Grade 11 Chemistry (520 views)

Essentially, yes. A few elements have fixed (or at least very common) oxidation numbers/ionic charges (note: two different things, but equivalent in most ionic compounds) in ionic state, so you can use them to predict or find out the numbers or charges of other ion.

I recommend you watch this series of Khan Academy videos: www.khanacademy.org/science/chemistry/oxidation-reduction/redox-oxidation-reduction/v/introduction-to-oxidation-and-reduction

Here is a written guide as to determining oxidation numbers; remember, oxidation numbers and charges share values for most ions, so you can apply them to charges: uachemistry13.wordpress.com/2013/07/19/charge-v-oxidation-number/