I’ve understood that electrons move in a 3D field outside the nucleus and that they are quite far away from the nucleus itself (in relation to the atom scale).
What would happen if you pushed them out of this moving field of theirs, closer to the nucleus?
Is there a “spring” there then? Does the electron jump above its original orbit once you remove the external force and then oscillate a bit until it settles, or does it simply return to where it should be?
For a single electron, kind of. There’s no force acting on it outside of the attractive force between it and the nucleus, so it would just end up in an elliptical orbit, and if you just looked at the distance from center, it would appear to oscillate like a spring as it goes around.
This is misleading, though, because springs push and pull in both directions, and that’s not what’s happening here. What’s actually happening is something like Pluto’s orbit, where it’s closer than Neptune half the time and farther the other half, but nothing’s really making it do that besides geometry.
If you have other electrons, like in most atoms, now you get a repulsive force from the electrons, which are all in their own spherical shells, and they interfere with elliptical orbits enough that they eventually become spherical. This would look more like a spring eventually settling if you just look at distance from center.