• The oxidation numbers of all other atoms in their compounds can vary
• By following the oxidation number rules, the oxidation number of any atom in a compound or ion can be deduced
• The position of an element in the periodic table can act as a guide to the oxidation state

Oxidation Numbers & The Periodic Table

• Test your understanding on the following examples:

Answers:

Are oxidation numbers always whole numbers?

• The answer is yes and no
• When you try and work out the oxidation of sulfur in the tetrathionate ion?S₄O₆^2-?you get an interesting result!

The oxidation number of sulfur in S₄O₆^2-?is a fraction

• The fact that the oxidation number comes out to +2.5 does not mean it is possible to get half an oxidation number
• This is only a mathematical consequence of four sulfur atoms sharing +10 oxidation number
• Single atoms can only have an integer oxidation number, because you cannot have half an electron!