The lead(IV) oxide used in car batteries is prepared by coating the electrode plate with PbO and then oxidizing it to lead dioxide (PbO₂). Despite its name, PbO₂ has a nonstoichiometric mole ratio of lead to oxygen of about 1/1.98. In fact, the holes in the PbO₂ crystal structure due to missing O atoms are responsible for the oxide’s conductivity.(a) What is the mole % of O missing from the PbO₂ structure?