Negative and Positive Oxidation state:
- The elements of Group 16 exhibit a number of oxidation states (Above Table).
- The stability of -2 oxidation state decreases down the group.
- Polonium hardly shows –2 oxidation state.
- Since electronegativity of oxygen is very high, it shows only negative oxidation state as –2 except in the case of OF2 where its oxidation state is + 2.
- Other elements of the group exhibit + 2, + 4, + 6 oxidation states but + 4 and + 6 are more common. Sulphur, selenium and tellurium usually show + 4 oxidation state in their compounds with oxygen and + 6 with fluorine.
- The stability of + 6 oxidation state decreases down the group and stability of + 4 oxidation state increase (inert pair effect).
- Bonding in +4 and +6 oxidation states are primarily covalent.