An sp3 hybridized carbon has a ________ molecular geometry and forms a bond angle of _____.

• A. Linear; 180 degrees
• B. Tetrahedral; 109.5 degrees
• C. Trigonal planar; 120 degrees
• D. Trigonal planar; 109.5 degrees

Answer: (B)

sp3 hybridization around carbon creates four equivalent orbitals arranged toward the corners of a tetrahedron. This setup distributes the four substituents as far apart as possible, giving a tetrahedral molecular geometry. The ideal angle between any two bonds in a tetrahedron is about 109.5 degrees, so an sp3-hybridized carbon forms bonds with approximately this angle. If you had only three substituents, you’d get trigonal planar geometry with ~120-degree angles; with two substituents, linear geometry with ~180 degrees. Real molecules may deviate slightly, but the core idea remains: four substituents, tetrahedral shape, ~109.5-degree bond angles.