Phosphorus shows greater tendency for catenation than nitrogen. Why ?

Explanation

Due to smaller size, the Ione pairs of electrons on the two `N`-atoms repel the bond pair of `N-N` bond.In contrast, because of comparatively larger size of `P`, the Ione pairs of electrons on the two `P` atoms do not repel the bond pair of the `P-P` bond to the same extent.As a resultant, `N-N` single bond is weaker `(159 kJ mol^(-1))` than `P-P` single bond `(213 kJ mol^(-1))`.Consequently, nitrogen shows little tendency for catenation or phosphorus has greater tendency for catenation.