Why does nitrogen show catenation properties less than phosphorus ?

Explanation

Nitrogen has lesser tendency for catenation than phophorus because N-N single bond is weaker than P-P single bond. The N-N single bond length is lesser than P-P single bond length because atomic size of N is less than that of P. Due to smaller interatomic distance in nitrogen the repulsive interactions between lone pairs on two nitrogen atoms is more. This weakens the N-N single bond. On the other hand, due to longer P-P single bond such repulsive interactions between lone pairs are almost absent in phosphorus. Thus makes P-P single bond stronger than N-N single bond.