Consider the following three nuclear reactions:

Solution

In nuclear reactions, the energy released per nucleon depends on how much the binding energy per nucleon increases during the process. Let’s analyze the three processes using this concept: The binding energy per nucleon curve peaks around iron (Fe, A ≈ 56), which is the most stable nucleus. The energy per nucleon released in any nuclear reaction depends on how far the product nuclei move towards iron on this curve. • Heavy nuclei like uranium have lower binding energy per nucleon . • When uranium-235 undergoes fission, it splits into medium-mass nuclei (e.g., barium and krypton), which are closer to iron , thus releasing energy. • Energy per nucleon released is moderate , typically about 0.8 MeV per nucleon. II. Fusion of two deuterons • Light nuclei like deuterium (²H) have very low binding energy per nucleon. • Fusion to form helium or heavier light elements significantly increases the binding energy per nucleon. • This process releases the highest energy per nucleon , often up to 6–7 MeV per nucleon in some reactions • This is a slow and less energetic process , where uranium-238 emits a helium nucleus (alpha particle). • The energy released is small , usually a few MeV total , not significant per nucleon compared to fission or fusion. Among the three, fusion of deuterons releases the maximum energy per nucleon , as it moves light nuclei significantly up the binding energy curve.