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In atomic physics, the Bohr model or Rutherford–Bohr model was the first successful model of the atom. Developed from 1911 to 1918 by Niels Bohr and building on Ernest Rutherford 's nuclear model , it supplanted the plum pudding model of J J Thomson only to be replaced by the quantum atomic model in the 1920s.
[169] [170] On 7 October 2012, in celebration of Niels Bohr's 127th birthday, a Google Doodle depicting the Bohr model of the hydrogen atom appeared on Google's home page. [171] An asteroid, 3948 Bohr, was named after him, [172] as was the Bohr lunar crater and bohrium, the chemical element with atomic number 107. [173]
Rutherford defined this position as being the element's atomic number. [75] [76] [77] In 1913, Henry Moseley measured the X-ray emissions of all the elements on the periodic table and found that the frequency of the X-ray emissions was a mathematical function of the element's atomic number and the charge of a hydrogen nucleus (see Moseley's law).
1935 Niels Bohr presents his analysis of the EPR paradox; 1936 Carl D. Anderson discovered the muon while he studied cosmic radiation; 1936 Alexandru Proca formulates the relativistic quantum field equations for a massive vector meson of spin-1 as a basis for nuclear forces; 1936 Eugene Wigner develops the theory of neutron absorption by atomic ...
It was formulated by Niels Bohr in the early 1920s. [12] This was an early application of quantum mechanics to the properties of electrons and explained chemical properties in physical terms. Each added electron is subject to the electric field created by the positive charge of the atomic nucleus and the negative charge of other electrons that ...
In some early papers, the model was called the "Bohr-Bury Atom". He introduced the word transition to describe the elements now known as transition metals or transition elements. [100] In the 1910s and 1920s, pioneering research into quantum mechanics led to new developments in atomic theory and small changes to the periodic table.
In 1913, Niels Bohr, a Danish physicist, introduced the concepts of quantum mechanics to atomic structure by proposing what is now known as the Bohr model of the atom, where electrons exist only in strictly defined circular orbits around the nucleus similar to rungs on a ladder. The Bohr Model is a planetary model in which the negatively ...
The Bohr–Sommerfeld model (also known as the Sommerfeld model or Bohr–Sommerfeld theory) was an extension of the Bohr model to allow elliptical orbits of electrons around an atomic nucleus. Bohr–Sommerfeld theory is named after Danish physicist Niels Bohr and German physicist Arnold Sommerfeld .