Determine the oxidation number of each atom in the following compounds: sodium chloride and iron oxide.

Oxidation number of each atom Sodium chloride NaCl

Sodium is in group 1 in the periodic table so it always going to have + 1 charge for its oxidation number.

chlorine in group 7 called halogen gas will almost always have - 1 charge for its oxidation number except for very few exceptions.

2. iron oxide Fe (2) O (3)

Oxygen usually have the oxidation number of - 2 unless bonded to F or H (2) O (2). We have 3 Oxygen atoms so 3 * (-2) = - 6

Now we have 2 iron atoms and we need total + 6 charge of the iron so that 2*x = + 6 and that is + 3.

So the oxidation number of Fe is + 3.