What causes the emission of radiant energy that produces characteristics spectral lines?

1 Answer
Dec 27, 2015

From Bohr Model of the atom we see that when an electron jumps from an allowed orbit to another, radiant energy (photon) is emitted.


You can have an idea of the phenomenon observing the emission spectrum of hydrogen and the transitions responsible for it:

Red for example is emitted (and you see the red line in emission) when the electron "falls" from orbit at #n=3# to orbit with #n=2#.