* Ionic Compounds: Magnesium (Mg) is a metal and phosphorus (P) is a nonmetal. This suggests the formation of an ionic compound.

* Ionic Charges: Magnesium typically forms a +2 ion (Mg²⁺) and phosphorus typically forms a -3 ion (P³⁻).

* Balancing Charges: To balance the charges, we need two magnesium ions (+4 total charge) and three phosphorus ions (-9 total charge). This gives us the compound Mg₃P₂.

Therefore, Mg₂P₂ is not a valid chemical formula.