Why does the reactivity of nitrogen differ from phosphorus?

(N/A) Nitrogen is chemically less reactive than phosphorus. This is primarily due to the high stability of the $N_2$ molecule. In $N_2$,the two nitrogen atoms are linked by a $p\pi-p\pi$ triple bond $(N \equiv N)$. This triple bond has a very high bond dissociation enthalpy,making it difficult to break under normal conditions. Due to its small atomic size,nitrogen can form stable $p\pi-p\pi$ multiple bonds,whereas phosphorus,being larger,prefers to form single bonds and exists as $P_4$ molecules with strained bonds. Consequently,phosphorus is much more reactive than nitrogen.