Nitrogen is a chemically less reactive element because of the high stability of its molecular form ${{N}_{2}}$​. In nitrogen molecule​, the two nitrogen atoms form a triple bond among themselves. This triple bond has very high bond strength and much difficult to break down. It is due to nitrogen’s small size that it is able to form pπ-pπ bonds within itself. This property is not exhibited by the next atoms in the group 15 elements such as phosphorus. Hence, phosphorus is more reactive than nitrogen.