The surface of this moon is hidden beneath a thick orange photochemical smog.
Initiation, propagation, termination... The reaction of hydrogen and chlorine is a typical photochemical chain reaction involving radicals.
Edmond Becquerel was associated with his father in much of his work, but he himself paid special attention to the study of light, investigating the photochemical effects and spectroscopic characters of solar radiation and the electric light, and the phenomena of phosphorescence, particularly as displayed by the sulphides and by compounds of uranium.
The word actinometer is now usually applied to instruments for measuring the actinic or chemical effect of luminous rays; their action generally depends upon photochemical changes.