According to Bohr's theory of the atom, radiation takes place only when an electron goes from one orbit to an orbit closer the nucleus. If W represents the energy associated with an orbit, that is, the energy required to remove an electron from the orbit to infinity, the energy radiated when an electron goes from orbit (1) to orbit (2) will be W2 - W1 = h, where orbit (2) is closer the nucleus. Assuming that an absorption frequency corresponds to the energy associated with a ring of the Bohr atom, the difference between two absorption frequencies should give an emission frequency.
Proceedings of the Iowa Academy of Science
©1921 Iowa Academy of Science, Inc.
"The Alpha Lines in the "K" Series Tungsten Spectrum,"
Proceedings of the Iowa Academy of Science, 28(1), 117-118.
Available at: https://scholarworks.uni.edu/pias/vol28/iss1/24