Question

Discuss the pattern of variation in the oxidation state of the following:

Al to Tl

Answer 1

1. Group 13 elements show a +3 oxidation state primarily.
2. Boron shows only the +3 state.
3. From Al to Tl, the +3 state is common due to the loss of all three valence electrons (ns²np¹).
4. As we move down the group, stability of +1 oxidation state increases.
5. This is due to the inert pair effect, where s-electrons (ns²) are less inclined to participate in bonding.
6. Thallium (Tl) shows +1 state more commonly than +3.

Thus, oxidation states vary from +3 to +1 down the group (Al to Tl).