Which of the following molecules has a central atom that is sp^3 hybridized?

• A. C_2H_2
• B. CH_4
• C. CO_2
• D. BF_3

Answer: (B)

Verified step by step guidance

1. Identify the central atom in each molecule and determine its bonding environment.
2. Recall that sp^3 hybridization occurs when the central atom forms four sigma bonds or has four regions of electron density (including lone pairs).
3. For C_2H_2 (acetylene), the central atoms are carbons involved in a triple bond and a single bond, which corresponds to sp hybridization (two regions of electron density).
4. For CO_2, the central atom is carbon with two double bonds to oxygen, resulting in two regions of electron density, which corresponds to sp hybridization.
5. For BF_3, the central atom boron forms three single bonds with fluorine and has no lone pairs, resulting in three regions of electron density, corresponding to sp^2 hybridization.
6. For CH_4, the central carbon atom forms four single bonds with hydrogen atoms, resulting in four regions of electron density, which corresponds to sp^3 hybridization.