Question

____ tend to break apart in water to form a hydroxide ion.

answer options:
select one of four
bases
nonmetals
acids
metals

Explanation:

Bases are substances that, when dissolved in water, dissociate to produce hydroxide ions ($\text{OH}^-$). Acids produce hydrogen ions ($\text{H}^+$) in water. Nonmetals and metals do not typically break apart in water to form hydroxide ions. So the correct option is Bases.

Answer:

Bases