How do I assign oxidation numbers to a chemical formula. Is there an easy way?

I need help. I am in introductory chemistry and need guidance when it comes to assigning oxidation numbers to a chemical formula. Is there an example that someone can show me and explain to me the process. Any and all help is greatly appreciated. Thank YouHow do I assign oxidation numbers to a chemical formula. Is there an easy way?
Well, keep in mind that all the pure elements such as, Mg, O2, H2, Ca etc.. have 0 oxidation number.





Here's a helpful site that can show and explain how to calculate oxidation numbers.


http://www.chemguide.co.uk/inorganic/red鈥?/a>How do I assign oxidation numbers to a chemical formula. Is there an easy way?
Hii i'm in chemistry too and i just started to get this stuff so maybe this will help :)








You assign the oxidation numbers solely through the use of the periodic table. You should know that any element alone, or in its elemental state will always have the oxidation number of zero. Because any element not in a bond with another element will have no charge, because the net zero always has to be zero except in special elemental bonds.


So for example





Na(s) + Cl(g) ------%26gt; NaCl


The ox # of both the Na and the Cl on the left side of the equation before they are bonded are 0 because they are not bonded yet and are in there elemental states. But on the right side of the equation they are no longer unbonded. They now share an ionic bond, and this is where assigning oxidation numbers and the periodic table come in.





Since Na is in the 1st column of the periodic table we know that it should have the charge of +1, and since Cl is in the seventh column (not counting transition metals) it should have the charge of -1. So you would only need one Na to balance out one Cl, because +1-1=0 and the goal is to have the net zero of zero. So if Cl had the charge of -2 then you would need 2 Na's to balance out the Cl, making the final product look like 2Na+Cl -----%26gt; 2Na(subscript 2)Cl.





The families starting in the following have the following charges throughout there columns:





H- +1


Be- +2


B- +3


C- +4


N- -3


O- -2


F- -1


Ne- 0 charge

















[**note the Cl should be Cl with a subscript of 2 because it is one of the seven diatomic atoms found in nature]