The plots show examples of the Arrhenius equation for variations of the rate constant with temperature and activation energy for a typical chemical reaction; is a constant and is the universal gas constant. This explains how reactions are generally faster at higher temperatures. The lower plot depicts Maxwell speed distributions of molecules showing the fractions of molecules with sufficient energy to overcome the activation energy barrier, as a function of temperature. The shaded regions represent the values, which enable the reaction to proceed. These can be changed with the "activation energy" buttons.
Snapshot 1: In the top plot, alterations in temperature affect the rate constant at a low activation energy. In the bottom plot, the fraction of molecules in a generic reactants-to-products reaction that have enough energy to overcome the activation energy at user-defined temperatures appears as shaded regions.
Snapshots 2 and 3: The same as snapshot 1, but now showing how temperature affects and at medium and high activation energies. All snapshots are shown at 273 K.
The Maxwell speed distribution is used to model how a generic reaction is affected by temperatures of the reactant and product molecules. This distribution for gas-phase particles is modeled after kinetics of the aqueous decomposition of a benzenediazonium (BDA) derivative from aniline. In order to display adequate kinetics in the Demonstration, energy values were taken from  so that a real process could be modeled by the Maxwell speed distribution. This graph also includes a comparison to one-fourth of the molar mass of a regular BDA molecule.
Activation energy values and the decomposition reaction were derived from  for realistic kinetic parameters.
 M. L. Crossley, R. H. Kienle and C. H. Benbrook, "Chemical Constitution and Reactivity. I. Phenyldiazonium Chloride and Its Mono Substituted Derivatives," Journal of the American Chemical Society, 62(6), 1940 pp. 1400–1404. doi:10.1021/ja01863a019.