Nuclear binding energy
The energy required to completely separate a nucleus into individual protons and neutrons. Equivalently, the energy released when protons and neutrons combine to form a nucleus. Related to mass defect by Einstein's mass-energy equivalence: ΔE = Δmc², where Δm is the difference between the nucleus's actual mass and the sum of constituent nucleon masses. Binding energy per nucleon (BE/A) is a measure of nuclear stability.
Formula
ΔE = Δmc²
Real World
Iron-56 has the highest binding energy per nucleon (~8.8 MeV), which is why stars like our Sun can only release energy by fusing lighter elements up to iron — beyond iron, fusion consumes energy rather than releasing it.
Exam Focus
Convert mass defect to kg before multiplying by c² — working in atomic mass units without conversion is the most common calculation error.
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