Boiling

Most recent answer: 10/22/2007

Q:
what causes boiling
- Kate (age 11)
Laural,MD,U.S
A:
Say you have some liquid like water. Sometimes water molecules get enough energy to jump right out of the liquid into the gas above it. The hotter the water gets, the more often that happens. If the gas is ordinary air, those molecules usually drift off among the air molecules, so the water gradually evaporates. If the water gets hot enough, then even for a little bubble inside the liquid, the water molecules leave the liquid faster than molecules leave the gas and rejoin the liquid. So the little bubble will grow, filling up with water vapor. That’s what we call boiling.

Mike W.

(published on 10/22/2007)