1. The Gro hus-Draper law states that radia on must be absorbed by a chemical substance for a photochemical reac on to occur. To use a specific LED in the game, a reac on mixture must contain at least one chemical compound that absorbs photons of interest. Compa bility of chemicals modelled in the game with the LEDs was assigned mainly based on the published data. Table collects photochemical reac ons, in which a specific chemical was studied, the wavelength used in the experiment and the corresponding photon energy (kJ mol -1 ). In some cases, the assignment was made considering UV-vs absorp on spectrum of a compound, its cross-sec on, or bond dissocia on energy. In some cases, however, chemicals were arbitrary included in the list as absorbers of VIS, UVA or UVC photons to increase the scope of chemicals compa ble with the specific LED. 2. Only one-photon excita on is permi ed, i.e., players can only add one mole of photons and as such lower ΔH 0 and ΔG of a reac on by 199, 341 or 664 kJ mol -1 .