The quantization of the atom in three acts (Q2746693)

The author presents the three different approaches that led to the explanation of the Balmer series of hydrogen. The first application of the quantum concept in order to resolve the problem of atomic spectra was made by Niels Bohr. Convinced that Planck's quantum was crucial to an understanding of the atom, Bohr published his model of a quantized atom in 1913. A coherent theory of the quantized atom was provided by Heisenberg in 1925. Heisenberg's mathematical formalism was embedded in the language of matrices by Born and Jordan, and with this knowledge, Pauli successfully applied the new quantum mechanics to the hydrogen atom. The third approach to the quantization of the atom was provided by Schrödinger in 1926. This version of quantum theory was called wave mechanics in order to distinguish it from Heisenberg's matrix-based formalism. The paper ends with an outlook on the relativistic quantization of the atom and especially on the contributions made by Dirac, Lamb, and Bethe.