Q7 of 26 Page 1

State Bohr’s postulate of hydrogen atom which successfully explains the emission lines in the spectrum of hydrogen atom.

Use Rydberg formula to determine the wavelength of Hα line.


[Given: Rydberg constant R = 1.03 x 107 m–1]


According to Bohr’s postulate whenever an electron jumps from its non‐radiating orbit to another such orbit, the energy difference between the initial and final states is emitted in the form of energy. Mathematically



The Rydberg formula for the series is given by



The hydrogen line of the Balmer series is obtained when an electron jumps from third orbit to second orbit, i.e. ni =3 and nf = 2





The value of wavelength lies in the visible region.


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