HPO₄²⁻ is the hydrogen phosphate ion, which consists of four oxygen atoms bonded to one phosphorus atom and carries two negative charges.
HPO₄²⁻ cheat sheet for homework
Phosphoric Acid (H₃PO₄): The parent compound from which HPO₄²⁻ is derived by losing one proton.
Phosphate Ion (PO₄³⁻): The fully deprotonated form of HPO₄²⁻, carrying three negative charges.
An ion composed of multiple atoms covalently bonded together that carries an overall charge.