See image — GOC and Organic Chemistry Basics Chemistry Question

💡 Solution & Explanation

# Nucleophile Identification **Definition:** A nucleophile is an electron-rich species (has lone pairs) that attacks electron-deficient centers. **Analysis of each option:** **(1) $\dot{NO}_2$** — Nitrogen dioxide radical; has an unpaired electron, not a lone pair. Acts as an **electrophile**, not nucleophile. ✗ **(2) $:CCl_2$** — Dichlorocarbene; carbon is electron-deficient (only 6 electrons). Acts as an **electrophile**. ✗ **(3) $\dot{N}H_2$** — Nitrogen with lone pair and one unpaired electron. The lone pair on nitrogen makes it **electron-rich** and able to donate electron density to electrophilic centers. This is a **nucleophile**. ✓ **(4) $\dot{C}H_3$** — Methyl radical; has an unpaired electron but no lone pair. Acts as an **electrophile** in most contexts. ✗ **Answer: (3) $\dot{N}H_2$** The nitrogen atom possesses a lone pair of electrons that can be donated to form a new bond with an electrophilic center, satisfying the definition of a nucleophile.