Question

Oxidation number to each element:
1. H^2
2. H^2O
3. Mg
NH^3
CI^2
I have hard time studying these concept.

Answer 1

Oxidation numbers are basically the charge on each element. If you use a periodic table, it's easier to understand and see what's going on. On the far right, you have noble gases. Take sulfur for example. It's two columns away from noble gases, and has 2 less electrons than the full set of 8 that noble gases have. As a result, sulfur has an oxidation number of -2. Do you get it? :)

Answer 2

So for H2, you have 1 electron, which gives you an oxidation number of +1.

Answer 3

Oops, +2, since you have 2 hydrogens.

Answer 4

On any homonuclear diatomic molecule, like \(H_2\) or \(Cl_2\), the oxidation state is 0.