Question

Explain in terms of molecules what happens when
(a) ice changes to water.
(b) liquid wax solidfies after cooling.

Answer 1

(a) When ice changes to water, the water molecules, which was at a fixed position in the ice crystal, start to move around each other.

(b) Initially, liquid wax molecules are free to move around; hence, it flows. But after cooling, it solidifies and its molecules become immobile, i.e., fixed at a specific position.