The hybridization of the carbonyl carbon in aldehydes and ketones is described as sp² hybridization. In sp² hybridization, one s orbital and two p orbitals combine to form three sp² hybrid orbitals. These orbitals arrange themselves in a trigonal planar geometry around the carbon, providing a stable structure for the carbonyl group. The carbon-oxygen double bond in the carbonyl group consists of one σ bond formed by the overlap of sp² hybrid orbitals and one π bond formed by the side-to-side overlap of unhybridized p orbitals. This results in a planar and relatively rigid carbonyl functional group.