updated November 11, 2009; text only, no
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Rules for assigning oxidation numbers:
- #1 - ON = 0 for all elements.
- #2 - ON = charge for monatomic ions
also, these corollaries:
ON = +1 for Grp. I elements in compounds
ON = +2 for Grp. II elements in compounds
ON = +3 for Aluminum in compounds (Grp. III)
- #3 - in other compounds: (apply these in order)
ON = -1 for fluorine
ON = +1 for hydrogen
ON = -2 for oxygen
- #4 - sum rule: (use for last element)
sum of ON's = 0: in any neutral molecule
sum of ON's = charge: in any ion
From Brown & LeMay (11th Edit.), p. 137.
© 2009 Dr. R. S. Strange