#anion  a negatively charged atom
  supertype:  #ion  an electrically charged particle; an atom that has lost one or more of its electrons
  subtype:  #hydroxide_ion__hydroxideion__hydroxyl_ion  the anion OH having one oxygen and one hydrogen atom
  subtype:  #superoxide_anion__superoxide  the univalent anion O2-; "much of the O2 supporting cellular respiration is reduced to the superoxide anion O2-"

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