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

Small bubbles of water boiling – but during this time not all water is 100° C so not all water is at boiling temperature. The little bubbles of steam travel up and the water above it at a bit lower temperature cools the steam down back to water, so they don’t escape from the top.