Module 2: Science - Investigating Materials

Section 1: Investigating and classifying materials

1. Using games to explore materials

What earthly substance are we most in contact with? Soil; plants; water; wood; concrete; cloth...?

Did you think of nitrogen? We live our lives immersed (totally surrounded) in the gas nitrogen (80% of the air).

We start this section by looking at the ‘big picture’ of the matter and materials that make up our world. Case Study 1 and Activity 1 describe games in which pupils name, describe, sort and group matter and materials. These fun activities will help you establish what the pupils already know, a key part of good teaching in any topic.

2. Exploring properties of materials

As you get to know your class, it is really useful to talk to your pupils about their personal characteristics, things they can do, their likes and dislikes, and their strengths and weaknesses. A nice way to summarise this sharing talk is to ask them to draw a careful full-length self-portrait and to label their distinguishing features in one colour. They could use other colours to list and record their other different types of characteristics.

Now they will be ready to do the same thing when they consider the properties of different common substances (kinds of matter) they know from their environment. Activity 2 explores one way of doing this, using pictures.

In Case Study 2, a teacher introduces the idea of properties and the three states of matter (solids, liquids and gases) by starting with a single property –compressibility. Is this different to the way you usually introduce this topic? What other topics could you explore using this approach?

3. Organising investigations

Thinking and behaving scientifically is most evident when pupils investigate something practically.

Investigating is a key skill in science. It involves you and your pupils in:

• deciding on the question you are trying to answer;
• deciding what equipment to use;
• deciding what measurements and observations to take;
• deciding how to present your results and how they give you an answer to the problem.

Case Study 3 shows how teachers can lead a class investigation of an ‘unknown’ substance. If the pupils have experienced a teacher-led investigation, they will be better prepared to do their own independent investigations of other substances. So we strongly advise you to attempt the case study lesson plan given in Resource 4: Planning an investigation with your pupils before trying the Key Activity.

In the Key Activity you will support groups in planning, conducting and reporting on their own investigations of ‘unknown’ white powders.

Resource 1: The scavenger hunt game

 Teacher resource for planning or adapting to use with pupils

Students were given the ‘list of items’ in the central column. The table then shows how Groups A and D solved the challenge of finding examples of the items.

Note: The good thing about this game is its open-endedness. There are not ‘right answers’ – just ‘good’ answers and ‘very good’ answers.

Resource 2: Lesson plan: Which can be compressed – solid, liquid or gas?

 Teacher resource for planning or adapting to use with pupils

Yvonne used the activity below as the basis for her lesson.

First she got her pupils to do a quick spider diagram of their observations and knowledge about sand and this is what one of the better groups produced.

Then she decided that with an activity like this she could have given the pupils more ownership of the whole task. She made a worksheet (see below). She found that this change in approach really made a difference to the motivation, enthusiasm and learning of her pupils

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Resource 3: Sample of pupil’s work

 Example of pupils' work

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Resource 4: Planning an investigation

 Background information / subject knowledge for teacher

The plan of the lesson

Before the lesson, you need to find some dry clay and to crush, pound and grind it until it forms a fine dry powder. You don’t need much – just enough to give each group a heaped teaspoonful.

Step 1a – Investigation by observation, comparing and recording

Give each group a small dish or the flat lid of a jar to hold the powdered clay. Ask them to observe the substance carefully and to note down all their observations in the local language or English on paper or in their books.

(We found that it is important that the teacher doesn’t interfere with the groups at the start of the lesson. You need to give them a few minutes on their own to get started.)

Before the end of Step 1, ask these guiding questions to ensure that the observation has been thorough:

• Have you noted the colour of the substance?
• How does it feel?
• List other substances you know that are similar to this substance.

Step 1b – Communication

Ask the groups to feed back their observations. Summarise them on the chalkboard. This is a chance to bring languages together. If pupils answer in the local language, you can negotiate that the answers are written up in English.

At this point you can identify the substance as dry clay powder.

Step 2a – Prediction and recording

Get the groups to use a different colour or kind of pen/pencil for this step.

Hand out droppers with water, or show the class a small bottle of water. Here are the questions we prepared for this step:

• What will happen if we add just a few drops of water to this substance?
• Write down what you predict will happen if you add a few drops of water to the dry clay powder.
• How will the water change the clay?
• Write down all the changes that your group thinks will happen.

Then leave them to get on with the work. After about five minutes, you might give them a few prompts. Will the colour change? Will the appearance of the substance change? What will it feel like?

Step 2b – Communication

Add the pupils’ new work to the chalkboard using a different colour of chalk. Use English to record, and comment on their answers, extending the knowledge where necessary.

Step 3a – Investigation, observation and recording

Again, change the colour of the groups’ writing tools/pens.

Now let them add and mix a few drops of water. What changes do they see and feel? Were their predictions correct? Get them to investigate and write down what they notice.

Step 3b – Communication

For the third time, record the combined work of the groups on the board, using a third colour of chalk if possible.

Step 4 – Discussion

At this stage, ask the pupils to talk about and write down the things that damp clay can be used for. Record their suggestions on the chalkboard. Then get them to roll out a small snake from the damp clay in their dish/lid. Let them record or measure its length before they leave it in a safe place to dry. Ask pupils to record what they think will happen to the clay over the next few days.

