How many sigma bonds does the following molecule contain?

• A. 12
• B. 8
• C. 9
• D. 10

Answer: (C)

Verified step by step guidance

1. Identify the structure of the molecule in the image. The molecule is propanone, commonly known as acetone, with the chemical formula C3H6O.
2. Understand that a sigma bond (σ bond) is the strongest type of covalent chemical bond formed by the head-on overlapping of atomic orbitals.
3. Count the number of single bonds in the molecule. Each single bond is a sigma bond. In the structure, each carbon atom forms single bonds with hydrogen atoms and other carbon atoms.
4. Observe that the central carbon atom is double-bonded to the oxygen atom. In a double bond, one bond is a sigma bond and the other is a pi bond. Therefore, the C=O bond contains one sigma bond.
5. Add up all the sigma bonds: 6 C-H bonds, 2 C-C bonds, and 1 C=O bond, resulting in a total of 9 sigma bonds in the molecule.