When light interacts with matter, it is abosrbed, reflected and transmitted. With repect to the UV-Vis range, electronic abosrptions occur, where if the incident photon mode matches the energy difference of electronic transitions in the atom, then the photon gets absorbed. What is happening during transmission? What property of the material allows for transmission of light? Please help me.
1 Answer
Transmission is just what happens to the light that is neither reflected nor absorbed.
The total energy of the light is a constant because energy is conserved. If the material has a refractive index different from one then some of the light is reflected, so some of the energy is lost to reflection. If the material has any form of excitation that can absorb light, e.g. an electronic transition, then some of the energy is lost to absorption and ultimately goes to heating up the material. The remaining energy is transmitted simply because it was neither reflected nor absorbed. There is no special property that causes transmission.
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$\begingroup$ Um don't you count as transmitted energy that is absorbed but re-emitted and not absorbed again? $\endgroup$ Commented Jan 5, 2017 at 16:16