The formula for barium phosphate is Ba3(PO4)2.
To break it down, barium (Ba) has a +2 charge, while the phosphate ion (PO4) carries a -3 charge. To create a neutral compound, we need three barium ions to balance the two phosphate ions. Hence, the formula reflects that ratio, resulting in Ba3(PO4)2, which signifies three barium ions and two phosphate groups in the compound.