Nitrogen

Concept: Delocalization of lone pair reduces pyramidal nature

Step 1: N has lone pair.

Step 2: Lone pair gets delocalized into Si orbitals.

Step 3: This reduces repulsion → structure becomes planar.
Conclusion:
Shape = Planar

Concept: Structure changes in solid state

Step 1: In gaseous state, N O is covalent.

Step 2: In solid state, it forms NO and NO ions.

Step 3: Hence behaves as ionic solid.
Conclusion:
Solid N O is ionic

Step 1: Understanding the Concept:
Hydrolysis of NCl produces NH and hypochlorous acid.

Step 2: Detailed Explanation:
Reaction: .
Nitrogen trichloride undergoes complete hydrolysis to ammonia and hypochlorous acid.

Step 3: Final Answer:
HOCl

Concept: Fractional oxidation states arise from mixed valency.

Step 1: Tend in Group 15. Down the group, inert pair effect increases → +3 oxidation state becomes more stable.

Step 2: Behaviour of Bismuth. Bi shows +3 and +5 oxidation states, tendency to form mixed-valence compounds → fractional oxidation states.

Step 3: Conclusion. Bi most commonly shows fractional oxidation states.