How many electrons does the heteroatom (Nitrogen) exclusively contribute to the continuous, delocali — Aromatic Hydrocarbons Chemistry Question

💡 Solution & Explanation

In pyridine, the nitrogen atom is $sp^2$ hybridized. It uses two $sp^2$ orbitals for $\sigma$ bonds to adjacent carbon atoms, and the third $sp^2$ orbital holds its lone pair (which lies perfectly in the plane of the ring, orthogonal to the $\pi$ -system). Therefore, only the single unhybridized $p$ -orbital of nitrogen contributes exactly 1 electron to the aromatic $6\pi$ electron system.