[Steely Tom]

why don’t negative electrons collapse into positive protons in the nucleus ?

The Pauli Exclusion Principle is, I believe, the main reason.

[Getready]

That characterizes the phenomenom...doesn’t really explain “why” based on your reference. They are called electron orbits..but do they orbit? Or just occupy a specific space under low energies a percentage of tbe time? Cheers....