8.

Con

td.

•Te

ache

r exp

lain

s th

at le

arne

rswi

ll bu

ild a

mod

el o

f a s

ewag

etre

atm

ent w

orks

, usi

ng th

epi

ctur

e as

a g

uide

Asse

ssm

ent

task

LO2

•Te

ache

r exp

lain

s th

e ta

sk a

ndas

sess

men

t crit

eria

PERI

OD 2

08.

Con

td.

Asse

ssm

ent

task

LO2

con

td.

Lear

ners

beg

in to

bui

ld th

eir

mod

el

PERI

OD 2

18.

Con

td.

Asse

ssm

ent

task

LO2

con

td.

•Le

arne

rs c

ontin

ue to

bui

ld th

eir

mod

els

•Le

arne

rs p

repa

re th

eir l

abel

sex

plan

atio

ns a

nd re

port

back

PERI

OD 2

28.

Con

td.

Asse

ssm

ent

task

LO2

con

td.

•Le

arne

rs p

rese

nt th

eir m

odel

san

d re

port

back

PERI

OD 2

38.

Con

td.

Asse

ssm

ent

task

LO2

con

td.

•Le

arne

rs p

rese

nt th

eir m

odel

san

d re

port

back

Note

: you

will

hav

e to

sch

edul

etim

e to

giv

e le

arne

rs fe

edba

ckaf

ter y

ou h

ave

asse

ssed

the

mod

els

and

repo

rt ba

cks

PERI

OD 2

49.

How

do

we

get

clea

ndr

inki

ng w

ater

?•

Teac

her i

ntro

duce

s id

ea th

atpe

ople

thro

ugh

the

ages

mad

esu

re th

at th

eir w

ater

was

cle

an•

Prep

are

lear

ners

to fi

nd o

ut b

yas

king

at h

ome,

usi

ng s

ome

ques

tions

PERI

OD 2

59.

Con

td.

•Te

ache

r pre

pare

s le

arne

rs fo

ras

sess

men

t tas

kAs

sess

men

t ta

sk L

O3.

•Te

ache

r exp

lain

s th

e ta

sk a

ndas

sess

men

t crit

eria

PERI

OD 2

69.

Con

td.

Asse

ssm

ent

task

LO3

.Co

ntd.

•Le

arne

rs s

hare

thei

rin

form

atio

n in

a c

lass

disc

ussi

on•

Lear

ners

dra

w an

d wr

itein

form

atio

n wh

ich

will

prod

uce

a cl

ass

post

er

PERI

OD 2

79.

Con

td.

Asse

ssm

ent

task

LO3

.Co

ntd.

•Le

arne

rs a

dd th

eir i

nfor

mat

ion

to th

e cl

ass

post

erNo

te: y

ou w

ill h

ave

to s

ched

ule

time

to g

ive

lear

ners

feed

back

afte

r you

hav

e as

sess

ed th

eir

cont

ribut

ions

to th

e po

ster

PERI

OD 2

89.

Con

td.

•Te

ache

r con

solid

atio

n

This

wor

k sc

hedu

le is

onl

y a s

ugge

stio

n. It

ass

umes

less

ons

that

last

for

50- 6

0 m

inut

es. Y

ou w

ill h

ave

to a

dapt

it a

ccor

ding

to yo

ur c

ircum

stan

ces.


36

Teacher ResourcesTask Cards to photocopy

1. Task card 1. Mixing solids and liquids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

2. Task card 2. Which solids are soluble, and which solids are insoluble in water? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

3. Task card 3. Assessment Task for LO1 Investigation: can we make a solid dissolve faster . . . . . . . . . . . . . . . . . . . 39

4. More examples of investigations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41–43

5. Task card 4 A. Can we get the solid back from a solution? . . . . . . . . . . . 44

Task card 4 B. Home Project . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

6. Task card 5 How does water become polluted? . . . . . . . . . . . . . . . . . . . . . 45

7. Task card 6 A. What we can do to improve our environment and the water nearby? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

Task card 6 B. Making polluted water clean again . . . . . . . . . . . . . . . . . . . 47

8 Task card 7. Assesment Task for LO2Making sewage water clean again . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

