Two protons can exist together in the nucleus of an atom because their electrostatic repulsion is overcome by what forces?
Because of the
You will probably get a much better answer in the Physics section, because the strong nuclear force is something about which most chemists (and me) don't have much of an idea.
At nuclear ranges (apparently!), electrostatic repulsion is superseded by a close range attractive force that operates between protons and neutrons that serves to binds the nucleons together, and keeps the nucleus stable.
By the way, if there are 2 protons in the nucleus, then what is the element?