Question

The stability of + 1 oxidation state increases in the sequence:
(a) Tl < In < Ga < Al
(b) In < Tl < Ga < Al
(c) Ga < In < Al < Tl
(d) Al < Ga < In < Tl

Answer 1

option d is correct

Oxidation state of Boron family is + 3 but due to inert pair effect + 1 Oxidation State increase on going down the group