Binding Energy Definition in Science

What Is Binding Energy in Science?

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In physics, binding energy is the minimum energy required to either separate an electron from an atom or to separate the protons and neutrons of an atomic nucleus. It is equal to the mass defect less the quantity of energy or mass released when a bound system is created. Binding energy is also known as separation energy.

Types of Binding Energy

There are several types of binding energy. These include:

  • Atomic Binding Energy: The atomic binding energy is the energy needed to break an atom into its nucleus and free electrons.
  • Bond Dissociation Energy: Bond dissociation energy is the binding energy between atoms that share a chemical bond. It is a measure of the energy needed to break a molecule into its atoms.
  • Ionization Energy: Ionization energy is the energy required to break electrons from their orbits around atoms.
  • Nuclear Binding Energy: Nuclear binding energy is the energy required to break a nucleus into free protons and neutrons. It is the energy equivalent of the mass defect.


  • Bodansky, David (2005). Nuclear Energy: Principles, Practices, and Prospects (2nd ed.). New York: Springer Science + Business Media, LLC. ISBN 9780387269313.
  • IUPAC (1997). Compendium of Chemical Terminology (2nd ed.) (the "Gold Book"). Compiled by A. D. McNaught and A. Wilkinson. Blackwell Scientific Publications, Oxford. ISBN 0-9678550-9-8.
  • Wong, Samuel S.M. (2004). Introductory Nuclear Physics (2nd ed.). Weinheim: Wiley-VCH. pp. 9–10. ISBN 9783527617913.