The limitations of Bohr’s atomic model - QS Study
QS Study

Bohr’s theory of atomic model was quite successful in explaining the stability of atom and the line spectrum of hydrogen atom. However, several discrepancies were observed in this model. Some of the limitations of Bohr’s model are:

  • Bohr’s model of an atom could not explain the line spectra of atoms containing more than one electron called multi-electron atoms. According to Bohr’s theory, one and only one spectral line can originate from an electron between any two given energy levels. But if a powerful spectroscope, are used, certain single lines are found to split into a number of very closely related lines. The existence of such line could not be explained on the basis of Bohr’s theory.
  • Bohr’s theory failed to account for the effect of magnetic field on the spectra of atoms or ions. It was observed that when the atom emitting radiations is placed in a strong magnetic field each spectral line is further split into a number of lines. This phenomenon is known as Zeeman Effect.
  • Bohr’s theory could not explain the effect of electric field known as Stark effect on the spectra of atoms
  • Bohr’s theory does not provide any clue to explain the shapes of molecule arising out of the directional bonding between atoms.
  • The main objection of the Bohr’s theory came from the new principles namely dual nature of matter and uncertainly principle. They introduced the idea of wave character of electron in addition to its particles character and pointed out that the path of the motion of the electron cannot be well defined. Thus these over ruled the Bohr’s idea of well defined circular paths. Thus we find that Bohr’s model was only partially successful. It explained some experimental results but was unable to account for many other features of the atom. Therefore it was abandoned in the light of the modern ideas regarding the wave characteristics of matter.