# An ion is an atom that has had what added or removed?

Mar 17, 2017

An ion is an atom that has had one or more electrons added or removed.

#### Explanation:

Cations are atoms that have lost one or more electrons. Anions are atoms that have gained one or more electrons. The number of electrons lost or gained determines the numeric part of the charge.

Examples of Cations

$\text{Na"^(+)}$ sodium cation

$\text{Ca"^(2+)}$ calcium cation

$\text{Al"^(3+)}$ aluminum cation

Examples of Anions

$\text{N"^(3-)}$ nitride anion

$\text{O"^(2-)}$ oxide anion

$\text{F"^(-)}$ fluoride anion

Mar 17, 2017