Picture of sewage treatment process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

9 Task card 8. Assessment Task for LO3 How did people today and long ago make sure that their water was clean? . . . . . . . . . . . . . . . . . 50

10. Sweet water/Amanzi Amnandi . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51–53

11. Pictures and diagrams to photocopy . . . . . . . . . . . . . . . . . . . . . . . . . . . 54–57

• Water pollution

• Cleaning rivers

Section 2


37

LEARNER TASK CARD 1 TASK CARDS TO PHOTOCOPY

Mixing solids and liquids to find out what happens

Mix together Mix together

1 medicine spoon of sand 1 medicine spoon of salt

100ml of water 100ml of water

Draw and label to show what happened Draw and label to show what happened.

The sand has not dissolved in the water. The salt has dissolved in the water.

We say that the sand is ———————— We say that the salt is ————————

———————————————————— ————————————————————

Mixing solids and liquids

100ml100ml


38


A. Bring some solids from home and test them to see if they are soluble or insolublein water.

B. Take water and different solids and mix them. Then complete the table.

C. Draw and write to explain how you can tell whether a solid is soluble. Then drawand write to explain how you can tell when a solid is insoluble. Use some of thewords in the table above to help you.A What things must you look for to decide if the solid is soluble in water?A What things must you look for to decide if the solid is not soluble?

D. Questions

Discuss these questions in your group.

1. Why did we use the same amount of solid and water every time?

2. Does the amount of solid and water we use make a difference?

3. What would happen if we kept adding more and more of the solid to the solution?

4. Could we get the solid back again after it has dissolved?

Which solids are soluble and which solids are insolublein water?

Mix Does the solid Does the solid Can the solid Is the solid Do we have a 5ml Solid + 100ml disappear in settle to the be separated soluble or solution here?water the water? bottom after by the filter insoluble?

some time? paper?

5 ml Flour + 100mlwater

5 ml Epsom salts+ 100 ml water

5 ml Bicarbonate of soda + 100 ml water

5 ml Maizena + 100 ml water


39

The purpose of this assessment task is to:

A Plan an investigation by suggesting things that could be investigated

A Carry out an investigation involving a small number of steps

A Report back about what you did and what you found out

(See the assessment standards for LO1, grade 5 page 63)

Investigation: Can we make a solid dissolve faster?Before you start the investigation:

A Choose or help to think up a question to start your investigation.

A Discuss how you will set up the investigation. Then do the investigation.

1. Write down the question you are investigating.

Question: Which will make sugar dissolve faster:

A Fridge water? A Tap water? A Hot water?

2. Draw and label how you set up the apparatus.


Learner task card 3 Assessment Task for LO1


40

LEARNER TASK CARD 3 (CONT) TASK CARDS TO PHOTOCOPY

3. Record the time it takes for the sugar to dissolve. Do not stir the mixture.

4. Record your observations on the recording sheet:

5. Draw a graph of your results (remember to write a heading and label the axes).

6. Share with another group. Explain to them what you did and what you found out.

7. Exchange your results with another group who investigated a different question.

8. Draw a graph of their results. Discuss: What did you learn from them?

Amount of sugar Amount of water Temperature of the water Time taken for sugar to dissolve


41

Examples of Investigations

EXAMPLE 1

Question: Which will dissolve faster:

A 1 spoons of sugar?



1. Set up the investigation like this:

2. Do not stir the mixture.

3. Record the time it takes for the sugar to dissolve.

4. Example of the recording sheet:

Amount of sugar Amount of water Time taken for sugar to dissolve

1 spoon sugar 2 spoons sugar 3 spoons sugar 100ml tap water 100ml tap water 100ml tap water


42

5. Example of the graph

Note: We used the same amount of tap water and the bottles were the same size. Thisensured that we could make a fair comparison between the different amounts of sugarand how quickly it dissolved.

EXAMPLE 2

Question:

Which will make sugar dissolve faster:A stirring it 10 times?A stirring it 20 times ?A stirring it 30 times?

