Definition of autoionization in English:


Pronunciation /ˌɔːtəʊˌʌɪənʌɪˈzeɪʃn/


(also autoionisation)
  • 1Chemistry
    The spontaneous ionization of a substance or molecule; a reaction between two identical neutral molecules, especially in a solution, to produce an anion and a cation.

  • 2Physics
    The spontaneous transition of an atom to an ionized state of lower energy with the emission of an electron (but no emission of radiation).


Early 20th century; earliest use found in Journal of the American Chemical Society. From auto- + ionization.