IUPAC definition : A defined linked collection of atoms or a single atom within a molecular entity. This
use of the term in physical organic and general chemistry is less restrictive than
the definition adopted for the purpose of nomenclature of organic compounds.;
A defined linked collection of atoms or a single atom within a molecular entity. This
use of the term in physical organic and general chemistry is less restrictive than
the definition adopted for the purpose of nomenclature of organic compounds.