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)]
- 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.
- A.M. James and M.P. Lord in Macmillan's Chemical and Physical Data, Macmillan, London, UK, 1992.
- J.C. Wheeler in J. Chem. Ed., 1997, 74, 123-127.