The compound formed between magnesium ions (Mg²⁺) and phosphate ions (PO₃²⁻) is called magnesium phosphate.
To determine the formula for this compound, we need to balance the charges of the ions involved. The magnesium ion has a charge of +2, while the phosphate ion has a charge of -3. To balance these charges, we can use the least common multiple of the charges, which is 6.
This means we will need three magnesium ions (3 x +2 = +6) and two phosphate ions (2 x -3 = -6) to create a neutral compound. Therefore, the formula for magnesium phosphate is Mg₃(PO₃)₂.
In summary, the name of the compound is magnesium phosphate, and its formula is Mg₃(PO₃)₂.