Question

The +1 oxidation state is more stable than +3 oxidation state for Thallium. Explain why with reasons.

Answer 1

Dear Student,

This is due to Inert Pair effect. In p-block elements, as we move down the group the tendency of s-orbital to participitate in bond formation deacreases. Now, the s-orbital contain 2 electrons, so the oxidation state decreases by 2.
Hence, +1 oxidation state is more stable in Tl than +3 oxidation state.