Thermal Reactions Leading to the Emission Waves in Different Parts of the Electromagnetic Spectrum

Thermal reactions accompanied by emission of light (UV-Vis, IR, radio waves) are briefly reviewed. The Boltzmann law requires that molecules (atoms, ions, radicals, radical-ions) have distribution of energy levels according to the exponential law. Criteria for observation of emission of light quanta are presented. The well-known example is chemiluminescence, where a thermally “hot” molecular product returns to the ground state emitting light. Other types of similar reactions are presented. The observation of microwave emission is discussed.