Fick's law

Fick's law is a rule that tells us how fast things move from one place to another place. Imagine you have a cookie in a jar that you want to eat. You could just reach in and grab it, but that's not what Fick's law is about.

Fick's law is about something called diffusion, which is when tiny things move from one place to another because they're always jiggling around. Imagine if you had thousands of little balls bouncing around in the jar, and you wanted to know how fast they would all spread out into the air around the jar.

Fick's law tells us that the speed of diffusion depends on three things. First is how big the balls are. Big balls will move more slowly than small ones. Second is how much stuff there is in the jar. The more stuff there is, the more stuff the balls have to move through to get out. And third is how far away the air outside the jar is. If the air is very close, the balls won't have to move as far to get out, so they'll move more quickly.

So, to sum up, Fick's law is about how fast tiny things move from one place to another. We use it to figure out how quickly things like gas or water vapor will spread from one place to another, based on their size, how much stuff is in the way, and how far they have to travel.