Which of the following polyatomic ions has a 3 ionic charge?

To determine which polyatomic ion has a 3 ionic charge, let’s look at the options provided:

• Hydroxide (OH^–): This ion has a -1 charge.
• Nitrate (NO₃^–): This ion has a -1 charge.
• Sulfate (SO₄^2-): This ion has a -2 charge.
• Phosphate (PO₄^3-): This ion has a -3 charge.
• Hydrogen Carbonate (HCO₃^–): This ion has a -1 charge.

Among these options, the phosphate ion (PO₄^3-) has a charge of -3. Therefore, it is the only polyatomic ion listed that exhibits a 3 ionic charge.