Even and odd atomic nuclei abundant isotopes of their element, the former only by a small margin, and the latter only because the expected beryllium-8 has lower binding energy than two alpha particles and therefore immediately alpha decays. Actinides with odd neutron number are generally fissile (with thermal neutrons), while those with even neutron number are generally not, though they are fissionable with fast neutrons. Only , and have odd neutron number and are the most naturally abundant isotope of their element. Even and odd atomic nuclei In nuclear physics, properties of a nucleus depend on evenness or oddness of its atomic number "Z", neutron
Even and odd atomic nuclei Even and odd atomic nuclei In nuclear physics, properties of a nucleus depend on evenness or oddness of its atomic number "Z", neutron number "N" and, consequently, of their sum, the mass number "A". Most notably, oddness of both "Z" and "N" tends to lower the nuclear binding energy, making odd nuclei, generally, less stable. This effect is not only experimentally observed, but is included to the semi-empirical mass formula and explained by some other nuclear models, such as nuclear shell model. This remarkable difference of nuclear binding energy between neighbouring nuclei, especially of odd-"A" isobars, has important consequences for