Chapter 4: Geometry

Using orbital theory as a foundation, Klein introduces hybridization (sp³, sp², and sp) as the key to predicting molecular shapes and explains how to determine hybridization states by counting bonded atoms and lone pairs. The chapter then applies Valence Shell Electron Pair Repulsion (VSEPR) theory to describe six basic molecular geometries: tetrahedral, trigonal pyramidal, bent, trigonal planar, and linear. Students learn how lone pairs affect molecular shape and how to quickly recognize geometries based on bonding patterns. The final section discusses exceptions to hybridization expectations, particularly when lone pairs participate in resonance and thus occupy unhybridized p orbitals. This foundational chapter equips learners with fast, reliable strategies for identifying hybridization states, predicting 3D structures, and understanding how geometry influences organic reactions.