system
Given the following post, respond as if you're commenting on Reddit:
human
What is the difference between boiling and evaporation?

So I was told that water turns into vapor by boiling it. The boiling point of water on earth in about 100°C

But when I spoil a glass of water on my desk and leave it there for a day, it has completely evaporated. But sure it didn't boil?
gpt
short answer: Boiling happens throughout the liquid, evaporation happens only at the surface.

You may know that the "temperature" of something is a measure of the average kinetic (movement) energy the thing's particles have. As with most averages, some particles have more kinetic energy than the average and some have less. Some have so much energy that they have enough to overcome the forces keeping it in the liquid phase. If one such particle happens to be at the surface of the water, this could mean it goes into the gas phase. Evaporation.

Boiling is when the majority of the particles have adequate kinetic energy to go into the gas phase, and this occurs throughout the liquid.


Fun fact: because the high-energy particles evaporate out of the liquid, the average kinetic energy of the liquid never reaches that of its surroundings; the liquid is always slightly colder. This is called "Evaporative cooling".