Final answer:
Mg₃(PO₄)₂ is named magnesium phosphate, an ionic compound consisting of magnesium cations and phosphate anions.
Step-by-step explanation:
The correct name for the compound Mg₃(PO₄)₂ is magnesium phosphate. This compound is an ionic compound consisting of the magnesium cation (Mg²⁺) and the phosphate anion (PO₄³⁻). In naming ionic compounds, the metal cation name (magnesium) is written first, followed by the name of the polyatomic ion (phosphate), without changing the ending of the polyatomic ion's name.