You should now have a mind map on your board showing observations and predictions about clay.

Adapted from: Primary Science Programme Cross Curricular Work

Resource 5: Reading packaging

 Teacher resource for planning or adapting to use with pupils

Use these questions to help your pupils look at different packages.

http://www.assadsbakery.com/ shop/ images/ product_image_ab0282.jpg (Accessed 2008)

1. What does the picture tell us?
2. Does all the writing look the same?
3. Who makes this product?
4. What do we get in this packet?
5. Where does it tell us what is inside?
6. What do you see first? Why?
7. What do you see next? Why?
8. And then what do you see? Why?

Acknowledgements

Grateful acknowledgement is made to the following sources:

Photographs and images

Assad’s Bakery, The Laughing Cow packaging: http://www.assadsbakery.com/ shop/ images/ product_image_ab0282.jpg (Accessed 2008)

Text

Resource 4: Planning an investigation: Adapted from Primary Science Programme Cross Curricular Work

Every effort has been made to contact copyright holders. If any have been inadvertently overlooked the publishers will be pleased to make the necessary arrangements at the first opportunity.

Section 2: Exploring solids

Inquiry-based learning

For solids we can ask: ‘Where does this come from?’ Or: ‘What are its properties?’ And: ‘Can it be changed?’ (This often involves much more active learning than simply listening and hoping to remember. And if we don’t know – or can’t find out yet – there is always the possibility that one day, we will be thrilled to come across the missing information.)

Some solid substances are found naturally; others are manufactured. For example sand is a natural material and glass is a manufactured material. In fact, glass is manufactured from sand. Do you know what the actual process involves? Try to find out, and you are doing inquiry-based science.

Similarly, wood is a natural material obtained from trees, and paper is made from wood. Certain wasps chew wood into pulp to process it into ‘paper’ that they use to build the cells of their nest. People have discovered how to do the same thing. You could extend your inquiry and experiment with making your own paper from pulped wood.

Good starting points for this approach are informal discussions where pupils share ideas, raise questions and develop threads of inquiry that interest them. Case Study 1 shows how one teacher encouraged inquiry in her pupils. In Activity 1, you take this further with a class display and accompanying books made by your pupils.

2. Group work to investigate solids

In Section 1 we considered properties of matter when we compared the compressibility of solids, liquids and gases. Now we consider a few more properties in relation to solids.

Here is one to think about. Why is it that some solid objects feel cold to the touch and others don’t? Think of a wooden spoon and a metal spoon. When we first pick them up off the table, they must be at the same room temperature – yet the metal spoon feels colder.

Some materials carry, or conduct, heat better than others. Metals have the property of being good thermal conductors. The metal spoon conducts heat away from our hand and hence feels colder. The wooden spoon is a poor thermal conductor – it is a good thermal insulator.

In Activity 2 you investigate the property of solubility with your pupils. What other properties could you investigate? Electrical conductivity? Density?

Case Study 2 shows how a teacher with a large class supported groups of pupils to investigate one particular group of materials. (See Key Resource: Working with large classes)

3. Investigating irreversible changes

Here, we build on the first two activities by now considering ways in which matter can be changed. In science there are two types of changes pupils should consider:

• reversible changes – called physical changes;
• irreversible changes (changes that cannot easily be reversed) – called chemical changes.

Wax melting with heat and then solidifying again is a physical change. Dissolved sugar can be regained if the liquid is evaporated, so this is also a physical change. (Resource 4: Disappearing ice cube race gives one idea for a classroom activity around a physical change.) But glass cannot be easily turned back into sand – so this is a chemical change.

Case Study 3 shows one way that pupils can be challenged to think about chemical changes through a series of guided demonstrations. (SeeKey Resource: Using explaining and demonstrating to assist learning.)

When iron and steel rust (a chemical change) the metal loses its shape and strength. In the Key Activity you use a competition to get your pupils thinking about how they could slow down this chemical change.

Resource 1: Making a zigzag book

 Teacher resource for planning or adapting to use with pupils

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Original source: Stories into Books – D Dyer and A & V Kenyon (UCT 1990)

Resource 2: Looking at properties of solids

 Teacher resource for planning or adapting to use with pupils

Many objects are made from solids. Solids come in many different types, each with their own properties. The properties of the solid must be suitable for the object it is being used to make.

One activity for your pupils is to brainstorm all the different properties materials can have. Put out a display of objects around the classroom. Make a label for each object with some questions (see below for examples). Pupils, working in pairs, should spend 20 minutes looking at the objects and answering the questions about the materials to help them describe their properties.

Here are some suggestions for objects and labels for your display:

As your pupils look at the objects you should move around the class talking to pupils about what they observe. At the end of the time, gather your pupils back together and ask different pupils to tell you what they observed about one of the objects. Build up a list of properties on your chalkboard or class wall. If your pupils aren’t familiar with these property words in English, let them use them in their own language. You could put the English words on a display in your classroom to help pupils learn them.

This is an example list:

Make sure that your pupils can explain what each property means and ask them to draw a table in their books to show each property and an example of a material with that property e.g.