1. Set up the investigation like this:

EXAMPLES OF INVESTIGATION TASK CARDS TO PHOTOCOPY

2 spoons 4 spoons 6 spoons x

Tim

e(i

nm

inut

es)

y

16

14

12

10

8

6

4

2

0

Graph to show the time it takes to dissolve 1 spoon,2 spoons and 3 spoons of sugar

10 stirs 20 stirs 30 stirs1 spoon sugar 1 spoon sugar 1 spoon sugar 100ml tap water 100ml tap water 100ml tap water


43

1. Record the time it takes for the sugar to dissolve

2. Example of the recording sheet:

Amount of sugar Amount of water Number of times Time taken for sugar to we stirred dissolve

3. Example of the graph

Number of stirs

Note: We used the same amount of tap water and sugar and the bottles were thesame size. This ensured that we could make a fair comparison between the numberof times we stirred and how quickly the sugar dissolved.

EXAMPLES OF INVESTIGATION TASK CARDS TO PHOTOCOPY

10 stirs 20 stirs 30 stirs x

Tim

e(i

nm

inut

es)

y

4

3™

3

2™

2

1™

1

™0

Graph to show the time it takes for the sugar todissolve when we stir the solution.


44


A Can we get the solid back from a solution?1. Boil a small amount of salty water until the salt has crystallised.

2. Pour a small amount of salty water in a saucer or lid and place it in a warm dry place.

3. Make a labeled drawing to explain what happened to the salty water.

Use these words to help you: evaporate, crystallize, boil

QuestionsDiscuss these questions in your group.

When you boiled the salty water:

A What happened to the water? Where did it go?

A What happened to the salt?

A Do you think you could get the water back from a solution?

A How would you do this?

B Home ProjectLooking for examples of settling, decanting, filtering (sieving), crystallizingand evaporating in our daily lives

1. Look at home to find examples of the ways we do settling, decanting,filtering (sieving), crystallizing and evaporating in our daily lives.

2. Draw and write about how we make use of decanting, filtering (sieving),crystallising and evaporating around our homes.

3. Discuss: Did you find examples of all the processes at home? Which oneswere difficult to find? Why?

Can we get the solids back after mixing themwith water?


45


Group work1. Look at home and find all the things that you add to

water when you are washing, cleaning and cooking.

2. Bring a small sample of each substance to school.

3. Show and tell to your group what you have brought.

4. Take a bottle or some container that has a lid. Add clean water to it.

5. Now mix all the things you brought from home into the water.

6. Also add some dead leaves and grass and some soil.

DiscussIn your group, discuss these questions.

A What does your water look like now?

A Would you drink this water or wash in it now?

A Which of the things that you added to the water have dissolved?

A Which of the things that you added to the water did not dissolve?

A When you pour this water down the drain, where will it go?

A What will happen to the substances in the water? Where will they go?

A How can we make the water clean again?

How does water become polluted?


46


A. Improving the environment

A What we can do to improve our environment and the water nearby?

Make up a play, or a story, or a rap song about what happened to the boys who swam in the river and how the people cleaned up the river.

A What would happen if one of them drank some of the water?

A What did the community do to make this a safer place to play?

A What did the people do to make the water cleaner?


47


B. Making polluted water clean again

Toilet paper

Dirty water

Baby food jarCotton wool

Empty bottle

GauzeFilter paper

Cut-off cooldrink bottle

Funnel

1. Group task

A Use anything on the table to make the water clean again.

2. Draw and tell a story with pictures, a rap song or a report to show how youmade the water clean.

3. Questions to discuss

A Did you manage to make your water clean again?

A Was it completely clean and pure?

A Was it clean enough to drink? Explain why you think so?

3. Write to explain how you made the water clean.

Today . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

First . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Then . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Next . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Finally . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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

5. Is your water clean enough to drink? Give a reason for your answer.

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

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

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

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


48

1

23 4

5 5

6

67

7

432


Making sewage water clean againThe purpose of this assessment task is to recall meaningful information. Thelearners must use the language that they are fluent in. They must name and describeand explain the features and processes of sewage treatment. (See assessmentstandards for LO2 grade 5, page 64)

1. Build

Look at the diagram below. In your group, discuss how you can build a sewagetreatment works using plastic ice cream containers, margarine containers andplastic and cardboard tubes and bottles as shown in the picture. Then build yoursewage treatment works.

