Question

What is boiling? Explain it on the basis of molecular motion.

Answer 1

The change from liquid state to gaseous state, on heating at a constant temperature is known as boiling. ​
Explanation:​ The kinetic energy of molecules determines the molecular motion. On heating, the kinetic energy of molecules of liquid increases.​ After acquiring kinetic energy, these molecules are able to overcome the attractive force of other molecules. Hence, they start escaping from the bulk of liquid. This is shown by the appearance of bubbles in liquid. This bubbles grow in size and move to the surface in quick succession. This causes an agitation in whole of the liquid, and it is called boiling.