Detailed Breakdown: From Models to Materials
Orbital Hybridization: The VSEPR model is extended by hybridization theory, where atomic orbitals mix to form new, equivalent hybrid orbitals ($sp, sp^2, sp^3$). This explains how carbon can form four identical bonds in a tetrahedral arrangement in methane.
Sigma ($\sigma$) and Pi ($\pi$) Bonding: Single bonds consist of one $\sigma$ bond (formed by head-on overlap). Double bonds consist of one $\sigma$ and one $\pi$ bond (formed by sideways overlap of p-orbitals). $\pi$ bonds are Electron-rich and cannot rotate, which is central to organic reactivity and isomerism.
Complexes: Transition metals form colorful complexes by coordinating with ligands. The splitting of d-orbitals explains their color and magnetic properties.