2. Write

Make labels and write an explanation of what is happening to the sewage in eachpart of your model.

3. Report back

You must be able to explain how water would be purified in your model. You mustalso be able answer any questions about your model and how water is purified.

Questions

A Do you think that sewage water which goes back into the river after it has beentreated, is clean enough to drink? Why do you think so?

A Do you think it is expensive to purify water? if so, why?

Assessment Task for LO2


49

1.Di

rty

wat

erco

mes

in

and

is s

ieve

d fo

rth

e fi

rst

tim

e.

2. T

he w

ater

pas

ses

thro

ugh

grit

cha

nnel

san

d th

e so

lids

drop

to t

he b

otto

m.

3. T

he s

olid

slu

dge

sett

les

on t

hebo

ttom

.

4. T

he l

iqui

d is

filt

ered

and

the

germ

s ar

e di

gest

ed

5.Th

e sl

udge

is

dige

sted

by b

acte

ria

and

used

for

fert

ilise

r

6.Th

e ge

rms

are

rem

oved

fro

m t

hew

ater

and

che

mic

als

are

adde

d

7.Cl

ean

wat

er g

oes

out

to t

he r

iver

SIEV

ES

GRIT

CHAN

NEL

S

FILT

ERTA

NK

PURI

FYIN

GTA

NK

OUTL

ETPI

PE

SLU

DGE

TAN

KS

DIGE

STER


50


Find out how today, and long ago, people made sure theirwater was clean

The purpose of this assessment task is to help learners understand scienceand technology in the context of history and indigenous knowledge. (See page66 for assessment standards for LO3 Grade 5)

1. Ask and Find Out

Find out from someone at home, or read “Sweet water/ Amanzi Amnandi”on page 51

A Long ago, how did people find water and keep it clean? How is this donetoday?

A In the past, how did people in rural areas make sure that their water wasclean? How is this done today?

A How did they make sure it was clean enough to drink? How do people do thistoday?

A What can happen if you drink or swim in water that isn’t clean?

A Which is better? The old way or the new way? (You can choose either way, but you must be able to give reasons for your choice.)

2. Report back in a class discussion.

3. Contribute to a class display by writing and drawing about what you found out at home.

Learner Assessment task for LO3


51

Sweet Water and early Nguni people

The early peoples of southern Africa hadcommonsense ways of collecting andstoring “sweet” water, not unlike early

humans in other parts of the world. Thispassage looks at Nguni water collectionpractices. (Comments and scientificobservations are in brackets so that readersmight see the practical wisdom behind somewater collection myths and techniques of thepast.)

Before the time of the Zulu King Shaka,sweet water was called “ amanzi amnandi”.Shaka’s mother was called Nandi and it is saidthat because it was not considered respectfulto use the queen mother’s name in this way,Shaka referred to sweet water as “amanziamtoti”. (This is how the town of Amanzimtotisouth of Durban got its name.)

Today both terms are usedand many people of Nguniorigin will sniff, smile and holdup “sweet” water collectedfrom a river, spring or well fortheir household needs. (Waterquality scientists today stillhave people smell and tastehousehold water. Human senses give a refined indication of whetherwater is good and clean and fresh.)

Amanzi Amnandi nabantu basendulo

Abantu basendulo babenezindlela zaboezithile ababezisebenzisa uma bekhaamanzi emfuleni. Izindlela

zazehlukahlukana ngokwezizwe.Amanzi okuphuza nawokupheka ayebizwa

ngokuthi amanzi amnandi. Ngokwesikolokuhloniphisa kwathi ngesikhathi seNkosiuShaka, amanzi amnandi abizwa ngamanziamtoti, kuhlonishwa unina wenkosi, uNandi.

Emandulo amanzi ayekhiwa ezindawenilapho abantu babewezwa khona amanzi ekhalanasematsheni. Babewakha esiphethwini laphoayehlanzekile khona emahle. Izingubazaziwashwa emfuleni nezinkomo futhizaziphuza khona.

