To name PbO2, one needs to know the charges on the ions. What is the charge on the cation in this compound?

In the compound PbO₂, lead (Pb) is the cation and oxygen (O) is the anion. To determine the charge on the lead cation, we first note that the oxide ion (O^2-) has a charge of -2.

Since there are two oxide ions in PbO₂, the total negative charge from the oxygens is:

Total Negative Charge = 2 (from O^2-) = 2 x -2 = -4

To achieve electrical neutrality in the compound, the total positive charge from the lead cation must exactly balance the total negative charge. Therefore, the charge on the lead cation must be +4. This is because:

Positive Charge from Pb = -Total Negative Charge

Positive Charge from Pb = +4 (to balance the -4 from the two O^2- ions)

Thus, the charge on the cation (lead, Pb) in PbO₂ is +4, and the correct name of the compound is lead(IV) oxide.