This lecture covers the nature of the covalent bond, focusing on atomic orbitals, hybridization, formation of single and multiple bonds, electron delocalization, and resonance structures. It explains the Schrödinger equation, quantum numbers, representations of atomic orbitals, valence electrons, electronic configuration of carbon, and the VSEPR model. The concept of hybridization is explored through linear combinations of atomic orbitals, resulting in the formation of hybrid orbitals.