system
Given the following post, respond as if you're commenting on Reddit:
human
What happens if two electrons collide when they are orbiting a nucleus?

Just researching Cosmos. It got me thinking. As electrons orbit an atoms nucleus, what would happen if two of the electrons collided?
gpt
I imagine you're picturing the nucleus as the sun and the electrons as planetary balls literally orbiting it? And a collision being two electrons' trajectories crossing? 


This picture isn't really accurate. The electrons are not literally orbiting the nucleus with circular trajectories, and the electrons are not small balls. The electrons are dimensionless entities kinda smeared out as a wave over a region, and the shape/size of that region around an atom is the orbital, or state. The regions of each electrons' state can and do overlap with each other, and the nucleus at sometimes, but this isn't them colliding in any way.


As such, the notion of them having orbital trajectories that collide doesn't make any sense. The electrons certainly interact with each other. The charge of the inner ones shield the outer ones from the nucleus charge, and an electrons prevent any other electron from moving into their state. And in other situations, like say a free electron traveling, electrons can scatter off each other. But around the nucleus electrons in different states colliding or scattering off each other is not something that occurs.