Now set your pupils some problems around choosing materials. Here are some examples:

A:     Isanga grows vegetables close to her house but she needs some way of protecting her young plants from birds. What sort of structure might she build? What materials should she use? Why should she choose these materials?

B:     Gagwala wants to put a new top on the table in his kitchen; the old one is very uneven and covered in burn marks. What sort of material should he use for the new table top?

C:     Samuel needs a bag to carry his books to school. What sort of material should he choose for the bag?

For each problem, pupils should think about what the object needs to do, and choose, from their list, the properties it must have. Then they can choose which material would be best in each case.

Resource 3: Lesson plan on solubility

 Teacher resource for planning or adapting to use with pupils

Disappearing acts

This is one way that you can talk to your pupils about the idea of solubility.

Think of a sweet like a strong mint or boiled fruit sweet. You put it into your mouth and enjoy the sweet pepperminty or fruity taste. But it doesn’t last forever. It gets thinner and smaller and eventually it is all gone. Where did it go? Into the solution of sugar and saliva you have been swallowing while the sweet is in your mouth. Your liquid saliva has been gradually dissolving (the process) the solid sweet as you suck it. The result of the dissolving process is a solution of sugar and saliva.

Perhaps you could have a competition in your class to see who can hold a soluble sweet in their mouth for the longest possible time. How did the winners do it?

One little chew and the sweet breaks up into smaller pieces – you have lost! Swirl it around in your mouth and you will have lost too! But if you can hold it in the cooler air on the tip of your tongue, where there is also less saliva, you might just be a winner.

Examples like this will give your pupils some ideas about the factors that affect solubility.

Investigating solubility

1. Each group of pupils chooses a factor around solubility to investigate. Some ideas are:

• temperature of the water (try hot, warm, room temperature and icy);
• changing the size of the sugar pieces (try four lumps: one lump, one lump broken into small pieces, one lump in grains and one lump which has been ground into powder);
• stirring (try no stirs, slow stirring and fast stirring).

2. Put these questions on the chalkboard to help your pupils plan their investigations:

• What do you want to find out?
• What do you predict will happen?
• What equipment will you need?
• What will you change each time?
• What will you keep the same (to make sure the test is fair)?
• What will you actually measure?

3. Make sure each group keeps all the other factors the same (constant). Only one factor must be different for each group. For example, if they are investigating stirring, they must use the same amount of water at the same temperature and the same amount of sugar each time.

4. Ask your pupils to record their results in the form of a bar graph such as that below, which shows how many minutes it took for one spoonful of sugar to dissolve in the same volume of water at different temperatures.

Background knowledge for the teacher

Model of dissolving

This is a clearer picture of what happens when solid matter dissolves in liquid. A soluble solid comes into contact with a liquid solvent. The liquid ‘unglues’ the particles of the solid, so they can move, mix in and slip freely between the particles of the liquid.

The factors that affect the time it takes for a solid to dissolve are:

• temperature of solvent (faster in hot water);
• size of solute (faster with small grains);
• movement of solvent (stirring makes dissolving fast).

An example – dissolving salt

The teaspoon of salt is the solute. The water in the jar is the solvent. Once the salt is added, the process is called dissolving. The product of dissolving is a saline (salty) solution.

If more salt is added until no more will dissolve, we have a full or saturated solution.

Resource 4: Disappearing ice cube race

 Teacher resource for planning or adapting to use with pupils

Organise your class into groups of four or five.

1. For each group, choose someone to be an ‘independent observer’. This observer will report:

• how well the group worked together;
• exactly what the group did to solve the problem;
• how long they took to do it.

2. Here is the challenge: Each group has a medium-sized ice cube in a polystyrene/plastic cup. Find the best way to make the ice cube disappear without a trace, not even a single damp spot!

3. The group observer records the results in a table like the one below on the chalkboard.

4.Every minute, each group observer puts an ‘X’ if there is a trace of the ice cube left.

5.Before the race begins, give pupils time to talk and plan how they will get the ice cube to disappear.

Time: Mins

Group

6. Which group found ways to make their ice cube disappear the fastest? Who had the second best way? Which group was the least successful?

7. Give the observers a chance to report back on how well each group worked together. They could use an assessment scheme like this one to score each group.

Follow up the ice cube race

Discuss the changes pupils saw as the ice cube disappeared. How does solid ice change (melt) to liquid water and eventually change (evaporate) into an invisible gas or vapour? These are called changes of phase. Finish the lesson by doing this quick quiz. Do this quick quiz:

• List the things you can do to speed up the process of getting solid ice to change into liquid water.
• What is the scientific term to describe the change from a solid to a liquid?
• List the things that speed up the process of turning liquid water into a gas like water vapour.
• What word do we use for the change from a liquid to a gas?

Answer hints:

Factors that affect melting and evaporation are:

• heat;
• size and shape;
• moving air;
• pressure.

Pupils could write a short report on what they learned in the race for homework.

Resource 5: Molecules and atoms

 Background information / subject knowledge for teacher

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Original source: Primary Science, Developing Subject Knowledge, Jane Devereux

Acknowledgements

Grateful acknowledgement is made to the following sources:

Photographs and images

Making a zigzag book: Stories into Books – D Dyer and A & V Kenyon (UCT 1990)

Molecules and Atoms Teacher Information: Primary Science, Developing Subject Knowledge, Jane Devereux

Every effort has been made to contact copyright holders. If any have been inadvertently overlooked the publishers will be pleased to make the necessary arrangements at the first opportunity.

