So you know your bucket of Lego? It’s a bunch of blocks that can move around each other. (Swish some around to demonstrate)

Water is made up of little tiny block that can swish around too. When you make them cold, they start to stick together. (Start connecting Lego blocks)

The colder it is, the more they connect, until all the water blocks have joined up together and made a bigger block of ice.

Then, when you heat the ice up, they start to come apart and move freely again.

So, heat is movement and cold is connected. This is the same for almost everything!

Lava from volcanos is just rocks that have been heated up enough to move. When the lava flows out and cools down, it hardens back into rocks.