Emission Spectrum and Atomic Spectrum

[sonalivij]

I always thought light worked in such a way that all the wavelengths absorbed were not seen, and the wavelengths reflected were seen. How is it that the absorption spectrum and the emission spectrum have the same absorption and emission lines? Am I understanding this wrong...?

[Sarah Jeong 4F]

Hi sonalivij,
If you're asking about the photoelectric effect, then it is true that we only see light(from e- emission) that is reflected. But the light that is absorbed is also seen because we are pointing actual photons(lights) into the metal. That is why we see the light that is being absorbed and the one that is reflected.

[Karina Koo 2H]

not sure if this is completely correct, but i think that this is because light being emitted and light being reflected are two different things. The light that is reflected is simply never absorbed and just bounces back because it doesn't match the energy required to bring the electron to a higher level of excitation. The light that is being emitted, on the other hand, was absorbed already and is only later emitted when the electron loses its excited state and moves back down to its original orbital. That way, the wavelengths that can be absorbed are the same that are emitted, because the emission is just the effect of a photon of a certain energy already being absorbed and the same energy is just getting emitted afterwards.