See image — GOC and Organic Chemistry Basics Chemistry Question

💡 Solution & Explanation

**Understanding Benzene's π-System and External Unshared Orbitals** **Step 1: Identify the unshared electronic orbitals in benzene** Each carbon atom in benzene has one external unshared orbital perpendicular to the σ-framework plane. These are $p_z$ orbitals (one per carbon) that are not involved in C-C or C-H σ bonds. **Step 2: Recognize the spatial arrangement** In the planar benzene ring, the six $p_z$ orbitals are oriented parallel to each other, perpendicular to the molecular plane, and positioned adjacent to their neighbors around the ring. **Step 3: Assess orbital overlap capability** Since these $p_z$ orbitals are: - Properly aligned (all perpendicular to the plane) - Positioned in close proximity around the ring - Have favorable phase relationships They **can effectively overlap** to form π bonds. **Step 4: Explain the resulting π-system** These six overlapping $p_z$ orbitals form a **complete delocalized π-electron system** that extends over all six carbon atoms. This creates the characteristic aromatic π-cloud (electron density above and below the ring plane). **Step 5: Verify against other options** - (A) is incorrect—they do overlap to form bonds - (C) is incorrect—the overlap is not weak; it forms strong aromatic bonds - (D) is incomplete—they contribute to the entire aromatic ring stabilization, not just the "ring" structure **Answer: (B) can overlap to form a complete π bond** — The six external $p_z$ orbitals overlap effectively to create the delocalized aromatic π-system characteristic of benzene.