Answer:
D.) Mg(NO₃)₂
Step-by-step explanation:
Since magnesium (Mg) is a metal and nitrate (NO₃) is a polyatomic anion, they would combine to form an ionic compound. Magnesium would form the cation Mg²⁺ because it generally has 2 valence electrons. Nitrate always has a -1 charge.
In order for the overall compound to be neutral (have a charge of 0), there must be one Mg²⁺ and two NO₃⁻ ions in the compound (+2 + (-1) + (-1) = 0).
Therefore, the formula for the compound formed is Mg(NO₃)₂.