Barium sulfate (BaSO₄) is a neutral compound. It doesn't form negative ions.

Here's why:

* Barium (Ba) is a metal, and metals tend to form positive ions (cations).

* Sulfate (SO₄²⁻) is a polyatomic ion with a negative charge.

In barium sulfate, the positive charge of the barium ion (Ba²⁺) balances the negative charge of the sulfate ion (SO₄²⁻), resulting in a neutral compound.