oxalate molecule that reacts. The energy from the molecular
reaction will ultimately be used to release a photon or increase
the thermal energy of the molecules in the lightstick. Therefore
where E, is the energy released by the reaction, Ephoton is the
energy of the photon emitted, and Ethemwl is the increase in
thermal energy of the lightstick system. Even if every reacting
phenyl oxalate molecule resulted in an excited dye molecule
followed by emission of a photon, there would still be excess
energy. This is because the chemical excitation energy (Figure
2, CE) is always greater than or equal to the energy of the
photon the dye emits (Figure 2., CL). Also, not all of the energy
from this reaction is transferred to the dye; as one example, the
two CO2 molecules produced in step 2 of Scheme 1 could carry
away reaction energy through translations, rotations, and
vibrations. Thus, there will always be some thermal energy.
The photonic energy can be determined using the following
relation: