Energy Released In Nuclear Fission

Energy is released in fission because the fragments are more tightly bound than the parent, so the total binding energy increases and the surplus appears as kinetic energy. The energy released equals the rise in binding energy per nucleon multiplied by the number of nucleons: $E=(BE/A{)}_{\text{fragments}}\times A-(BE/A{)}_{\text{parent}}\times A=(8.5-7.6)\times 240$. Evaluating, $E=0.9\times 240=216$ MeV. The value 16 MeV ignores the mass number and merely multiplies the difference by a small factor. The value 432 MeV doubles the result, perhaps by counting each fragment's nucleons twice. The value 0.9 MeV is just the per-nucleon binding-energy increase and forgets to multiply by the 240 nucleons. The liberated energy appears mostly as kinetic energy of the two fragments, which fly apart under their mutual Coulomb repulsion, with smaller contributions carried off by emitted neutrons and gamma radiation. This matches the NCERT explanation of why fission of heavy nuclei releases roughly 200 MeV. A plausibility check confirms the answer is close to the well-known ~200 MeV released per uranium fission, consistent with a mass-240 nucleus splitting near the curve's descending side.