Water can exist in three different forms, and you’re probably familiar with a couple of them. The one we usually think of is liquid water. That’s the kind we drink! Water can also be solid when it is in the form of ice or snow. The third form isn’t as easy to see because it’s actually an invisible gas that is in the air. You’re breathing some in right now!
When liquid water gets enough energy, often from heat, it gets very excited and escapes into the air! You’ve probably seen water’s escape act when a grown-up boils water in a teakettle. When it’s hot enough, you hear a whistle caused by steam. Steam is made up of mostly water vapor, but there’s also some liquid water in it that gives it a slight white color that we are able see.
Water vapor is very important to the environment because without it, we wouldn’t have rain or clouds! When water vapor cools in the sky, it becomes a liquid again. That liquid water forms the clouds that will soon rain down to the ground!