How do you find an oxidation number of an element in a compound?
The oxidation state of an element in a compound is the charge left on the atom of interest when all the bonding pairs of electrons are formally broken, and the charged distributed to the most electronegative atom.
This definition is, I grant, a mouthful, but let's see how it is applied. We start with the water molecule,
Elements, of course, are considered to have
Elemental carbon is conceived to have been oxidized, i.e. it has lost 4 electrons to give
Now of course, these ideas of electron loss and electron gain are formalisms in that they have no actual reality, but often they allow us to balance redox reactions. I can give you a few ions with the oxidation numbers assigned:
Anyway, I hope this spray hasn't managed to confuse you totally. Remember, these are simple ideas, and they use very simple arithmetic.