ion i·on (ī'ən, ī'ŏn')
An atom or a group of atoms that has acquired a net electric charge by gaining or losing one or more electrons.
|ion (ī'ən, ī'ŏn') Pronunciation Key
An atom or a group of atoms that has an electric charge. Positive ions, or cations, are formed by the loss of electrons; negative ions, or anions, are formed by the gain of electrons.
Institute of Nutrition