Definition of Anion

An anion is a negative ion that is formed when a neutral atom belonging to a non-metal tends to accept one or more than one electron. In an electrochemical cell, these anions are carried towards the positive electrode of the cell which is termed an anode.

These non-metals have a high tendency to gain electrons and they typically exhibit such a phenomenon so that their noble gas configuration can be achieved. The elements which belong to the 7^th group of the periodic table need one electron to complete their outer shell. When they gain that electron, they become an anion.

Example of Anions:

Fluoride, chloride, iodide, etc. all are anions with a charge of -1. The decaying of teeth can be prevented by the usage of fluoride. Chloride maintains a balance between the salts of the body.