Anion

An anion is an ion that carries a negative electrical charge.

Anions are formed by the acquisition of electrons by a neutral atom or molecule. Thus, the anion has an excess of electrons compared to protons in the nucleus.

Anions, along with cations, play an important role in the formation of ionic compounds. In particular, salts consist of metal cations and anions of acidic residues.

The most common anions in nature are chloride ion (Cl-), hydroxide ion (OH-), nitrate ion (NO3-), carbonate ion (CO32-) and others.

Anions are widely used in industry, agriculture, and household chemicals. They play an important role in many chemical and biochemical processes.