Answer to Question #145925 in Atomic and Nuclear Physics for Arsam

Question

Discuss graphically the variation of average binding energy per nucleon with A. Also explain
the stability of the nucleus on the basis of this concept.

Answer 1

The graph shows the binding energy per nucleon. This quantity is the average energy required to remove an individual nucleon from a nucleus—analogous to the ionization energy of an electron in an atom. The more binding energy nucleus has, the more stable it is because it is harder to break up the nucleus. Elements with A=56 (Fe and Ni) have the biggest binding energy per nucleon. This mean that they are the most tightly bound nuclei, therefore, very stable.

For elements below Iron-56 (Fe) the joining together of atoms produces nuclei with higher binding energy per nucleon producing energy. This is called nuclear fusion. For elements larger than Iron, which are split into two new smaller nuclei, the binding energy per nucleon is greater than the average binding energy, again releasing energy. This is called nuclear fission.