Two identical light nuclei each have mass number 3 and binding energy per nucleon 2.5 MeV. They fuse into one nucleus of mass number 6 whose binding energy per nucleon is 5.5 MeV. If the energy released is N MeV, find N.
Physics · Nuclear physics · nuclear fission and fusion ,nuclear reactor
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Question

Two identical light nuclei each have mass number 3 and binding energy per nucleon 2.5 MeV. They fuse into one nucleus of mass number 6 whose binding energy per nucleon is 5.5 MeV. If the energy released is N MeV, find N.

Physics · Nuclear physics · nuclear fission and fusion ,nuclear reactor

G1 Physics · Accepted Answer

Initial binding energy of one light nucleus: BE(one) = 3×2.5 = 7.5 MeV. For two nuclei: BE(initial) = 2×7.5 = 15 MeV. Final binding energy: BE(final) = 6×5.5 = 33 MeV. The released energy equals the increase in total binding energy: Q = BE(final)−BE(initial) = 33−15 = 18 MeV. Hence N = 18.