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?
I’m no expert, but I found this. An electron entering the nucleous and interacting with a proton is called electron capture. The proton and electron are converted into a neutron and an electron neutrino. The wiki article says this is a form of radioactive decay.