# When does an element become a positive ion?

Dec 31, 2016

When it gives up (loses) a valence electron.

#### Explanation:

For example, sodium metal reacts with water, giving up an electron to the hydrogen ion, producing sodium ions (positive) and elemental hydrogen.

$N a + {H}_{2} O \to N {a}^{+} + \left(O {H}^{-}\right) + {H}_{2}$