Why does the reactivity of nitrogen different from phosphorous?

Explanation

Nitrogen exists as a diatomic molecule with a triple bond between two N-atoms. The bond dissociation enthalpy of this triple bond (N=N) is very high (941.94 kJ `mol^(-1))` due to which nitrogen is inert and unreactive at room temperature. It contrast, phosphorus exists as a tetra-atomic molecule `(P_(4))`. As P-P bond is much weaker than N=N bond, therefore P— P bond can be broken easily and hence, phosphorus is much more reactive than nitrogen.