What is vapor?

Vapor is like invisible water that’s pretending to be air.

Imagine you're taking a hot shower. The steam that rises from the shower is vapor, it's just water that has gotten so hot, it turned into a gas and floated up to meet the cooler air above. That’s what happens with vapor: liquid water turns into gas, and we can see it when it moves around or mixes with other air.

When you blow on your soup to cool it down, sometimes you see little clouds in front of your mouth, that's vapor too! The warm breath you're blowing out has water vapor in it. When the warm vapor hits the cooler air around it, some of that water turns back into tiny drops of liquid, making those little clouds.

Vapor is all around us:

• In a steamy bathroom after a shower
• Coming off your hot coffee
• Making fog on cold mornings

So next time you see steam or fog, remember, it’s just water having fun as vapor!