p Block Elements Part 3

(A) In the case of nitrogen, all oxidation states from +1 to +4 tend to disproportionate in acid solution. For example.$3\,\mathrm{HNO}_2 \longrightarrow \mathrm{HNO}_3+\mathrm{H}_2\mathrm{O}+2\,\mathrm{NO}$(B) Nitrogen form $p_{\pi}-p_{\pi}$ bonds with itself and other elements with small size and high electronegativity, $d_{\pi}-p_{\pi}$ is not possible with itself as it has no d-orbital.(C) The single $N-N$ bond is weaker than the single $P-P$ bond because of high intereelecronic repulsion of the non-bonding electrons (lone pair), owing to the small bond length.(D) Nitrogen has lowest density in its group.(E) The maximum covalency of nitrogen is four.