Put pictures with different substances for learners to sort.

Instructions:

Note to teacher:

Explain to the learners the meaning of the word: property. Some learners know a "property" is a thing owned by someone as a piece of land or house. In science the word "property" describes a special quality or characteristic of something. Properties are common when the same qualities belong to most substances in the group studied.

Explain to the class what they have to do in the activity: "Exploring the properties of solids". Let the learners work in pairs. They must do the activity and write down their findings. Assist them to draw a concept map. Follow-up with a class discussion to make sure that every one knows what the common properties of solids are.

When is it a solid?

The word "property" has different meanings. We say this house is the property of Mr Mabusa, he is the owner of the house. When we use the word "property" in science we look at what make that kind of matter special; how does it behave different from other kinds of matter. For example when you shift a chair it will have another place, but it still has the same shape. This is not the same for liquids, they change shape when you shift them from one container to another.

Activity: Exploring the properties of solids

What you will need:

What you h ave to do:

1. Work in pairs.

2. Use the questions set to test each solid.

- How does it feel, hard or soft?

- Does it make a sound when you knock on it?

- Does it break easily? Can it break?

- Can you put your finger through it?

- Is your hand dry or wet after handling the object?

- Does it change its shape when you put it in something else? Say you put the pen in your suitcase?

- How will you describe the shape, is it fixed, does it remain the same?

- Describe the space taken up? Is the space small, large, does it change when you shift it to another place?

3. In your workbook draw a concept diagram of the discovered properties of each solid.

4. Write down those properties that were the same (common) for all the solids you investigated?

Note to teacher:

What you have to do before presenting the lesson:

Collect the materials needed for the practical before you do the activity. You can ask the learners to bring some of the materials to school, but be prepared to supply the materials as learners sometimes do not have the resources or forget to bring them to school and then you are stuck. Take care that you have soap, water, a basin and paper towels for learners to wash their hands after doing the practical.

How to present the lesson:

Pour about 2 tablespoons of the suggested liquid in a container. Divide the class in 5 groups. Give each group a different liquid, a saucer and another container. Go through the activity with the learners and explain to them what they have to do. Discuss the safety rules and warn the learners NEVER to taste an unknown liquid - methylated spirits and paraffin is poisonous. Walk to each group and help the groups that are not sure what to do. Let the learners to wash their hands after doing the practical. Go through the concept maps of the groups in a class discussion to make sure that everyone knows how to draw a concept map. Let the learners on their own do the questions set in their workbooks. Go through answers with the class.

When is it a liquid?

You know many liquids, they can be water, paraffin, baby oil, fruit juices, methylated spirits, but what are the common properties of liquids? When scientist want to know more about something they set up questions and then they try to answer the questions by doing the experiments.

What you will need:

What you h ave to do:

1. Work in groups. Each group tests a different liquid.

2. Group leaders:

- collect a liquid from the teacher in a container

- take another container and a saucer to your group

3. Use the questions set to test each liquid. DO NOT TASTE THE LIQUID!

- How does it smell?

- Can you put your finger through it?

- Is your hand dry or wet feeling the liquid?

- Can you dry the liquid up with a cloth?

4. Put a small amount of the liquid in the saucer and leave it for a while on a hot place.

- Was it easy to pour the liquid from one container to another?

- Can the liquid flow or spread out on a saucer?

- Does the liquid "fly away" by itself?

- Did the shape of the liquid change when you poured it into another container?

- How will you describe the shape of the liquid, is it fixed does it take the shape of the container?

- Did the amount of liquid remain the same after leaving it in a hot place?

- What do you think happened to the liquid?

5. WASH YOUR HANDS AFTER HANDLING THE LIQUID.

6. In your group, draw a concept diagram of the discovered properties of the liquid that you investigated.

7. Report your group's findings to the rest of the class.

QUESTIONS

1. Write down the safety rules for this investigation. Why are these safety rules taken?

Don't taste any unknown liquid, wash your hands after handling unknown liquid they can be poisonous.

2. Draw a concept map for the properties of FOUR liquids.

Concept map should show all liquids: finger passes through, wet, cloth soaks up, flow when poured, spreads out, remains in container, liquid takes shape of container, paraffin, methylated spirits have a smell, water- no smell, water and methylated spirits 'fly away' easily when hot

3. Write down those properties that were the same (common) for all the liquids investigated?

Liquids: flow and can be poured, shape is not fixed they take the shape of the container.

