The correct order of atomic radii among the group 13 elements is-

1. B < Al < In < Ga < Tl
2. B < Al < Ga < In < Tl
3. B < Ga < Al < Tl < In
4. B < Ga < Al < In < Tl

An element that cannot form ${\mathrm{MF}}_6^{3-}$ ion is -
1. Ga
2. Al
3. B
4. In

The correct statement regarding inert pair effect is -

1. Sn²⁺ is an oxidizing agent while Pb⁴⁺ is a reducing agent

2. Sn²⁺ and Pb²⁺ both are oxidizing agents

3. Sn⁴⁺ is a reducing agent while Pb⁴⁺ is an oxidizing agent

4. Sn²⁺ is a reducing agent while Pb⁴⁺ is an oxidizing agent

AlF₃ is soluble in HF only in the presence of KF due to the formation of-

1.  ${\mathrm{K}}_3\left({\mathrm{AIF}}_3{\mathrm{H}}_3\right)$
2.  ${\mathrm{K}}_3\left({\mathrm{AIF}}_6\right)$
3.  ${\mathrm{AIH}}_3$
4.  $\mathrm{K}\left({\mathrm{AIF}}_3\mathrm{H}\right)$

It is because inability of ns² electrons of the valence shell to participate in bonding that

(1) Sn²⁺ is reducing while Pb⁴⁺ is oxidising agent

(2) Sn²⁺ is oxidising while Pb⁴⁺ is reducing agent

(3) Sn²⁺ and Pb²⁺ are both oxidising and reducing agent

(4) Sn⁴⁺ is reducing while Pb⁴⁺ is oxidising agent