Lapho kwakukhiwa khona amanzikwakuphenduka kube indawo lapho

kuhlanganela khona izintombinezinsizwa. Izinsizwa zazilindaosebeni lomfula zihuba ingomazidlalisela ezintombini umazizokha amanzi. Izintombizaziza emfuleni zishayakancane zihubela phansisezinanela ukuhashwayizinsizwa. Kwakujabulisaukukha amanzi ngoba babaziukuthi kwakungenzeka baficeizinsizwa ezizokweshela.

Ngalesikhathi kuhlangenwe lapho

Sweet Water / Amanzi Amnandi


52

Historically water was usually collected inareas where people could hear it running overstones or dripping down rocks. (Welloxygenated water supports natural biologicalcleansing processes.) If a spring was forhuman use, it was protected by a circle ofrocks with a small outlet. Cattle drankelsewhere.

An area nearby was cleared and the sitesoon became a meeting place for youngpeople. Young men would hang around thesewater collection sites, playing musicalinstruments and admiring the maidens whocame to collect water. The girls would saunteralong slowly and gracefully, singing andflirting. Water collecting was rarely seen as atiring or boring chore because of the prospectof courtship!

Protecting the source of waterA water source would always be approached

with care so as not to frighten crabs andother small water animals. When disturbed,their movement would stir up sediments andthe collector would have to wait for the silt tosettle. The surface film was brushed aside for“ sweet water” to be collected. (Sediments andsurface films have higher bacteria numbersthan the middle waters of pools and rivers.Today scientists take water samples below thesurface film taking care not to suck upsediments. In this wayscientists can getconsistent and reliablemeasures of bacterialcontamination.)

Collecting water andkeeping it clean

Clay pots were filledwith water and covered with a collectingbowl, a piece of skin or a mat made fromincema (juncus kraussi) grass. The waterwould thus stay cool and fresh. (Waterevaporating through the sides of a porous claypot cooled the contents. Most water bacteriacannot reproduce in cool, dark conditions.Some micro-organisms envelop themselves incalcium secretion in the pores of clay pots.Scientists spoken to were uncertain about detailof these issues but it is of note that, in earliertimes, great care was taken to scour out acalcium – like scale in water pots. Also of note

babeqiniseka kakhulu ukuthi abazibangeliumsindo izilwanyana zasemanzini, hlezezethuke ziyaluze kudungeke amanzi. Umaamanzi esedungekile kwakufanele ukuthi lowoozokha awalinde isikhashana ukuze acwebe.Ngaphaqmbi kokuthi umuntu awakhe amanziayephebezwa ngogqoko ukuze akhe amanziamahle.

Amanzi ayekhiwa agcwaliswe izimbizaambozwe ngogqoko. Ayethi uma ebekwelapho agcineke emnandi futhi ebanda.

Ayemaningi amasiko ayegcinwa nezinkoleloezazibakhona mayelana namanzi.Kwakunenkolelo yokuthi uma umuntuechamela emanzini noma ebhukudauzoshintsha ubulili bakhe. Izinganezazixwayiswa kakhulu ngalokhu.

Abantu babengokholelwa ukuthi laphokukhona amaxoxo amanzi akhona angabamnandi. Amaxoxo ayedliwa uthekwane.Kwakusabisa ukukha amanzi ubukwauthekwane kanti futhi kwakungafanele ukuthiuwubulale ngoba kwakuthiwa uma ubulalauthekwane noma untshontsha iqanda lawoumuzi wakini uzosha

Amanzi babengawakhi uma izulu linethilengoba amanzi ayedungekile abanyebabedlulisa izinsuku ezine ngaphambikokukha amanzi emva kwezimvula ukuzebawathole esecwebile. Kukhona izitshaezazibekwa uma kunetha izulu kukhongozelwaamanzi, ayephuzwa noma kuphekwe ngawongoba ayeba mahle.

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is that when the grass ‘lids’ and head rings forcarrying pots became old they were simplythrown away and new ones were woven.Discarded lids did not pollute the river liketoday’s bottle tops and plastic waste.)

There were many others customs adtraditionalpracticessurroundingwater. Childrenwere warned thaturinating in ariver wouldchange them tothe opposite sex! (This mythwas probably sufficiently frightening to preventpeople urinating in streams. This would havelimited a disease like bilharazia. The bilharziaparasite is passed on from human urine andfeaces to small water snails. From these its lifecycle takes the diseases back to people throughriver water.)

