Identify the cation and anion in the compound Mg(NO3)2. Here, Mg is the cation (magnesium ion) and NO3 is the anion (nitrate ion).
Determine the charge of the cation and anion. Magnesium typically forms a +2 charge (Mg^{2+}), and nitrate is a polyatomic ion with a -1 charge (NO_3^{-}).
Since there are two nitrate ions to balance the +2 charge of magnesium, the formula Mg(NO3)2 is electrically neutral.
Name the cation first using its element name: 'Magnesium'. Since magnesium has only one common oxidation state (+2), no Roman numeral is needed.
Name the anion by using the name of the polyatomic ion: 'nitrate'. Combine the names to get the systematic name: 'Magnesium nitrate'.