Final answer:
The formula of magnesium nitride is c) Mg₃N₂. Magnesium forms a 2+ charged ion, and nitrogen forms a 3- charged ion, resulting in the 3:2 compound Mg₃N₂, a neutral ionic compound. Option c is correct.
Step-by-step explanation:
The formula of magnesium nitride is c) Mg₃N₂. When magnesium and nitrogen react to form an ionic compound, magnesium forms a magnesium ion with a 2+ charge (Mg2+) by losing two electrons. This occurs because magnesium is in group 2 of the periodic table and tends to lose electrons to achieve the electron configuration of the nearest noble gas, which is neon in this case.
Nitrogen, on the other hand, tends to gain three electrons to achieve the electron configuration of neon, forming an anion with a 3- charge called a nitride ion (N3-). The 2+ charge of the magnesium ion balances with the 3- charge of the nitride ion in a ratio of 3:2 to form the neutral compound Mg₃N₂, which is magnesium nitride.