Final answer:
The carbon atom bonded to oxygen in propanone is sp² hybridized, which includes three sigma bonds and one pi bond, resulting in a bond angle of around 120 degrees.
Step-by-step explanation:
The hybridization of the carbon atom bonded to oxygen in propanone (commonly known as acetone) is sp² hybridization. In propanone, the carbon of the carbonyl group (C=O) has two other sigma bonds with other carbon atoms, making a total of three sigma bonds (including the one with oxygen), and one pi bond with oxygen, characteristic of sp² hybridization. The bond angle associated with sp² hybridization is approximately 120 degrees.