• Activation-based rate theory emerges as the unifying lens across gas and solution kinetics, linking activation energy, entropy, and steric factors to rate constants via the activated complex concept [1], [4], [8], [9].

• Radical and photochemical kinetics form a major strand, with OH radical rates tracked by absorption spectroscopy and electric discharge methods to reveal reaction pathways and radical lifetimes in multiple media [6], [12], [13].

• Surface/interface kinetics highlights adsorption and chemisorption at metal surfaces, surface action, and diffusion-controlled interfacial processes as primary rate determinants [3], [5], [16].

• Solution-phase kinetics stress solvent, electrolyte, and ionic effects on rates, including high-valence electrolytes and electrolyte-solvent interactions shaping rate constants in dilute aqueous media [7], [10], [11], [15].

• Gas-phase kinetics emphasize hydrogen–oxygen and hydrocarbon oxidation under low-pressure or discharge conditions, illustrating fundamental rate processes and radical-initiated reactions [14], [18], [20].