The Properties of Materials
≈ 15 minA property is a word that describes what a material is like. Materials can be:
- hard or soft;
- strong or weak;
- flexible (bendy) or stiff;
- rough or smooth;
- transparent (see-through) or opaque (not see-through);
- waterproof or absorbent (soaks up water).
We find a material's properties by testing it. Press it — is it hard or soft? Try to bend it — flexible or stiff? Pour a little water on it — waterproof or absorbent? Hold it up to the light — transparent or opaque?
Worked example. Why is a raincoat made of plastic and not paper?
Plastic is waterproof and flexible, so the rain runs off and you can still bend and move. Paper is absorbent — it soaks up water and quickly falls apart. The property 'waterproof' is what makes plastic the right choice.
Glass lets you see straight through it. Which property word means 'see-through'?
A rubber band and a metal spring are useful because they can bend and then spring back. Which property is this?
A raincoat keeps you dry because rain cannot pass through the plastic. What property is this?
A sponge soaks up water instead of letting it run off. Is a sponge waterproof or absorbent?