Niels Bohr won the 1922 Nobel Prize in Physics for his services in the investigation of the structure of atoms and of the radiation emanating from them.
Bohr proposed a model of the atom in 1913 in which electrons occupy specific energy levels. In this model, electrons can move between allowed levels by absorbing or emitting light at particular frequencies. The idea helped explain the line spectrum of hydrogen.
Bohr’s model was an important step toward modern quantum mechanics, although it was later replaced by more complete quantum theories. His institute in Copenhagen became a major center for theoretical physics and attracted many leading scientists.
The 1922 award citation did not use the simplified wording “quantum theory of atomic spectra,” but Bohr’s Nobel-recognized work is closely associated with that achievement. Max Planck, Schrödinger, and Heisenberg also made foundational quantum contributions, but they won Nobel Prizes in different years.