Ha! This one is easy for me! Okay... So when water freezes, it expands, and turns into a semi-solid. It is only temporary, as the cold stiffens it to a great degree. Now, when something is melting, its molecules are retracting, and it is getting warmer. So if you set a ice cube on a table, the molecules will retract, and the ice cube will melt :) Hope I could help :)