This Kapow pupil video is part of the Kapow Science scheme of work. A reversible change is when a material can be changed back to its original form. It’s a change that can be undone. For example, if you mix soil and gold nuggets, you can separate them again using a sieve – that’s a reversible change.

Mixing water with coffee granules is another reversible change. A filter can separate the large coffee bits from the water. But what about the coffee-flavoured water that passes through the filter? That might seem irreversible, but it’s not. When something dissolves, like coffee or salt in water, it can still be reversed. By gently heating the mixture and letting the water evaporate, the solid is left behind in crystal form. So even when something looks like it’s gone – it might not be!

The video is designed to be shown to pupils as part of Science, key stage 2, Year 5, Materials: Properties and changes, Lesson 4: Reversible changes