chemistry
posted by Noel on .
What is the oxidation number of PO4 in the compound Ca3(PO4)2? how do you get it?

You know the PO4 has a net charge of 3
by the rules, O is 2, so 4 of those makes O carry a total of 3
Finally, the rules state then the sum of the oxidation numbers equals the charge...
X8=3
solve for X 
6 years later

3