All atomic nuclei are composed of protons and neutrons bound together by the nuclear force. There are 286 primordial nuclides … See more

The protons and neutrons that comprise an atomic nucleus behave almost identically within the nucleus. The approximate symmetry of isospin treats these particles as identical, but in a different quantum state. This symm… See more

The mass of an atomic nucleus is given by
where and are the rest mass of a proton and a neutron, respectively, and is the total binding energy of the nucleus. The mass–energy equivalence is used here. The binding ene… See more

The boundaries of the valley of stability, that is, the upper limits of the valley walls, are the neutron drip line on the neutron-rich side, and the proton drip line on the proton-rich side. The nucleon drip lines are at the extremes o… See more

The island of stability is a region outside the valley of stability where it is predicted that a set of heavy isotopes with near magic numbers of protons and neutrons will locally reverse the trend of decreasing stability in elements h… See more

The valley of stability can be helpful in interpreting and understanding properties of nuclear decay processes such as decay chains and nuclear fission.
Radioactive decay often proceeds via a sequence o… See more