Hey, I have a question for evaporation--What is the real driving reason for evaporation? I usually believe that it is a pure diffusion process: the saturated pressure of liquid at the liquid vapor interface is higher than the partial pressure of vapor in the ambient, and this pressure difference makes the liquid evaporate. However, I also know that evaporation absorbs heat. It looks like heat might be another driving force for evaporation. Think about this: although there is some pressure gradient, there is no heat supply to the liquid-vapor interface---then what will happen? The heat supply will limit the evaporation rate?