Their are three states of matter. Solid, liquid, and gas. When water is in solid form the molecules are tightly packed together. When the air gets warm enough the solid (ice cube) starts to melt into a liquid (water). When the air gets really hot the water starts to evaporate and turn into water vapor. After that, the water molecules in the air keep on rising and rising and start to combine together to create clouds. When enough of the molecules combine together the cloud gets to big and it starts to rain and the water cycle starts all over again.