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Electron affinity

THe electron affinity is the nergy required to detach an electron from the singly charged negative ion (energy for the process X -> X + e). The equivalent more common definition is the energy released (Einitial + Efinal) when an additional electron is attached to a neutral atom or molecule. [IUPAC Compendium of Chemical Terminology (Gold Book), 2nd Edition (1997)]

image showing Electron affinity: period 5sp periodicity for 5s and 5p chemical elements


kJ mol-1



Literature sources

  1. J.E. Huheey, E.A. Keiter, and R.L. Keiter in Inorganic Chemistry : Principles of Structure and Reactivity, 4th edition, HarperCollins, New York, USA, 1993.
  2. A.M. James and M.P. Lord in Macmillan's Chemical and Physical Data, Macmillan, London, UK, 1992.
  3. J.C. Wheeler in J. Chem. Ed., 1997, 74, 123-127.