Physics
Physics
Problem
Consider the following two idealised energy-producing nuclear processes. a. Process A: One ²³⁸U nucleus (binding energy per nucleon 7.6 MeV) splits into two equal fragments of A = 119, each having binding energy per nucleon 8.5 MeV. b. Process B: Four ⁴He nuclei (binding energy per nucleon 7.1 MeV) fuse to form one ¹⁶O nucleus (binding energy per nucleon 7.98 MeV). c. (i) Derive an expression for the energy released per nucleon in terms of the initial and final binding energies for any nuclear reaction of this type. d. (ii) Using the numerical values supplied, calculate the total energy released per event for Process A and for Process B (in MeV). e. (iii) Convert both energies to kilojoules per mole of original reactant nuclei and identify which process yields more energy per mole. f. (iv) Based on your calculations, explain why heavy elements are suitable for fission power reactors while light elements are favoured for fusion power schemes.Intuitive explanation
These two processes—fission and fusion—release energy by converting mass into energy via , but they work in opposite directions on the binding energy curve. The key insight is that both move nuclei toward iron-56 (the most stable nucleus), so comparing their mass defects tells you which process releases more energy per nucleon and why nature favors each in different regimes.
Intuitive explanation
These two processes—fission and fusion—release energy by converting mass into energy via , but they work in opposite directions on the binding energy curve. The key insight is that both move nuclei toward iron-56 (the most stable nucleus), so comparing their mass defects tells you which process releases more energy per nucleon and why nature favors each in different regimes.