The development of the technology of electrothermal atomization in Atomic Absorption Spectrometry, described by the present author in monograph [1] about 50 years ago, led to a confrontation of two theoretical models used in the kinetics of heterogeneous chemical reactions: the activation model of Arrhenius [2] based on the effect of activation of reactants and the thermochemical model proposed by Langmuir [3] and later developed by L’vov, in which the existence of this effect is dismissed. Our investigations into atomization kinetics in the 1980s [4, 5], and the mechanism of solid decomposition, in the 1990s [6, 7], allowed eventually to develop and formulate a rigorous and consistent theory [8]. The latter is based on phenomenological thermodynamics (van’t Hoff’s isobar equation), statistical physics (Hertz ‒ Langmuir equation) and the mechanism of solid decomposition via congruent dissociative evaporation. The thermochemical model for the first time in the history of Thermal Analysis allowed a quantitative estimate and prediction of the lifetime of materials depending on the environment and the temperature of their storage. Presently, it allows the calculation of the rate of reaction [9‒12], taking into account the composition, stoichiometry and thermochemical characteristics (entropy and enthalpy changes) of the reaction, the excess pressure of the gaseous product in the reactor and the physical properties of the sample (its density and size). In the framework of this theory, it was possible to interpret many of the outstanding questions, including the physical nature of the A and E parameters in the Arrhenius equation, the mechanism of autocatalysis, the Topley–Smith effect and the kinetic compensation effect. In addition, potassium permanganate was selected as an ideal kinetic standard and the so-called “third-law method” was used to significantly improve the precision (up to 1-2 % RSD) in the determination of the E parameter. The spread of the thermochemical model can be hampered by the psychological barrier of applying the slightly different measurement and calculation procedure in comparison with ordinary versions. It is hoped that in the case of an impartial attitude of the ICTAC Kinetics Committee to this matter, this difficulty will be overcome by the efforts of the thermoanalytical community in the near future.