Binding Energy per Nucleon
The average energy required to remove a single proton or neutron from an atomic nucleus, representing relative nuclear stability.
Governing formula
BE / A = Total Binding Energy / Mass Number
SI unit
MeV/nucleon
In depth
Binding energy per nucleon rises rapidly for light elements, peaks near Iron-56 and Nickel-62 (~8.8 MeV/nucleon), and gradually decreases for heavier elements. Fusing light elements or fissioning heavy elements moves nuclei toward the peak, releasing nuclear energy.
Examples in the real world
Explaining why energy is released during hydrogen fusion in stellar cores and uranium fission in nuclear power plants.