Final answer:
The carbon three positions away from the carbonyl carbon is conceptually known as the gamma carbon, but its specific name in a molecule would depend on the structure and substituents.
Step-by-step explanation:
The carbon atom that is three positions away from the carbonyl carbon in a molecule is commonly referred to in organic chemistry nomenclature. In the context of a ketone, where the carbonyl carbon is bonded to two other carbon groups, identifying carbons relative to the carbonyl group becomes critical.
For example, if we consider the simplest ketone, acetone, we see that the carbon adjacent to the carbonyl carbon are termed alpha carbons. The next carbon is the beta carbon, and thus, the one following would be the gamma carbon. However, in practice, organic chemists would seldom refer to the gamma carbon, and the naming would depend on the longest carbon chain and the functional groups present. Therefore, while the carbon three positions away from the carbonyl group can be conceptually referred to as the gamma carbon, its specific name in a given molecule would depend on the overall structure and substituents present.