A vapour is said to be saturated when?

A. a dynamic equilibrium exists between liquid molecules and the vapour molecules
B. a dynamic equilibrium exists such that more molecules return to the liquid than are living it
C. the temperature of the vapour varies
D. the vapour pressure is atmospheric

Correct Answer:

Option A – a dynamic equilibrium exists between liquid molecules and the vapour molecules

Explanation

A saturated vapour is one which is in dynamic equilibrium with its own liquid; that is as many go from the liquid to the vapour state every second return back to liquid.