Often used with the same meaning as @S06012@, but in principle it is a microscopic quantity concerned with the individual collision process.
PAC, 1976, 46
, 71. (Manual of Symbols and Terminology for Physicochemical Quantities and Units - Appendix II. Definitions, Terminology and Symbols in Colloid and Surface Chemistry. Part II: Heterogeneous Catalysis
) on page 78 [Terms