Nitrogen is known to differ form other members of the family because of the following facts,

(1) Its small size (2) Its high electronegativity (3) Its high ionization energy (4) non-availability of d-orbital in the valence shell. (5) Its capacity to form pπ-pπ multiple bonds.

(i) Nitrogen is a gas while other members are solids.

(ii) Nitrogen is diatomic while other elements like phosphorus and arsenic form tetra-atomic molecules ( P₄, As₄ ) .

(iii) Nitrogen form five oxides ( N₂O, NO, N₂O₃, N₂O₄ and N₂O₅ ) while other members of the family form two oxides (tri and pentaoxides).

(iv) Hydrides of nitrogen show H-bonding while those of other elements do not.

(v) Nitrogen does not show pentacovalency because of absence of d-orbitals while all other elements show pentacovalency.

(vi) Nitrogen dos not form complexes because of absence of d-orbitals while other elements show complex formation e.g., [ PCI₆ ]^-, [AsCI₆]^- etc.

(vii) The hydride of nitrogen ( NH₃ ) is highly basic in nature while the hydrides of other elements are slightly basic.

(viii) Except for NF₃, , other halides of nitrogen e.g., NCI₃, NBr₃ and NI₃ are unstable.