In ketones, the carbonyl group is bonded to two carbon atoms, while in aldehydes, it is bonded to at least one hydrogen atom. This difference in structure affects their reactivity and properties.

Acetone (CH₃COCH₃), the simplest ketone, and butanone (CH₃COCH₂CH₃) are common examples. Acetone is widely used as a solvent, while butanone is used in various industrial applications.

Ketones have higher boiling points than alkanes due to the polar nature of the carbonyl group, which creates dipole-dipole interactions between molecules.

Lower ketones, like acetone and butanone, are soluble in water because they can form hydrogen bonds with water molecules. Solubility decreases as the carbon chain length increases.