Here's why:
* Barium ion (Ba²⁺): Barium is in group 2 of the periodic table, meaning it has two valence electrons. When it forms an ion, it loses these two electrons to achieve a stable octet, resulting in a +2 charge.
* Hydroxide ion (OH⁻): Hydroxide is a polyatomic ion consisting of one oxygen atom and one hydrogen atom. The oxygen atom shares electrons with the hydrogen atom, and the oxygen atom also has two lone pairs of electrons, giving the hydroxide ion a net negative charge.
