The number of reactant @M03986@ that are involved in the '@M03910@' constituting an @E02035@. (For reactions in solution this number is always taken to exclude molecular entities that form part of the @M03814@ and which are involved solely by virtue of their @S05747@ of solutes.) A reaction with a molecularity of one is called 'unimolecular', one with a molecularity of two 'bimolecular' and of three 'termolecular'.
See also:
chemical reaction
order of reaction
PAC, 1993, 65, 2291. (Nomenclature of kinetic methods of analysis (IUPAC Recommendations 1993)) on page 2296 [Terms] [Paper]
PAC, 1994, 66, 1077. (Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994)) on page 1143 [Terms] [Paper]
PAC, 1996, 68, 149. (A glossary of terms used in chemical kinetics, including reaction dynamics (IUPAC Recommendations 1996)) on page 175 [Terms] [Paper]