what is nuclear stability

Nuclear stability refers to the stability of a nucleus of an atom, which means that the nucleus of an element is stable and does not decay spontaneously emitting any kind of radioactivity. Among the approximately 9,000 nuclei expected to exist, and the approximately 3,000 presently known, only 195 are stable against spontaneous decay, because of energy conservation. The stable nuclei are gathered in the valley (or island) of Nuclear Stability in the chart of nuclides, which is a two-dimensional graph in which one axis represents the number of neutrons and the other represents the number of protons in an atomic nucleus. Nuclei that contain magic numbers of protons and neutrons are often especially stable/21%3A_Nuclear_Chemistry/21.02%3A_Patterns_of_Nuclear_Stability). The stability of an isotope can be determined by calculating the ratio of neutrons to protons present in a nucleus (N/Z) . Neutrons are important for stabilizing the nucleus because they attract each other and protons, which helps offset the electrical repulsion between protons. As a result, as the number of protons increases, an increasing ratio of neutrons to protons is needed to form a stable nucleus.