What is the chemical formula for copper(II) sulfate?

Copper(II) sulfate is a compound formed from copper ions and sulfate ions. The roman numeral II in copper(II) indicates that copper has a +2 oxidation state. The sulfate ion has a formula of SO₄ and carries a -2 charge. This means that to balance the charges, one copper ion (Cu²⁺) combines with one sulfate ion (SO₄²⁻), resulting in the formula CuSO₄.

The presence of a single copper ion and one sulfate ion means that the correct formula contains one of each, hence CuSO₄ accurately represents this balance of charges. The simplicity of this relationship is essential in determining the correct chemical formula for the compound. The other options do not correctly reflect this one-to-one relationship between copper and sulfate, either by including incorrect numbers of atoms or incorrect charges.