Traditional myths and warningsNguni water collectors say that where there

are frogs one does not find sweet water. Frogsare eaten by hammerkops (uthekwane, ‘thelightning bird’) and the prospects of collectingwater while being watched by a ‘witch-bird’must have been terrifying in earlier timeswhen spirits, myth and mystery had a more

central place in everyday social life. Childrenwere told that if they killed this bird or stoleits eggs their homes would go up in flames.(Where there are frogs one will usually findsnakes. Both animals are feared by manypeople today, not least children told Ngunimyths of witches and lightning to fill the heartwith terror. Today, scientific tests suggest thatmany frog species need ‘sweet water’ if they areto live and reproduce successfully. There mustbe some doubt about the Nguni suggestion thatfrogs are an indication of water that is not fitfor human consumption.)

It was also said that it was not advisable tocollect water from a river after heavy rain atthe start of annual rainy season. Indigenouscommonsense told people to put out to collectrain-water. River water would again becollected four days after the rains stopped andthe water had cleared. (Heavy rains washhuman and animal wastes into rivers. There isthus a rapid increase in faecal bacteria anddisease. In KwaZulu-Natal health workers haveto warn rural people not to collect river waterafter heavy rains as few remember an earlierNguni practice of not collecting rain-water forfour days.)

Learning about historical water collectionand storage practices can develop a respect forearly people and might also help ourunderstanding of water quality issues.

thanks to share-net for the use of this materialtel 033-3303931


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Extracts from the National Curriculum Statement for Natural Sciences Grades R-91. Core knowledge and concepts for Matter and Materials (NCS) . . . . . . . .60–61

2. Outcomes and assessment standards (NCS) . . . . . . . . . . . . . . . . . . . . . . . .62–67

Section 3


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Revised National Curriculum Statements Grades R–9 (Schools)

Matter and Materials

The paragraphs below have been extracted from the NCS policydocuments. We have numbered each paragraph and supplied aheading for each paragraph. This makes the paragraphs easier to workwith.The paragraphs describe the knowledge and concepts the learnersmust know.

Properties and Uses of MaterialsStructure, Reactions andChanges of Materials

Unifying statement: We can classify materials by theirproperties, in order to establish types and patterns.Properties determine the selection of materials forparticular uses.

Unifying statement: We can modify materials inways we choose, through our understanding of theirsub-structure.

Foundation Phase

1. Sorting materials according to their differentpropertiesMaterials have different properties such as texture,colour, strength and heaviness, and can be classified bythese properties. We make things with materials whichhave the properties we want.

2. Mixing different substancesSubstances can be mixed and sometimes changescan be seen, such as the dissolving of a solid, or newcolours when food colourings/paints are mixed.

Intermediate Phase

1. Boiling and melting points of different substancesPure substances have melting temperatures and boilingtemperatures which are characteristic for eachsubstance, and help us to identify the substance.

2. Materials, their properties and classifying themMaterials are evaluated and classified by theirproperties (such as hardness, flexibility, thermalconductivity or insulation, electrical conductivity orinsulation whether they can be magnetised, solubilityand rusting).

3. Metals, ceramics, polymers and compositematerialsMajor classes of materials are metals, ceramics(including glasses) and polymers (including plastics andfibres). Composite materials combine the properties oftwo or more materials.

4. Temporary and permanent changes to materialsSome changes to materials are temporary but otherchanges are permanent.

5. Changes brought about by heatingSubstances change when they receive or lose energyas heat. These changes include contraction andexpansion, melting, evaporation, condensation andsolidification. (Links with Energy and Change)

6. Dissolving-factors that affect the speed ofdissolvingThe dissolving of a substance in a solvent dependson variables which affect the rate of dissolving.

CORE KNOWLEDGE AND CONCEPTS IN MATTER AND MATERIALS


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Properties and Uses of MaterialsStructure, Reactions andChanges of Materials

Senior Phase

1. Different states of matter and their propertiesSubstances in different states (‘phases’) have distinct propertiessuch as crystalline structures, or compressibility/incompressibility,or tendency to diffuse.

