A liquid is in equilibrium with its vapour at its boiling point. On the average the molecules in the two phases have equal

Liquid is in equilibrium with its vapour phase at its boiling point.This means that the rate at which liquid molecules escape from liquid state or liquid surface to the gaseous state and the rate at which gaseous molecules strikes the surface of liquid and becomes liquid are equal. Rates are equal.In some time both molecules on both sides travel equal rate. These molecules have equal energy.Also potential energy of both molecules are not equal as molecule in liquid and in gas have different portions.Molecules have same kinetic energy.