Question

Explain:
1) Stability of +3 state in nitrogen family increases from top to bottom.
2)Amongst $LiF$ and $LiI$ which has more covalent character.

Answer 1

(1) As we move down to the Nitrogen family, s orbital perpetrates and come loser to the nucleus so experience greater nuclear alteration and does not participate in bonding. That's why stability of low oxidation state Increases down the group

Note: The above effect is called Inert pair effect

(2) $LiI$ has more covalent character than $LiF$

According to fajan's rule " with an increase in the size of Anion the covalent character in a molecule Increase "

So, size : $I>F$

So, $LiI>LiF$ : covalent character