[Answer] Which rule for assigning oxidation numbers is correct?

Answer: Oxygen is usually -2.

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Which rule for assigning oxidation numbers is correct? This approach yields correct oxidation states in oxides and hydroxides of any single element and in acids such as H 2 SO 4 or H 2 Cr 2 O 7. Its coverage can be extended either by a list of exceptions or by assigning priority to the postulates. The latter works for H 2 O 2 where the priority of rule 1 leaves both oxygens with oxidation state −1. General rule . From Wikipedia:Naming ... is assigned its oxidation number . Except in rare cases (none at present) we do not assign the oxidation number in the anion: hence potassium permanganate ... ignoring any prefixes and numbers . Correct article names and first words in sentences are: 1 1 1-Trichloroethane not 1 1 1-trichloroethane; Stock nomenclature for inorganic compounds is based on the indication of the oxidation number (as a roman numeral in parentheses) of each of the major elements in the compound e.g. iron(III) chloride. It is widely if sometimes incorrectly used on Wikipedia for the titles of articles about inorganic compounds. Fractional oxidation numbers . What about s...

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