Many of the different materials you use day in, day out, can be changed by a change in the temperature.

Question is: what will happen to them?

Sometimes they melt, sometimes they boil, sometimes they freeze - in other words, they change state.

Substances can change from solids to liquids to gases, and back again!

Substances can also change permanently when they're heated - like a cake that's been baked.

You already know, from your experiences in life and from your science lessons, that some solids melt when heated. 

Some liquids boil when heated and turn to vapour (gas).

Similarly, when liquids are cooled down, some turn solid (in a process called 'freezing') and, amazingly, you can cool some gases down enough to turn them back into liquids (that's called 'condensing').

In this activity, we'll think about the materials in the questions and what we have learnt about them.

We'll then use that information to help to answer the questions on changes of state.

You ready to find out more?