Section 3: Looking at liquids

1. Exploring prior knowledge through brainstorming and demonstrations

Because water is so important on Earth, we make it the emphasis when pupils learn about liquids. Case Study 1 tells how one teacher recorded pupils’ ideas about water on a mind map that would be added to throughout the topic. Could you use mind maps as a starting point for this topic? After making a mind map, or using another way to find out pupils’ understanding, practical demonstrations are important. These reinforce ideas and show how things work or happen.

In Activity 1 you undertake just one of the many possible teacher demonstrations that can be useful to show the properties of water – a waterwheel.

From ancient times people realised the power of flowing water. If water could be channelled to flow over or under the blades of a wheel, it makes the wheel spin. This can be used to drive other machines that do work like grinding meal or even generating electricity.

If you do not have access to sufficient water for this demonstration, we suggest you try another demonstration such as ‘How would you show there is water vapour in the air in the desert?’ (Resource 1: Surviving in the desert outlines this activity.)

2. Focus on drinking water

Some people are predicting that future wars will be fought over water – an alarming thought. Water is our most precious resource. How do we ensure that pupils appreciate water and value using it wisely?

The amount of water found on Earth is about 1,400 million million litres. Most of it is found in three places:

•  

  • oceans and seas (97%);
  • frozen, as ice (2%);
  • underground (1%).

There is also some water in lakes and rivers, in the atmosphere and in living things.

Case Study 2 shows an interesting way of combining science and language in a drama activity about water supply. It is important to use a range of different types of activity in science as each pupil will have a preferred learning style – some will learn best through doing, some through seeing and some pupils will be happiest listening.

In Activity 2, you plan and carry out a demonstration that shows how to extract clean drinking water from salt water or dirty water. As with all demonstrations, we suggest you try this out before the lesson and think carefully about the questions you will ask the pupils during the demonstration.

3. Solving problems through experiments

For the final part of this section, we build on the ideas in the first two sections to ask pupils to solve the problem in the Key Activity (read this now). This activity uses investigative skills – predicting, planning, recording and presenting findings. Does this kind of activity keep your pupils interested? Can you think of other topics in the science curriculum where you could use this? Share your ideas with your colleagues. Perhaps you could start a journal of investigations in your school.

Often, in science, the unexpected happens. In Case Study 2, one teacher uses a demonstration to challenge his pupils’ thinking – he shows that a metal needle floats. How is that explained? This type of activity gives you an opportunity to assess pupils’ understanding and to add to your original class mind map.

Resource 1: Surviving in the desert

 Teacher resource for planning or adapting to use with pupils

Even if you are stranded in the desert with no water, you can collect water from the soil to drink if you have a clear piece of plastic sheeting and an empty jar or container. The diagram shows how you can do this:

Can you explain how this works?

• The heat from the sun causes water in the soil to evaporate.
• The water vapour rises in the air.
• When it meets the cooler sheet it condenses and turns back to water.
• The water runs down the inside of the sheeting and collects in the jar.

Could you try this with your pupils?

Resource 2: Sample mind map

Preliminary activity – creating a mind map of all we know about water

 Teacher resource for planning or adapting to use with pupils

Pupils work in small groups, talking and thinking about different aspects of water, and creating a mind map of one particular aspect. The aspects set out include:

• properties of water;
• where water is found;
• pollutants;
• uses of water;
• sources;
• dangers;
• cultural beliefs.

This is a very valuable activity. Instead of testing what the pupils don’t know, they have an opportunity to share what they do know. They are encouraged to help one another, not to compete against one another. This is a good way to assess what the pupils know and how well they work as a group.

The following page shows a mind map of all the information teachers thought of at a workshop:

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Resource 3: Instructions for making a waterwheel

 Background information / subject knowledge for teacher

You will need a knitting needle, glass or plastic tube e.g. pen case (which the knitting needle can pass through), string (about 1. 5 m), modelling clay/prestik and stiff cardboard.

Cut out the eight blades for the waterwheel from cardboard – they should be rectangles about 6 cm by 4 cm.

Thread the knitting needle through the glass tube.

Tie the end of the string round the glass tube and cover the end with lump of prestik.

Then put a larger piece of prestik over this and stick the blades of your wheel into the prestik at regular intervals.

Tie a weight to the other end of your string.

Then try out your wheel. Hold the knitting needle and pour water over the blades on one side.

Resource 4: Making a big book

 Background information / subject knowledge for teacher

Reasons for making a big book

• If the books are interesting, then pupils learn that reading is interesting.
• If the books are boring and carry little relevant meaning, pupils see reading as a chore that has little to do with them and their interests.
• If pupils get the chance to actually make a book, they can see themselves as authors, and this is a very powerful thing.
• If pupils never find themselves and their lives in the books that they read, then they learn that books have little to do with them and they are less likely to want to have much to do with books.
• In other parts of the world, many pupils are encouraged to make their own books at school (together or on their own). These pupils love reading and read well.
• There is also a trend to use very large books for the early stages of reading so that learning what reading is about can be a shared activity. With a large book, a teacher can help the whole class to become readers.

