Answer:
The stability of isotopes is affected by the ratio of protons to neutrons and also by the presence of certain “magic” numbers of protons or neutrons that represent closed and filled quantum shells. These quantum shells correspond to the shell model of the nucleus. Filled shells confer unusual stability on a nuclide. A magic number for the atomic number (with filled shells) tends to increase the number of stable isotopes of an element.
Explanation:
