Evaporation occurs when the molecules at the surface of a liquid gain enough to overcome the of other molecules in the liquid phase.

Evaporation occurs when the molecules at the surface of a liquid gain enough energy to overcome the force of attraction of other molecules in the liquid phase.
When a molecule of a liquid near the surface absorbs enough energy to overcome the vapor pressure, that molecule will escape from liquid and get in the surrounding air as a gas.

Ions gain or lose electrons