Thank you for a drink of water

This book tells the story in reverse of how a child gets a drink of water. It traces the story back to the original provider – the sun. You could adapt this story to your own setting such as a village camp or town and make your own book with your pupils. Make sure all your pupils are involved. Plan out each page and then organise different groups to complete each page. Your pupils could show their book to other pupils in the school.

Adapted from: Primary Science Programme Workshop Report – Kenyon & Kenyon (1996)

Resource 5: Surface tension – information for teachers

 Background information / subject knowledge for teacher

If you had never seen a steel needle floating on the ‘thin skin’ of the surface of water, you might have been as surprised as your pupils are likely to be when you demonstrate this. But what is the explanation?

Think it out for yourself. Try to imagine the actual particles of water. In your mind’s eye, see them free to flow and move past and between each other. But they are always being held together by weak forces of attraction. This is happening in all directions. At any one moment in time, any one particle will have neighbours on all four sides (left, right, front and back). There will also be neighbours above and below. Do you get the picture?

Now think of a particle at the surface. It has no particles above it. That leaves the particles at the surface with extra attractive force to spare, so the particles at the surface will hold together more strongly. This creates a tough, fairly strong, temporary skin across the surface. Scientists agree to call this extra pull between surface particles of certain liquids, surface tension.

Water has a much higher surface tension than most other liquids. You might like to try the experiment with other liquids to show this.

Can your pupils think of other examples of surface tension?

Other examples include the shape of water droplets and insects walking on water.

A water droplet – surface tension changes their shape

The insect can walk on the water because of the surface tension on the surface of the water.

Original source: http://citt.ufl.edu/ Marcela/ Sepulveda/ html/ en_tension.htm (Accessed 2008)

Acknowledgements

Grateful acknowledgement is made to the following sources:

Photographs and images

A water droplet: http://citt.ufl.edu/ Marcela/ Sepulveda/ html/ en_tension.htm (Accessed 2008)

Insect walking on water: http://citt.ufl.edu/ Marcela/ Sepulveda/ html/ en_tension.htm (Accessed 2008)

Text

Resource 4: Making a big book: Adapted from Primary Science Programme Workshop Report – Kenyon & Kenyon (1996)

Every effort has been made to contact copyright holders. If any have been inadvertently overlooked the publishers will be pleased to make the necessary arrangements at the first opportunity.

Section 4: Investigating air

1. Focus on language

Classroom teachers often resort to teaching science with talk in the mother tongue and writing and testing in the target language, such as Arabic, Kiswahili, English or French. Yet much valuable language learning can take place in science lessons because the language to be learned is ‘linked to action’.

This is the focus of Case Study 1. Even the action of ‘pointing out’ something in a short demonstration can help you assess pupils’ learning. What pupils say, as they point out something, reveals what they know. You follow this up in Activity 1 with a series of investigations in which the emphasis is on careful observations and deductions – what do pupils’ observations tell them about the nature of air? Encourage the use of lots of different descriptive words; this is an ideal time to reinforce language learning.

2. Exploring the properties of air

In the Key Activity of Module 1 Section 4, pupils observed and researched things that move in air. Activity 2 integrates well with that work and could be done at the same time. But you could start by observing and comparing non-living things, for example sheets of paper, parachutes, kites and airplanes. It can be useful to observe and compare things dropping, or falling through air. It begins to give pupils the idea that air must consist of small particles that are free to move, but nevertheless get in the way and push against things as they drop.

In Case Study 2, we read how a teacher uses a pupil’s question to get the class talking and thinking about how airplanes stay up. Activity 2 starts by getting the children observing using different languages, and then moves to a practical challenge where pupils’ thinking is revealed by what they do to solve a problem.

3. Using models to explain scientific ideas

The activities in this section will have begun to give the pupils some sense of what is called ‘the particulate nature of matter’. If you watch the way a sheet of paper cuts its way through the air as it falls, you can almost imagine the invisible particles getting in its way. Paulina mentioned particles when explaining the low pressure above the wing of an airplane.

It’s difficult to show pupils the particles in air – they are far too small to see even with a microscope, so we need to use models to help our pupils build a picture of what air is like. In the Key Activity, you use the pupils to be particles in the air. Many pupils enjoy learning by touching and doing, they enjoy being active and find it easier to remember what they have actually experienced.

In Case Study 3, one teacher builds a model to show how air is made up of a mixture of different particles and follows this up with investigations around breathing. Both types of approach give you the opportunity to assess your pupils’ learning.

Resource 1: An introductory ‘air’ lesson

 Teacher resource for planning or adapting to use with pupils

Note: Plan to start the double period/one-hour lesson just after a break, but do the introduction just before break.

Begin by giving one pupil a bucket and asking them to go outside to fetch you half a bucket of water. Then give another pupil a large clear plastic bag and ask them (you might want to pick a pupil who can take a joke) to go outside to fetch you half a plastic bag of air. This will surely cause a brief moment of puzzlement as it is of course a bit of a joke – but it proves a point – ‘air is all around us’. Insist that the air is fetched from outside. Then hand out three or four more clear plastic bags with which to catch air from:

• under a desk;
• in the far corner;
• by the window;
• from one pupil’s own lungs.

Emphasise to your pupils that air is all around us.

Divide the class into eight groups. Each group should choose a leader. Explain that when they come back after the break, they will take turns to work for ten minutes at each of four workstations to find out some more about air. This is called rotating group work.

During break time, set out the workstations with the necessary equipment, and a copy of the workcard for each station. Work cards are set out in Resource 2: Air experiments.

You could get the eight group leaders to help you do this so that they have been prepared for leadership roles in what is to come.

Then it is over to the groups to do the work. At the end of the lesson, ask pupils to summarise what they had to think about and what they feel they learned at each workstation.

Resource 2: Air experiments

 Teacher resource for planning or adapting to use with pupils

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Resource 3: ‘What lifts an airplane?’ Practical activities to carry out with your class

 Teacher resource for planning or adapting to use with pupils

The teacher at KamonkoliHigh Schoolmade Paulina photocopies of some notes from a primary science workshop that he had once attended.

These notes are copied for you below. Paulina worked through these activities with her class; they were fascinated and kept asking more questions.

One of the questions that children ask is ‘What keeps something heavy like an airplane up in the air?’ This is a really good question. Their teacher explained that there were a number of practical things that could be done to hint at how an airplane was lifted. But it does take quite careful explaining. One way to get people thinking is to compare blowing ping-pong balls with two different tools. You need the cardboard tube of a used toilet roll and a plastic funnel. You want to blow the ping-pong ball against the ceiling. Ask the class to predict which tool will be the best ping-pong ball blower – the toilet-roll tube or the plastic funnel. Then let them try. Now this is something to think about because the result is quite unexpected!!! What is happening in the funnel that holds the ball down so strongly? It can only be the air! Another teacher gives us another practical activity to try. Make a little bridge of paper by folding down two sides. Use a straw to flow air under the ‘bridge’. What do you predict will happen? What does happen? Why does the bridge collapse inwards and not bulge outwards? A third thing to try is to fold a sheet of A4 paper slightly off-centre, and then to glue down the two ends to form a model of the wing of a plane or a bird. Blow straight against the front edge and see what happens. The paper model lifts up. Why?
Clues Think of a group or cluster of people walking along a road. They hear something dangerous behind them and start to run away. What happens to the arrangement of people? Yes. They tend to spread out as their speed increases. Now, try the same thing with a handful of marbles. First roll them slowly across a smooth surface and they tend to stay clumped together. Then roll them more speedily and they tend to spread out. When air is forced to move more quickly over a curved surface or through a narrow space, the particles spread out. This means that there is less pressure. So you can get a strong force or lift from the air on the other side. It can be useful to observe and compare things dropping or falling through air. First we tried paper races. We compared the way two identical bits of paper, labelled A and B, fall through air. Why does a crumpled sheet fall more quickly? Trying to find the best words to describe the observed movement of the flat sheet and the crumpled ball makes for an excellent multilingual language activity. Paper A (flat) Floats Wobbles Twists Dives Zigzags, like a leaf or a feather Paper B (crumpled) Drops Straight Fast Falls, like a stone

Adapted from: Primary Science Programme Grade 4 Air Workshop Report

Resource 4: The slow paper race

 Teacher resource for planning or adapting to use with pupils

Maximise

Adapted from: Primary Science Programme Grade 4 Air Workshop Report

Resource 5: Finding out more about air

 Teacher resource for planning or adapting to use with pupils

Maximise

Maximise

Acknowledgements

Grateful acknowledgement is made to the following sources:

Photographs and images

Resource 3 : ‘What lifts an airplane?’ Practical activities to carry out with your class : Adapted from Primary Science Programme Grade 4 Air Workshop Report

Text

Resource 4: The slow paper race: Adapted from Primary Science Programme Grade 4 Air Workshop Report

Every effort has been made to conta ct copyright holders. If any have been inadvertently overlooked the publishers will be pleased to make the necessary arrangements at the first opportunity.

Section 5: Wise use and reuse of materials

1. Raising awareness of resources

So far in this module we have explored the origins of different materials, considered how they may be classified by their properties and how they may be processed and used in different ways depending on their states.

In this section, we try to make our pupils aware that we have limited supplies of many materials on the Earth. In Case Study 1, we read how a teacher introduces this idea by brainstorming a list of materials in terms of ‘renewable’ and ‘non-renewable’. (See Key Resource: Using mind maps and brainstorming to explore ideas.)

One very important resource that is in limited supply is crude oil. Do you know how many materials are made from crude oil? Crude oil is a mixture of liquids. It isn’t any use until the mixture has been separated at an oil refinery. The crude oil is boiled and each part of the mixture boils at a different temperature. This separation is called distilling and the different parts of the mixture are called fractions. Each fraction is then used to make different products.

In Activity 1, you use a diagram to help pupils appreciate how dependent we are on crude oil. You could follow this up with a display of products based on crude oil in your classroom – pupils could draw pictures or use images from catalogues or magazines.

2. Developing responsible attitudes

From the previous work, pupils will have begun to realise that we need to think carefully about using non-renewable resources. We need to start thinking how we can act to become part of the solution to this problem and not just part of making the problem worse. It is good to get pupils involved in positive action that benefits the environment in some way.

