Chemistry
Chemistry
Problem
The inability of the Bohr model to account for the fine structure of hydrogen spectral lines is mainly due to its neglect of a) neglect of the wave nature (de-Broglie behaviour) of the electron b) finite mass (recoil) of the nucleus not being taken into account c) relativistic mass variation and electron spin d) restriction to perfectly circular orbits (no elliptical paths)Intuitive explanation
The Bohr model treats the electron as a classical particle moving in fixed orbits, but it ignores a crucial quantum property: electron spin and its interaction with the orbital motion. When you account for spin-orbit coupling—how the electron's intrinsic angular momentum couples with its orbital angular momentum—you get small energy shifts that split what Bohr predicted as single lines into closely spaced doublets. This is the fine structure, and it's invisible to Bohr because his model has no room for spin at all.
Intuitive explanation
The Bohr model treats the electron as a classical particle moving in fixed orbits, but it ignores a crucial quantum property: electron spin and its interaction with the orbital motion. When you account for spin-orbit coupling—how the electron's intrinsic angular momentum couples with its orbital angular momentum—you get small energy shifts that split what Bohr predicted as single lines into closely spaced doublets. This is the fine structure, and it's invisible to Bohr because his model has no room for spin at all.