# What is an atom that has gained or lost electrons called?

Jan 4, 2017

$\text{An ion............}$

#### Explanation:

Typically, metals lose electrons to form $\text{cations}$:

$N a \rightarrow N {a}^{+} + {e}^{-}$

This is an $\text{oxidation reaction}$.

And non-metals GAIN electrons to form $\text{anions}$ in a $\text{reduction reaction}$:

$\frac{1}{2} {O}_{2} + 2 {e}^{-} \rightarrow {O}^{2 -}$

Of course we combine the reactions to give the overall redox reaction:

$2 N a + \frac{1}{2} {O}_{2} \rightarrow N {a}_{2} O$