In Case Study 2, a teacher encourages the pupils to go out into their own community and think about the impact of people on their environment. (If you try the same activity and don’t have coloured paper, you could divide to the wall into two areas.)

In Activity 2, we suggest your class researches, designs and carries out a long-term compost-making project. You can start by introducing the terms ‘biodegradable’ (rots away) and ‘non-biodegradable’ (doesn’t rot away) and explaining what causes rotting – bacteria. Pupils will be able to give you many examples of materials in each of these groups – this could be a brainstorm activity.

Later, you might want to go into income-generating production of compost, which would involve systems for safely collecting local compostable waste and its subsequent sale or use in a school vegetable garden.

3. Group work with a focus on recycling

Pupils can explore other ways to recycle or reuse what would otherwise be waste material. People in poorer communities do this in very creative and imaginative ways out of necessity. Studies of people like the Khoi-san (Bushmen) in South Africa show how, in the past, they wasted almost nothing at all and made a minimal ‘human footprint’ on their natural world, treating it with enormous respect. How do we compare in modern times? (Resource 4: Ecological footprint gives information on calculating the size of your ‘footprint’ on the Earth.)

What kind of recycling is going on in your local community? Case Study 3 shows how one teacher and her pupils survey the local community for evidence of recycling.

In the Key Activity, we suggest you encourage your pupils to do an integrated science and technology exercise. They work at designing and making articles from waste and sell these at a special ‘entrepreneurial’ day to raise funds for the school or class.

Resource 1: Renewable and non-renewable resources

 Background information / subject knowledge for teacher

Note: You might see how the teacher has started by accepting most of the suggested items the pupils present and has tried where possible to use their own words. This gives them confidence to add more. If the teacher rephrases everything they suggest into textbook-type language many children get discouraged – accepting and working with their actual words is very important.

You might also have noticed how the teacher has steered the attention to energy aspects – by adding in a sub-heading. Depending on where they live, pupils might also know of natural gas, which is considered a non-renewable resource.

Resource 2: Products from crude oil

 Teacher resource for planning or adapting to use with pupils

This diagram shows an oil distillation column.

Maximise

Original Source of diagram: Oxford Science Programme Book1, published by OxfordUniversity Press, p. 92 (1990)

Teaching ideas

Teaching ideas would include making posters of products and by-products of crude oil using collages of magazine and newspaper adverts (you could show the products or brand names and symbols). Alternatively, you could make a display of empty containers. Products to consider include paraffin, diesel oil, petrol, lip balm, lipsticks, vaseline, lubricating oils, candles, tar and plastics.

Nigeria’s oil industry

Image from http://www.offshore-technology.com/ projects/ ekpe/ images/ ekpe5.jpg (Accessed 2008)

As of September 2004, Nigeria was the largest oil producer in Sub-Saharan Africa, the fifth largest petroleum exporting country in the organisation of petroleum exporting countries (OPEC). Nigeria produces 30% of the total oil production in the African region. Oil income has historically provided about 95% of Nigeria’s foreign exchange earnings. The source of Nigeria’s wealth is the Niger Delta, a wetland of about 70,000 sq km. The Niger Delta is made up of nine oil producing states and has an estimated population of about 20 million people, amounting to about 16.7% of the Nigerian population (120 million).

Map of the Niger Delta

http://www.usip.org/ events/ 2005/ 1107_niger.html (Accessed 2008)

Adapted from: http://en.wikipedia.org/ wiki/ Nigeria_oil#Geology_and_reserves (Accessed 2008)

Resource 3: Making compost

 Background information / subject knowledge for teacher

The best and cheapest way to make garden soil better is to make your own compost. It only costs effort and a little bit of time and care.

Choose an out-of-the-way part of the school garden that is quite sunny. Clear away any weeds and rubbish.

When you have an open space, one of the pupils can mark out a circle with a radius of about 75 cm. If this pupil stands in the centre of the circle and turns around while holding out a walking stick, a good circle will have been drawn.

Take spades and dig up the soil in the circle. Dig to the depth of the blade of the spade. Use a garden fork to make the soil in the circle loose.

Make a small pile of spare soil next to your circle by moving about a third of your loosened soil from the circle.

Stick a central pole or straight branch into the soil in the centre of the circle.

Now you can start the compost-making process. Put a layer of twigs and old leaves you have collected on top of the loose soil. The more you have the better.

Next, put down a layer of stalks and stems from plants and any kitchen waste (potato peelings, old tea bags or tea leaves, eggshells). You can even add shredded scraps of paper.

Then add a dry layer of grass cuttings, dry grass or old dry leaves.

Finish by putting a thin layer of soil on top. Use the loosened soil from the pile next to your compost heap.

Go on adding more layers:

•  

  • first stalks, stems, twigs and leaves;
  • then kitchen waste and green cuttings;
  • then dry grass, old leaves and manure (if you can find it);
  • finish each layer with a last layer of soil.

Sprinkle a little water – but don’t make the compost heap too wet.

The height will drop as the matter rots down. Then you can add more layers over time. Always keep a layer of soil on the top – this deters the flies.

Resource 4: Ecological footprint

 Teacher resource for planning or adapting to use with pupils

Access the website below to take part in the ecological footprint quiz. This is displayed in many different languages.

http://www.myfootprint.org (Accessed 2008)

Overview

The ecological footprint is a tool that measures how much land and water area a human population needs to produce the resources it uses and to absorb its waste.

