Question

Draw a graph showing the variation of binding energy per nucleon with mass number of different nuclei. Mark the region where the nuclei are (a) most stable, (b) prone to fusion and (c) prone to fission.

Answer 1

Hint: Binding energy is the amount of energy required to disintegrate a system, which means to remove a particle from a system of particles. The amount of energy released during the formation of a nucleus from its component nucleons is known as the nuclear binding energy.

Complete step by step answer:

Greater the nuclear binding energy; more the stability of the resulting nucleus. Conversely, elements with high binding energy are difficult to break up owing to their stability.
The region in blue (roughly including elements from atomic mass 50 to 80) marks the most stable nuclei. It must be noted here that Iron (mass number 56) has the highest binding energy. The region shaded in orange (to the left of the blue region) marks the nuclei that are most prone to fusion. Fusion is generally achieved by combining deuterium and tritium, two isotopes of hydrogen. On the other hand. The region shaded in yellow marks the nuclei most prone to fission. Several heavy elements including uranium, thorium and plutonium undergo spontaneous as well as induced fission.

Note: Binding energy is expressed in MeV per nucleon; the average binding energy being 8MeV if we don’t include the lighter nuclei. Binding energy curve serves two main purposes: it suggests how stable atomic nuclei are and it also suggests possibilities of converting a significant amount of mass into energy.