Two protons are brought towards each other. Will the potential energy of the system decrease or increase? If a proton and an electron be brought nearer, then?

The potential energy when two protons are brought closer and the potential energy ---------------when one proton and one electron are brought close together.

In bringing an electron towards another electron, the electrostatic potential energy of the system

Two protons attract each other when

In a hydrogen atom, the electron and proton are bound together at a distance of above 0.53 Å. Estimate the potential energy of the system in eV, assuming zero potential energy at infinite separation between the electron and the proton.

In a hydrogen atom, the electron and proton are bound at a distance of about 0.53 Å: (a) Estimate the potential energy of the system in eV, taking the zero of the potential energy at infinite separation of the electron from proton. (b) What is the minimum work required to free the electron, given that its kinetic energy in the orbit is half the magnitude of potential energy obtained in (a)? (c) What are the answers to (a) and (b) above if the zero of potential energy is taken at 1.06 Å separation?