What are functional groups in organic chemistry?

Functional groups are specific groupings of atoms within molecules that are responsible for the characteristic chemical reactions of those molecules. These groups determine the reactivity, polarity, phase of matter, and solubility of the compound. For example, the presence of an alcohol functional group (-OH) will impart different properties than a carbonyl group (C=O) would.

Recognizing functional groups is crucial in organic chemistry as they serve as the basis for classifying compounds and predicting their behavior in chemical reactions. Each functional group has distinct properties and reactivity patterns that offer a framework for understanding the chemistry of a wide range of organic molecules.

Other options focus on aspects that do not accurately represent the role of functional groups. For example, non-reactive elements and atoms that do not influence molecular properties do not relate to the essence of functional groups, which are specifically defined by their reactive characteristics. Additionally, the concept of isomer formation pertains to the structural diversity of molecules, rather than the defined role of functional groups within those molecules.