Oxidation number nonintegral

Oxidation numbers are most often, but not always, integers. If there are nonintegral oxidation numbers, there must be multiple atoms so that the number of electrons is an integer. 

In this case, succinate metabolism to oxaloacetate produces 5 ATPs from the oxidation of the NADH and FADH2—2 from die FADH2 and 3 from the NADH. Two O s are consumed, 1 for each of the NADH and FADH2 molecules. The P/O is then 5/2 = 2.5. Thus the P/O can be a nonintegral number. 

In both P- and j9"-alumina, the conduction planes contain a nonintegral number of Na ions and there are considerably more sites available than Na ions to fill them. The structures are often described in terms of the supposedly ideal 1 11 stoichiometry with the formula NaAliiOi7. In such a case, of the three out of four oxide ions that are missing from the conduction planes, only one half of their vacant sites would contain a Na ion, as indicated schematically in Fig. 2.10. In practice, excess Na" ions are almost always present (e.g. ion A in Fig. 2.1(c)) but rarely in suflBcient quantities to fill all the available vacancies this then gives rise to the high carrier concentrations in these phases. 

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