Why does nitrogen show catenation properties less than phosphorus?

Correct answer is (c) Iron 

(b) calcium and phosphorus

[Hint : Nitrogen is not having vacant d- orbitals in its octet, hence cannot expand its octet, while heavier members have vacant d-orbitals to expand their octet.]

[Hint : Because it have polymeric structure consisting chains of P4 tetrahedra, hence denser than white P while red P is not having angular strain as in white P, hence...

[Hint : (i) 4 (ii) Because due to presence of vacant d-orbitals in the octet of 'p', it can expand its octet to form PCl5, while N cannot expand its octet.]

Nitrogen owing to its small size has a tendency to form pπ−pπ multiple bonds with itself. Nitrogen thus forms a very stable diatomic molecule, N2. On moving down a group,...

The abscissa of the point of intersection of the less than type and of the more than type cumulative frequency curves of a grouped data gives its median.

(c) Assertion is correct, reason is incorrect 

 (b) White phosphorus exists as P4 tetrahedral molecule having P-P-P bond angle 60º. Hence the molecule is under strain and more reactive. On the other hand red phosphorus exists as...

(i) As N N triple bond (941.4 kJmol–1) is much stronger than p–p single bond (213 kJmol -1), therefore nitrogen is much less reactive than phosphorus (ii) This is because in...