See image — GOC and Organic Chemistry Basics Chemistry Question

💡 Solution & Explanation

# Resonating Structures of Biphenyl **Understanding Resonance:** Resonance structures show different distributions of electrons (pi bonds and lone pairs) while keeping atom positions fixed. They represent a single hybrid structure, not separate molecules. **Analysis of Biphenyl ($C_6H_5-C_6H_5$):** The two benzene rings are connected by a single $C-C$ bond. Each ring independently maintains its aromatic sextet through resonance within that ring. **Evaluating Options:** **(A)** Shows formal charges (⊕ and ⊖) — This violates the basic principle that resonance structures of a neutral molecule cannot have separated charges without significant stabilization. Biphenyl has no charge separation. **(B)** Shows both rings with alternating double/single bonds — This correctly represents legitimate resonance forms where: - Electron density shifts within each ring independently - No formal charges appear - The $C-C$ linkage remains a single bond - Both aromatic systems are preserved **(C)** Shows opposite formal charges on different rings — Similar to (A), this creates unrealistic charge separation in a neutral molecule. **(D)** All of these — Incorrect since (A) and (C) don't represent valid resonance structures. **Answer: (B)** is correct because it shows realistic resonance structures with electron redistribution within the aromatic rings while maintaining neutrality and the characteristic biphenyl structure.