It is shown that the accurate quantum-mechanical probability of the reaction of H with H2, with either zero or one unit of total angular momentum, increases with energy by increments of resolvable 'quanta' of reactive flux. These are analysed in terms of quantized transition states. Bend and stretch quantum numbers are assigned for total angular momentum J equal to zero and for both parities for J = 1 based on an analysis of the density of reactive states. A more detailed description of the reactive scattering process has been obtained by examining the state-selected densities of reactive states, and the initial H + H2 channels that contribute to the reactive flux passing through specific transition states have been determined.
