What is the oxidation state of Pb in Pb3O4?

The nominal oxidation state of Pb in this compound is + 8/3, because oxygen is taken to have a minus two oxidation state; the four oxygen atoms therefore have a total charge of -8, and the three lead atoms must have a nominal oxidation state of + 8/3 to balance them. This variation from the normal rule that oxidation states must have whole number values arises because in Pb3O4, two-thirds of the lead atoms have an oxidation state of +2 and the remaining one-third of the lead atoms have an oxidation state of +4, thereby providing a total of +8 electric charges from three lead ions.