Atoms — Physics STD 12 Science — Question

Shortcomings of Bohr's Theory :
(i) Bohr's Theory explains the spectra of one-electron atoms only such as hydrogen, singly-ionised helium, doublyionised lithium, etc. It fails to explain the spectra of other atoms.
(ii) In this theory, nucleus assumed as stable, but it is possible only when mass of nucleus is infinite.
(iii) In this theory, orbits of electrons assumed circular while almost these are elliptical.
(iv) Bohr's theory does not explain about the intensities of spectral lines.
(v) On the basis of this theory quantization of angular momentum has no logical fact.
(vi) This theory does not explain the 'fine structure' of spectral lines.
(vii) The theory cannot fully explain the splitting of a spectral line into a number of components under the effect of a magnetic field. This effect is called Zeeman Effect, which is not explained by Bohr's theory In this way splitting of a spectral line under the effect of an electric field which is called Stark effect.