Consider the case where there's a head on collision between the two( impact parameter=0) giving the electron no reason to orbit around the proton. What sort of bound state would be formed then?
I mentioned coulomb attraction for unlike charges. Say, if two unlike charges were held at a distance away from each other and then left to themselves what would happen after they get very close to each other?
Can charges collapse under coulomb attraction like charge-less matter does under gravity? In a way it's similar to asking about the lower limit of coulomb force if there is any. Also, does Pauli exclusion principle save the day just as in the case of gravity?