Short answer
In warmth, ice particles can move more freely - the ice melts. When they freeze, they are held in place again.
Ice is also water
Ice and water are made up of the same tiny particles. They are so small that you cannot see them with your eyes. These particles attract each other.
In ice, the particles stay in place and only tremble a little. Imagine children in a tight round dance. Therefore, the piece of ice retains its shape.
In liquid water, particles can move past their neighbors. That's why water flows. If you pour it into a glass, it will take its shape.
See it for yourself
Warm the ice, then freeze the water again
Open experiment ↗What happens in the heat?
Let's warm up the ice. Heat helps its particles break out of strict order. Now they can move past each other.
This is how solid ice becomes liquid water. The particles remained the same. The way they hold together and move has changed.
The ice becomes smaller, and there is more water nearby. This means that the ice does not disappear - it melts. See how it goes.
Is it possible to return the ice?
Now let’s cool the water very much. It gives off heat and its tiny particles move more slowly.
When water freezes, the particles line up again and hold each other in place. It turns out to be a hard piece of ice.
This is how a freezer works: it takes heat from the water. In our experience, everything happens quickly. In life, ice cubes need more time.
What is simplified in the model
On the screen the ice melts and the water freezes faster than in real life.
For adults · discuss together
On the screen the ice melts and the water freezes faster than in real life.
Before experience
Ask: “What do you think will happen?” Let the child check his guess first.
After the experience
What has changed? What remains the same? Where can you notice a similar phenomenon?
