Question

Define 'Mass defect' and 'Binding energy' of a nucleus. Describe the 'Fission process' on the basis of binding energy per nucleon.

Hint:

In nuclear fission, the binding energy per nucleon increases for lighter nuclei, which is why energy is released during fission of heavy nuclei.

Answer 1

Mass Defect: The mass defect of a nucleus is the difference between the total mass of its constituent nucleons (protons and neutrons) and the actual mass of the nucleus. The missing mass is converted into binding energy, which holds the nucleus together.

Binding Energy: The binding energy of a nucleus is the energy required to separate the nucleus into its individual nucleons. It is the energy equivalent of the mass defect.

Fission Process: In the fission process, a heavy nucleus splits into two smaller nuclei along with the release of energy. This occurs because the binding energy per nucleon of the smaller nuclei is greater than that of the original nucleus. The energy released in fission is due to the difference in binding energy per nucleon before and after the fission.

Thus, in fission, the total binding energy of the fragments after splitting is greater than the binding energy of the original nucleus, and this difference is released as energy.