2. Absorption and radiation by different surfacesDark-coloured surfaces get hotter than light-coloured surfaceswhen exposed to radiating sources of energy like the Sun. Dark-coloured objects radiate their energy as heat more readily thanshiny light-coloured objects. (Links with Energy and Change)

3. Magnetism and electrical chargingSome materials are magnetised by electric currents or magnets.Some materials can be electrically changed by rubbing them with adifferent material. (Links with Energy and Change)

4. Conductors and resistorsSome conductors and circuit components reduce the current in anelectric circuit to a significant extent and are called resistors.Resistors can be selected or designed to control currents.

5. Separating and purifying mixturesA pure substance cannot be separated into different substanceswhile a mixture can be separated usually by physical means.Differences in properties can be used to separate mixtures ofdifferent substances (by methods such as filtration, distillation,evaporation, chromatography or magnetism). (Links with Matterand Materials)

6. Oxygen, carbon dioxide and hydrogen – properties reactionsand commercial usesSpecific gases may be separated from the air or produced inreactions, and have many uses in industry and other sectors of theeconomy. Oxygen, hydrogen and carbon dioxide have characteristicproperties and reactions by which we can identify them.

7. Extraction of raw materialsExtracting useful materials from raw materials depends onchemical reactions and methods of separation.

8. Processing and producing raw materials – effect on theenvironmentRaw materials, from which processed materials are made, must bemined, grown or imported from other countries. Raw materials thatare mined are non-renewable and mining has environmental costs.Growing raw materials involves choices about the use of arableland and water catchment areas

9. Particle model of matterA particle model of matter can explainphysical changes of substances such asmelting, evaporation, condensation,solidification, diffusion and heating byconduction.

10. Acids and bases, reaction of acidsMany household substances are acidic orbasic. Indicators are substances that reactwith acids and soluble bases to produceproducts that have distinctive colours. Acidsand bases neutralise one another to formsalts. Acids have characteristic reactions withmetals, metal oxides, hydroxides andcarbonates.

11. Energy in chemical reactions Many chemical reactions need some energy toget started; many chemical reactions give offenergy as they happen.

12. Atoms, elements and compounds Elements are made of just one kind of atom,whereas compounds are made of two or morekinds of atoms in fixed proportions. Elementsmay react to form compounds, andcompounds may be decomposed into theirelements. Energy input is needed to break acompound into its elements, whereas energyis given out when elements react to form acompound.

13. Reactions with OxygenOxygen has characteristic reactions withmetals and non-metals, forming oxides. Someof these oxides dissolve in water to formacidic or alkaline solutions. Some metals reactmore readily with oxygen than other metals.Corrosion of iron is an economically importantreaction which can be prevented through anunderstanding of the reactions between iron,water and oxygen.

14. Cellular RespirationThe reaction of oxygen with food releasesenergy in the cells of living things. (Links withLife and Living)


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The Western Cape Primary Science Programme (PSP) has been operating since 1985. The PSP is an in-service education organisation that aims to improve the quality of

teaching and learning in the most disadvantaged primary schools. We develop teachers’knowledge and skills and support them in their work with learners.

We focus on the critical learning areas of the Natural Sciences (including EnvironmentalEducation), Language, Mathematics and the Social Sciences.

The PSP offers a variety of courses, develops learning experiences together with teachersand offers support in their classes.

Based on this interaction with teachers, the PSP produces innovative materials, includingteacher resource books, learner task cards and display material. All our materials are

written in easily accessible language; include careful concept progression; many activitiesand investigations, and include good suggestions for assessment.

The PSP has a vision of an excellent primary schooling for all South Africa’s children, where all educators are highly skilled, committed and confident; and are well prepared

and resourced to teach.

Contact us for more information

Western Cape Primary Science Programme (PSP)Edith Stephens Wetland Park

Lansdowne RoadPhilippi.

PO Box 24158Lansdowne 7779

South Africa

Tel: 021 691 9039 Fax: 021691 6350

Email: [email protected]: www.psp.org.za

NPO: 015-822

WESTERN CAPE PRIMARY SCIENCE

PROGRAMME (PSP)


Documents

Matter and Materials [Grade 5 English]