ANION, the constituent of an electrolyte (see ELECTROLYSIS) deposited at the anode (q.v.) by an electric current. When a molecule (q.v.) splits into electrically charged parts these are called ions (see IONIZATION). In the case of a liquid the negative ion is termed the anion and is non-metallic in character. It con sists of one or more atoms carrying a definite number of negative electric charges (see ELECTRON, THE), this number being called its valency (q.v.); e.g., the chlorine ion (Cr) and the group are both monovalent anions, while the group SO4 is a divalent anion. (See also CATION.)