Question: how does water evaporate into steam or clouds

Jake Langham answered on 28 Nov 2017:

In a glass of water the molecules are all moving around randomly at different speeds. Because it is random, some will be going fast and some slow. Sometimes the fast molecules have enough energy to leave the glass and become a gas called water vapour. In warmer water, evaporation happens quicker because the molecules are moving faster, on average (they have more energy). When you boil water, it changes to steam very fast but really the same thing is happening as if you just let a cup of water out in the sun all day. Hope that answers your question 🙂