The systematic name for Mg(NO3)2 is Magnesium Nitrate.
To understand this, we break it down: Mg represents Magnesium, which is a metal from the alkaline earth metals group. The (NO3)2 indicates that there are two nitrate ions for every magnesium ion. A single nitrate ion (NO3-) comprises nitrogen and three oxygen atoms, and it carries a negative charge. Therefore, to balance the +2 charge of magnesium (Mg2+), we need two nitrate ions, resulting in the formula Mg(NO3)2. In naming, we typically place the name of the metal first followed by the name of the anion, in this case, nitrate. Thus, the complete systematic name becomes Magnesium Nitrate.