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5.ATOMIC STRUCTURE eLearn.Punjab

The spectral lines of Lyman series are produced when the electron jumps from n2= 2, 3,4,5, to, n,
= 1 (Lyman did not know this reason). Similarly, spectral lines of Balmer series discovered in 1887

originated when an electron jumps from n2 = 3, 4, 5, 6,................. to n1= 2orbit.
In the same way, Paschen, Brackett and Pfund series of lines are produced as a result of

electronic transitions from higher orbits to 3rd, 4th and 5th orbits, respectively Fig (5.17).

Fig (5.17) Electronic transitions in hydrogen atom and series of spectral lines, justified by Bohr's model atom

Calculations of Wave Numbers of Photons of Various Spectral Series by Bohr’s Theory

The wavelength ( l ) or wave number ( v ) of a spectral line depends on the quantity of energy
emitted by the electron. Suppose, an electron jumps from n2 to n, and emits a photon of light.
According to Bohr’s equation of energy

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