Question #0b6bf

+2

Explanation:

Barium, like the other alkaline earth metals, have two valence electrons. They have all have electron configurations that end $n {s}^{2}$.

These metals will lose two electrons when they form ions. This gives them a charge of +2 since they give away two electrons that each have a charge of -1.

Here are a few videos that may be helpful with this concept.

Hope this helps!