Question

How is evaporation related to humidity?

Answer 1

Well, the rate of course...

Explanation:

I'd say that the rate of evaporation is inversely proportional to the rate of humidity. This is because humid air contains lots and lots of water molecules, therefore forming a region of higher concentration. When water evaporates, the water molecules want to move away from each other and into the air, but since there is a region of higher concentration there, it is unlikely that they'll try to "fit into" that area. That's because of diffusion.

Diffusion states that molecules will move down a concentration gradient to maximize equilibrium between two sides.

I hope this helps, otherwise check these answers:

https://www.quora.com/How-does-humidity-affect-evaporation