Why does boiling water create bubbles in a pot? Was the water not already taking up the space?

Question

Why does boiling water create bubbles in a pot? Was the water not already taking up the space?

In: Physics

Answer 1

Those bubbles are water vapor, steam. Since heat is applied at the bottom of the pot, that’s the hottest part, and where water evaporates into steam the quickest.

There can also be gases dissolved into the water, like the CO2 disolved in your soda, but typically these are quite small amounts.