Let and denote the magnitudes of the net force by a proton on a proton, by a proton on a neutron and by a neutron on a neutron respectively. Neglect gravitational force. When the separation is .
Two nucleons are at a separation of . The net force(nuclear) between them is if both are neutrons, if both are protons and if one is a proton and other is a neutron. In such a case,
Fusion processes, like combining two deuterons to form a nucleus are impossible at ordinary temperatures and pressure. The reasons for this can be traced to the fact:
