Why does nitrogen show catenation properties less than phosphorus

Why does nitrogen show catenation properties less than phosphorus?

 Answer 

Catenation is much more common in phosphorous compounds than in nitrogen compounds. This is because of the relative weakness of the N−N single bond as compared to the P−P single bond. Since nitrogen atom is smaller, there is greater repulsion of electron density of two nitrogen atoms, thereby weakening the N−N single bond.