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History of atomic theory. The current theoretical model of the atom involves a dense nucleus surrounded by a probabilistic "cloud" of electrons. Atomic theory is the scientific theory that matter is composed of particles called atoms. The definition of the word "atom" has changed over the years in response to scientific discoveries.
1924 Satyendra Bose and Albert Einstein introduce Bose–Einstein statistics. 1925 George Uhlenbeck and Samuel Goudsmit postulate electron spin. 1925 Pierre Auger discovers the Auger process (2 years after Lise Meitner) 1925 Werner Heisenberg, Max Born, and Pascual Jordan formulate quantum matrix mechanics.
1888 – Johannes Rydberg modifies the Balmer formula to include all spectral series of lines for the hydrogen atom, producing the Rydberg formula that is employed later by Niels Bohr and others to verify Bohr's first quantum model of the atom. 1895 – Wilhelm Conrad Röntgen discovers X-rays in experiments with electron beams in plasma.
1947. Kaon (or K meson), the first strange particle, discovered by George Dixon Rochester and Clifford Charles Butler [ 17 ] 1950. Λ0 (or lambda baryon) discovered during a study of cosmic-ray interactions [ 18 ] 1955. Antiproton discovered by Owen Chamberlain, Emilio Segrè, Clyde Wiegand, and Thomas Ypsilantis [ 19 ] 1956.
Electrons and a compact nucleus of protons and neutrons. Atoms are the basic particles of the chemical elements. An atom consists of a nucleus of protons and generally neutrons, surrounded by an electromagnetically bound swarm of electrons. The chemical elements are distinguished from each other by the number of protons that are in their atoms.
By this time the Ernest Rutherford model of the atom had been published, [21] [22] but much of the discussion involving atomic structure revolved around the quantum model of Arthur Haas in 1910. Also, at the Solvay Congress in 1911 Hendrik Lorentz suggested after Einstein's talk on quantum structure that the energy of a rotator be set equal to nhv.
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. Sommerfeld argued that if electronic orbits ...
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.