When is it a gas?

Cooking using a gas cylinder (Megan's photo)

A patient in hospital with an oxygen mask on. http://www.flickr.com/photos/donhomer/4037179901/

Balloons filled with helium gas. http://www.flickr.com/photos/92833011@N00/1160780781/

Scuba diver with an oxygen tank to breathe under water. http://www.flickr.com/photos/87241965@N00/371591593/

Do you know any gases? What about the gas used in stove to cook food? Have you noticed the gas coming out of the exhaust of a motor car? In hospitals there are cylinders filled with oxygen gas for patients with breathing problems. The air you breathe in has oxygen gas. The gas carbon dioxide is breathed out.

Insert a pictures

Picture 1 A child blowing balloons of different sizes

Picture 2 Aerosol (or perfume) sprayed in front of a class, learners in front smell it first. Later the whole class is filled with the smell.

Picture 3 Pressing on a balloon filled with a gas.

1. Study the pictures above.

2. Make a tick to the picture or pictures that shows the property.

Comparing solids, liquids and gases

Some people talk about three phases of matter while others prefer to talk about the three states of matter. The states or phases of matter are solids, liquids and gases. We have carefully investigated these three phases of matter.

Summary

(A riddle is a question not easily understood at first, that has a clever answer.)

1. Discuss in your groups and write ideas down on what could have happened to the ice cubes.

2. Write down some of your ideas from the discussion in your group.

3. Report back to the class.

When heat is added to some liquid substances the temperature keeps rising. This can cause a change in the state of the liquid. When water is heated steam forms. Steam is water in its gas state or phase. We can also say liquid-water changed to a vapour, it evaporated. When a liquid changes to a gas or vapour the process is called evaporation.

Do the activity below to investigate changes in substances

Demonstration a ctivity: Heating to cause phase change

W hat you will need

What you have to do

1. Boil the water until a cloud comes out.

(do not put the lid on the kettle for your experiment to work better)

2. Put a glass or mirror 30 cm above the boiling kettle
(you need to wear gloves made of thick material or use a towel to avoid burning your skin)

Answer the questions in your workbook.

3. What is the formed cloud called?

4. What is the process called when water changes to steam?

5. Observe and write down what happens to the steam when it reaches the glass.

6. What is the process called when steam changes to water?

What you have learnt

Water from the kettle boiled and turned into steam, the water evaporated. Water changed from the liquid to the gas phase. Steam rose up and as it went against the glass, it started cooling down and turned back to liquid. Steam condensed to form water.The phase change is from the gas phase to the liquid phase.

1. Watch the video on how ice cream is made and then discuss the questions that follow.

http://www.youtube.com/watch?v=K-7s7WrTX7k orhttp://www.youtube.com/watch?feature=fvwp&NR=1&v=aksSoUHp_Tg

2. Before mixing all the ingredients to make the ice cream, in which phase or state were the ingredients? Use the table below to record your answers.

Phase changes are reversible

Insert a pictures from Google images showing oxygen in its liquid phase.

Temperature is the key to which state some substances are. The illustration shows oxygen gas in its liquid state at a very low temperature.

Changing temperature in substances like ice means that the substance will also change its phase. When Mashudu left ice lollies in the sun, the phase of the ice lollies changed to liquid. If you want to change the phase of the ice lollies back to ice, you reverse it by putting the lollies packets in the freezer. Mashudu's ice cubes disappeared or evaporated because of too much heat. It is very important to know that other substances act in the same way as water. This means for example that methylated spirits will also freeze at a low temperature or or evaporate when heated.

Melting and solidification of materials

Group activity: Melting and solidifying substances using household apparatus

What each group will need

What you have to do

1. In your groups: plan how you are going to melt and solidify the substances.

2. Discuss the safety rules that you are going to apply.

3. Do the experiment and collect the data by completing the table.

4. What happen when solids are heated and cooled down?

Temperature

We have discovered that some substances melt very easy, while others need to be heated a while. Each substance melts at a certain temperature. Temperature is measured in degrees celsius (