- Define and explain Describing Materials in your own words
- Use key terms such as property accurately
- Apply what you have learned to new examples and questions
- Avoid the common mistakes learners make with this topic
Look around your classroom: wood, plastic, glass, fabric and metal are everywhere. Scientists sort materials by their properties — what they look, feel and behave like. In this chapter you will describe, test and group materials, and learn how the right choice of material makes everyday objects work.
This lesson focuses on Describing Materials: learn words like hard, smooth and stretchy to describe what materials are like.
Learn words like hard, smooth and stretchy to describe what materials are like.
Key ideas
Properties you can observe
You can find out a lot about a material using your senses: sight, touch and sometimes sound. Is it shiny or dull, smooth or rough, bendy or stiff, heavy or light? Scientists record these observations carefully before they sort anything, because good sorting starts with careful looking. Try describing five objects in the room and compare your words with a friend.
Sorting by one property
When you sort materials, pick just one property at a time, for example magnetic or not magnetic. A fridge magnet sticks to steel but not to plastic, wood or glass, so steel goes in one group and the others go in another. Using one rule keeps the groups fair and makes the pattern easy to see.
Key term — property: Something you can observe about a material, for example whether it is hard, shiny, rough or stretchy.
Suggest a material for a playground slide and explain your choice using two properties.
Plastic is a good choice because it is smooth, so children slide easily, and waterproof, so rain does not damage it. Other sensible answers with two properties are acceptable.
Answer: Plastic is a good choice because it is smooth, so children slide easily, and waterproof, so rain does not damage it. Other sensible answers with two properties are acceptable.
- Sorting by colour alone Colour is a poor sorting rule because many different materials can be the same colour. Sort by a property that tells you something useful, like hardness or waterproofness.
- Putting an object in two groups at once When you sort by one rule, each object belongs in exactly one group. If an object seems to fit both, your rule may need to be clearer — for example rough or smooth, not a bit of both.
Practice
Glass, because it is transparent so light can pass through and you can see through it.
Any two sensible properties, for example whether they are magnetic and whether they are waterproof (metal versus wood).
It is waterproof, so rain cannot soak through it.
False. Iron and steel are magnetic, but metals such as copper and aluminium are not.
Quick check
Which of these best defines "property"?
You sort buttons into shiny and dull. Why is this a fair sorting rule?
- Describing Materials: learn words like hard, smooth and stretchy to describe what materials are like.
- Properties you can observe: You can find out a lot about a material using your senses: sight, touch and sometimes sound.
- material: Anything things are made from, such as wood, plastic, glass, fabric or metal.
- Watch out for: sorting by colour alone