In order to live, we consume what nature offers. Every action has an impact on the Earth's ecosystems. This is of little concern as long as human use of resources does not exceed what the Earth can renew. But are we taking more?

Today, humanity's ecological footprint is over 23% larger than what the Earth can regenerate. In other words, it now takes more than one year and two months for the Earth to renew what we use in a single year. We are surviving by using up the Earth’s resource stores. We are both using up non-renewable resources such as minerals, ores and petroleum but also renewable resources such as fish stocks, animals, forests and groundwater – we are using these up faster than the Earth can resupply them. We depend on these ecological assets to survive. Livelihoods disappear, resource conflicts happen, land becomes barren and resources become increasingly costly or unavailable. This is made worse by the growth in human population, as well as by changing lifestyles that place more demand on natural resources.

By measuring the ecological footprint of a population (an individual, a city, a nation, or all of humanity) we can assess how much of the planet we are using, which helps us manage our resources more carefully. Ecological footprints enable people to take personal and collective action so that we live within what the Earth can regenerate.

The challenge and the goal: sustainability

Sustainability is a simple idea. It is based on the fact that when resources are used faster than they are produced or renewed, the resource is depleted (reduced in number) and eventually used up.

In a sustainable world, people’s demand on nature is in balance with nature's capacity to meet that demand.

Calculate your ecological footprint

Answer the following questions to see how big your ecological footprint is. Add up your points, indicated at the end of each question (for example [2]) to see if you are making a HIGH, medium or low impact on the environment around you. Remember, the smaller the footprint, the better!

1. How much of the food that you eat is processed, packaged and from far away?

a) Most of the food I eat is packaged and from far away. [3]

b) About half the food I eat is packaged. [2]

c) Very little. Most of the food I eat is unprocessed, unpackaged and locally grown. [1]

2. What is the size of your home?

a) 30 sq m or smaller [1]     similar size to a large truck

b) 90–130 sq m [2]              similar size to half a football pitch

c) 200 sq m or larger [3]      similar size to a full football pitch

3. Do you bicycle, walk, or use animal power to get around?

a) Most of the time [1]

b) Sometimes [2]

c) Rarely [3]

4. On average, how far do you travel on public transportation each week (bus, train, ferry, shared taxi)?

a) 25–100 km per week [3]

b) 20 km per week [2]

c) 0 km per week [1]

5. On average, how far do you go by car each week (as a driver or passenger)?

a) 0 km per week [1]

b) 250–500 km per week [2]

c) 700 km or more per week [3]

6. Compared to people in your neighbourhood, how much waste do you generate?

a) About the same [2]

b) Much less [1]

c) Much more [3]

Now add up your points and refer to the table below.

Resource 5: Lesson plan: Finding the best waste material ball

 Teacher resource for planning or adapting to use with pupils

It is a good idea if you help your pupils to think about how you will judge the best ball before they start making balls from any safe, reasonably clean, waste material.

First, start with a brainstorm where you and your pupils list the qualities of a ‘good’ ball. Expect or work towards ideas such as:

A good ball is:

1. properly round and the right size;
2. rolls straight;
3. bounces well;
4. strong;
5. soft enough to catch.

Your pupils might have some more ideas – make a list on the chalkboard.

Second, you and your pupils need to discuss how each quality can be measured.

• Properly round and the right size: Does the ball fit evenly through a special wire or cardboard hoop of the exact/right diameter no matter which way up it is? Can you hold it comfortably?
• Rolls straight: Measure by actually rolling – you need to decide how far to roll it along a line on the ground.
• Bounces well: You will need to drop the balls from the same height and measure how high they bounce back to compare them.
• Strong: This might have to be tested by actual use. How long before repair or replacement is needed?
• ‘Soft enough to catch’: Does it hurt your hands when you catch it?

Finally, you need to set scores for the tests you have established and then try them to see if it works (one example is given below).

You will need to develop this score sheet on the board with your pupils. You could divide your class into groups – each group to develop the scores for one property.

Give each group time to find materials and make their ball.

Now ask each group to test their ball against the criteria. What is the score for each criteria? What is the overall score?

You may find that you and your pupils need to change the criteria once they have made their balls. This would show that they are developing critical thinking skills. They may also think of adding qualities, for instance, appearance. That also deserves some praise.

Acknowledgements

Grateful acknowledgement is made to the following sources:

Photographs and images

Oil distillation column: Oxford Science Programme Book1, published by Oxford University Press, p. 92 (1990)

Oil rig: http://www.offshore-technology.com/projects/ekpe/images/ekpe5.jpg (Accessed 2008)

Map of the Niger Delta: http://www.usip.org/ events/ 2005/ 1107_niger.html (Accessed 2008)

Text

Nigeria’s oil industry: Adapted from http://en.wikipedia.org/wiki/Nigeria_oil#Geology_and_reserves (Accessed 2008)

Ecological footprint: http://www.footprintnetwork.org (Accessed 2008)

Every effort has been made to contact copyright holders. If any have been inadvertently overlooked the publishers will be pleased to make the necessary arrangements at the first opportunity.