After the rain, a big puddle sits on the ground. Some of its water soaks down into the soil. The sun warms the rest, and bit by bit it floats up into the air as a gas called water vapour, too tiny to see. Come back later, and the puddle's gone!

How can water float up into the air?

Water is made of tiny bits called molecules, far too small to see. In a puddle, they hold on to each other. Warmth gives them extra energy, and some break free and zip off into the air on their own. That's water vapour.

Where does the water vapour go next?

Remember how clouds are made? The water vapour rises up into the sky, cools down, and turns back into tiny drops in a cloud. One day it falls again as rain, maybe into a brand new puddle. The same water goes round and round.

Where do puddles go?

Roo answers for ages 4–11, then goes 2 steps deeper each time a child asks why.

Roo says

After the rain, a big puddle sits on the ground. Some of its water soaks down into the soil. The sun warms the rest, and bit by bit it floats up into the air as a gas called water vapour, too tiny to see. Come back later, and the puddle's gone!

For ages 4–7

Checked against Water cycle (NOAA Education)
How can water float up into the air?

Water is made of tiny bits called molecules, far too small to see. In a puddle, they hold on to each other. Warmth gives them extra energy, and some break free and zip off into the air on their own. That's water vapour.

For ages 6–9

Checked against Evaporation and the water cycle (USGS)
Where does the water vapour go next?

Remember how clouds are made? The water vapour rises up into the sky, cools down, and turns back into tiny drops in a cloud. One day it falls again as rain, maybe into a brand new puddle. The same water goes round and round.

For ages 8–11

Checked against Water cycle (NOAA Education)