Student’s Book 2
1.5
Animals in different habitats
Animals live in habitats where they can find food, water and shelter. Some animals need special habitats. For example, fish need to live in water, and earthworms need soil because they live underground. The conditions in the environment affect which animals can live there. The photograph below shows a river that runs through a hot, dry and rocky environment.
water
shelter
frog
goat
bird
3.5 Hard or soft?
Scientists can group materials by looking at their properties. Materials with similar properties can be grouped together.
Look at these pictures. Some of the materials in the pictures are soft and some are hard.
1 Which materials are harder than the others?
2 Name some other hard materials. Name some other soft materials.
Look at the surfaces in these pictures.
3 Which surface is the hardest? Why does this surface need to be harder than the others?
4 Describe a way you could test which surface is the hardest.
4.3 Changing the shape of an object
Push down on a football or tennis ball. Observe the ball. What do you notice? The push force has changed the shape of the ball.
Forces can change the shape of some materials. You can squeeze a ball in your hand and it will change shape. You can stretch an elastic band and it will change shape. You can squash clay and it will change shape.
6.3 Rocks are useful
Rocks are very useful. If you look around you will see that rocks are used in buildings, to make statues and monuments, and to make roads and pathways. They are crushed to make cement and concrete, and polished to make jewellery and ornaments. The properties of a rock make it suitable for different jobs.
1 Find three different types of rock used in or around your school.
2 Why do you think each type of rock was chosen for the job it is doing? Talk about how you could find the answers to this question.
Slate is often used to tile the roofs of important buildings. Slate is hard and it splits into thin sheets. Water runs off it.
Granite and marble are often used to build statues or monuments. Both types of rock are attractive and can be polished to make them smooth and shiny.
Sandstone blocks are used to build walls. Sandstone is easy to cut and shape but it wears away fairly easily.
