system
Given the following post, respond as if you're commenting on Reddit:
human
When I hit my hand against a wall, what exactly is stopping my hand from going through the wall?

I know it sounds like a stupid question.

When you're looking at it on an atomic level, what makes atoms (or nuclei) unable to intersect with one another? Why are some subatomic particles able to intersect, but not atomic particles?
gpt
It's the force of the electrons in your hand repelling the electrons in the wall. The closer your hand gets, the larger that force gets; due to the inverse square dependence of electrostatic forces, you don't notice it until you're pressed right up against it.