Reakci

Reakci is a term used in theoretical chemistry to denote an elementary reaction step within a broader reaction mechanism. It refers to a single transformation of reactants into products that occurs in one kinetic event and proceeds through a defined transition state.

In kinetics, an elementary step has a rate law that reflects its molecularity: for a bimolecular reakci A + B -> products, the rate is proportional to [A][B]; for a unimolecular reakci A* -> products, the rate is proportional to [A*]. In many models, a complex reaction mechanism is built from sequences of such elementary steps, collectively producing the observed overall rate.

Examples include enzyme-catalyzed steps, radical chain reactions, and simple gas-phase reactions such as A + B -> AB. However, many reactions in chemistry do not proceed via clearly identifiable elementary steps; their observed kinetics reflect a composite effect of multiple steps or fast equilibria. Thus the term "reakci" is used cautiously and is not universally standardized; some texts prefer "elementary reaction" while others use different terminology.

Etymology and usage: The form "reakci" is derived from the root for "reaction" found in several languages and appears in various non-English educational materials as a shorthand or transliteration. In English-language literature, "elementary step" or "elementary reaction" remains the common term.