Question

Draw a graph showing the variation of binding energy per nucleon as a function of mass number A. The binding energy per nucleon for heavy nuclei (A > 170) decreases with increase in mass number. Explain its significance.

Answer 1

1. Heavy nuclei are less tightly bound compared to mid-mass nuclei.
2. The binding energy per nucleon decreases because the repulsive Coulomb force between protons becomes significant.
3. This explains nuclear fission: heavy nuclei can split into smaller nuclei with higher binding energy per nucleon, releasing energy.
4. It is the basis of nuclear reactors and atomic bombs.