Hi Guys Can somebody explain me why does all protons be at nucleus of a atom only ..
..I once read that same charges repel so which force or phenomena breaks such a simple law??

This is a great question. The positive charge of each proton should push away other nearby protons. So a nucleus with more than one proton doesn't seem possible, at the surface level. However, there's the strong nuclear force that is tying together these protons along with neutrons to form nuclei. Of the four fundamental forces, this has the most strength, but the shortest amount of range. This means the protons and neutrons must be really close together for this force to be effective.

force tends to be low and long diustance masses are high