Anion: Definition

ANION definition: 1. an ion with a negative electrical charge 2. an ion with a negative electrical charge. Learn more. Learn the definition of cations and anions , their formation, and differences based on electric charge, reactions, etc. here at Embibe. An anion is an atom or molecule that has gained one or more electrons, giving it an overall negative electrical charge. The key difference lies in how they are formed and their resulting charge: an anion forms by gaining electrons (becoming negative), while a cation is formed by losing electrons (becoming positive). Anions are atoms or groups of atoms that have gained one or more electrons, resulting in a negative electrical charge.