Explanation:
1s2 2s2 2p6 3s2 3p4
Oxidation number refers to the number of electrons that an atom gains or loses as it forms a chemical bond with another element.
From the electronic configuration above, it is expected that sulphur has oxidation number of 2. This is because the p orbital can hold a maximum of 6 electrons. However, in the electronic configuration it is just holding 4. To complete it, it needs to gain 2 more electrons.
