/ It was very simple answer/ In fact,nucleons act reciprocally by the nuclear field which consists of virtual п-mezons,really - nucleons are surrounded a mesonic "fur coat". And between nucleons operate only nuclear forces(every nucleon has a constant of strong co-operations, which determines the size of nuclear forces) . Electric charge does not influence on them. There is charge's independence of nuclear forces. If we examined these forces, as electromagnetic, protons would push off and destroy a nucleous.Nuclear forces in one hundred times exceed electromagnetic forces and have short- active character
there are many types nucleons but we consider only two nucleons. protons and neutrons.
Protons have positive charge and Neutrons have no charge.
the reason for the repulsion forces between the nucleons is
the same charged particles always repel as the north pole of one magnet and north pole of other magnet repel in the same way the proton and proton repel in side the nucleus and neutrons does not have repulsion force.