How does water evapourate at room temperature?
Very good question. The answer is the the average temperature of a puddle of water is room temperature (or air temperature or whatever), but each individual molecule is NOT at that temperature. So if the average temperature of a puddle is 18degrees, maybe one in every hundred molecules will be at 100degrees. This molecule will then evaporate, leaving the average temperature of the water slightly lower. The water is, of course, surrounded by air. Both the water and the air get heated by the sun (and the water gets heated by the air), so the puddle goes back up to 18degrees, and another particle will get warm enough to evaporate.
