Unit 8 Bubbles in Boiling Water

Where do the bubbles come from when you boil water?

Water is a liquid.

When it is heated, it moves around faster and faster. When it starts to boil, the liquid turns into a gas. This gas is called water vapor. This gas is lighter than the water around it. It rises to the top. Then it disappears into the air. As the water gets hotter and hotter, it starts turning into gas very quickly.

A lot of bubbles form at the same time. All these bubbles try to escape at once. The bubbles push the water out of the way and “jump” out. This is what we call “boiling water.” More and more water turns into gas.

More of it disappears into the air. After a while, every drop of the water will be gone. Try it and see!