What's wrong with Bohr's model of the atom?
2 Answers
The main problem with Bohr's model is that it works very well for atoms with only one electron, like H or He+, but not at all for multi-electron atoms. Bohr was able to predict the difference in energy between each energy level, allowing us to predict the energies of each line in the emission spectrum of hydrogen, and understand why electron energies are quantized.
Bohr's model breaks down when applied to multi-electron atoms. It does not account for sublevels (s,p,d,f), orbitals or elecrtron spin. Bohr's model allows classical behavior of an electron (orbiting the nucleus at discrete distances from the nucleus.
The application of Schrodinger's equation to atoms is able to explain the nature of electrons in atoms more accurately.
Defects of the Bohr's model are as follows -
1) According the the uncertainty principle, the exact position and momentum of an electron is indeterminate and hence the concept of definite paths (as given by Bohr's model) is out if question. Thus the concept of orbitals is thrown out.
2) It couldn't be extended to multi-electron systems. Systems that could work would be
Also, the Bohr's theory couldn't explain the fine structure of hydrogen spectrum and splitting of spectral lines due to an external electric field (Stark effect) or magnetic field (Zeeman effect).
It couldn't explain why some lines on the spectra where brighter than the others, i.e., why are some transitions in the atom more favourable than the others.
