bindingsenergi

Binding energy is the energy required to separate a bound system into its individual components, or equivalently the energy released when the components come together to form the bound state. It is a measure of the stability of the system.

In nuclear physics, the binding energy of a nucleus with Z protons and N neutrons (A = Z + N) is related to the mass defect: Δm = Z m_p + N m_n − M_nucleus, and E_b = Δm c^2. The binding energy per nucleon, E_b/A, indicates how tightly each nucleon is bound. For example, deuterium binds with about 2.22 MeV total, helium-4 about 28.3 MeV, and the maximum binding energy per nucleon occurs near iron-56 at roughly 8.8 MeV. This peak explains why energy is released in both fusion of light nuclei and fission of heavy nuclei, as reactions move toward higher binding-energy per nucleon.

In chemistry, binding energy refers to the energy required to break a chemical bond, often called bond dissociation energy. It is typically expressed per bond in units such as kilojoules per mole (kJ/mol). Common values include about 436 kJ/mol for H2 and about 498 kJ/mol for O2, though exact values depend on molecular context and environment.

Binding energy can be inferred from mass measurements in spectroscopy or inferred from reaction energetics in chemistry. It plays a central role in understanding nuclear stability, stellar processes, and the energetics of chemical reactions and phase transitions.