Stability of monovalent and trivalent cations of Ga, In, Tl lie in the following sequence

Options

A. `Ga^(3+)lt In^(3+)gt Tl^(3+)`
B. `Ga^(3+)gt In^(3+)gt Tl^(3+)`
C. `Tl^(o+)gt In^(o+)gt Ga^(o+)`
D. `Ga^(o+)gt In^(o+)gt Tl^(o+)`

Answer

B, C

Explanation

`{:(Ga^(+3)gt In^(+3)gt Tl^(+3)),(Tl^(+)gt In^(+)gt Ga^(+)):}}` due to inert pair effect.