When you’re boiling a pot of water, right before the water starts to boil if you watch carefully at the bottom of the pot there will be tiny bubbles that form and disappear. Why do they just disappear instead of floating up to the top once they’re already formed??

Question

When you’re boiling a pot of water, right before the water starts to boil if you watch carefully at the bottom of the pot there will be tiny bubbles that form and disappear. Why do they just disappear instead of floating up to the top once they’re already formed??

In: Physics

Answer 1

Interestingly, if you use cold water and watch as it slowly heats up, you will see bubbles form that DO make it to the top.

Air dissolves more easily in cold water. As it heats up, the air has to come out. These bubbles will often sit on the bottom of the pot until they’re big enough and float to the top. Typically they are all gone by the time steam actually starts to develop (the disappearing bubbles).