What is the electrostatic potential energy (in joules) between an electron and a proton that are separated by 63 pm?

I copied the answer of NCS.

I just want you change it.

1.60218e-19 = 1 ev

EPE = kQq / d

EPE = 8.99e9N·m²/C² * -(1.6e-19C)² / 63e-9m = -3.65e-21 J

but you might not need the sign in your answer.

In terms of ev, it is easier remember.

3.65*10(-21)/(1.6*10^(-19))=2.28*10^(-2)eV

Just do the calculations

I'm not sure that the normal electrostatic potential between charged objects applies here, over such small distances. That's about the Bohr radius of a hydrogen atom, and clearly, the electron is not going to fall into the nucleus of a single proton.

Maybe you could determine from the radius what state of excitement the atom is in, and figure what energy would be released when the electron falls back into the ground state.