Why does magnesium nitride form?

Answer 1

In general, metals tend to react with nonmetals because metals achieve a stable electron configuration by giving up electrons, and nonmetals achieve a stabel electron configuration by acquiring electrons, so when they get together, the metal can give electrons to the nonmetal and they both become more stable as a result. Magnesium is a metal, and nitrogen is a nonmetal. Magnesium gives electrons to nitrogen, thus forming magnesium nitride.

The atmosphere has 4 times as much nitrogen as oxygen and thus statistically some magnesium nitride will form when magnesium is burning in oxygen. Heat also increases side reactions and the formation of magnesium nitride while magnesium is burning in oxygen is a side reaction. Thus a combination of heat and statistics is the cause of magnesium nitride forming.