An electrophile is best described as what?

• A. Nucleophile
• B. Electron pair acceptors
• C. Radical acceptors
• D. Electron pair donors

Answer: (B)

The key idea is that an electrophile is an electron pair acceptor. In Lewis acid–base terms, electrophiles are Lewis acids that seek electron density from electron-rich partners, i.e., they accept an electron pair. They’re typically electron-poor or positively charged, which is why they react with nucleophiles that donate electron pairs. A nucleophile, in contrast, donates electron pairs. Radical acceptors would involve unpaired electrons rather than lone pairs, and electron pair donors describe nucleophiles, not electrophiles. So the best description is that electrophiles are electron pair acceptors.