Question

give an example to understand the expansion in solids

Answer 1

The same happens in all liquids and gases, driving natural heat transfer upwards in homes, oceans, and weather systems. Solids also undergo thermal expansion. Railroad tracks and bridges, for example, have expansion joints to allow them to freely expand and contract with temperature changes.
Thermal Expansion of So

Answer 2

Water → ice

Explanation:

Water, being one of the only substances found here on Earth that can exist in the three natural states from normal pressure, freezes and boils at relatively normal/sustainable temperatures that can be achieved in a normal environment.

When water freezes, it's particles contract (when being frozen), and then slightly expand → this is one example.

However, when water is boiled, it's particles expand quickly depending on the temperature.