Nuclear stability and binding energy
Nuclear Chemistry · Chemistry
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Helium-4 nucleus mass = 4.0015 u; 2 protons (1.0073 u each) + 2 neutrons (1.0087 u each). Find binding energy. Step 1: Sum of parts = 2(1.0073) + 2(1.0087) = 4.0320 u. Step 2: Δm = 4.0320 - 4.0015 = 0.0305 u. Step 3: E = 0.0305 × 931.5 MeV/u ≈ 28.4 MeV. Step 4: Per nucleon: 28.4/4 = 7.1 MeV — the 'missing mass' became binding energy!