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Sommerfeld–Kossel Displacement Law
The Sommerfeld–Kossel displacement law states that the first spark (singly ionized) spectrum of an element is similar in all details to the arc (neutral) spectrum of the element preceding it in the periodic table. Likewise, the second (doubly ionized) spark spectrum of an element is similar in all details to the first (singly ionized) spark spectrum of the element preceding it, or to the arc (neutral) spectrum of the element with atomic number two less, and so forth.Herzberg, 1945, p. 81. Hence, the spectra of C I (neutral carbon), N II (singly ionized nitrogen), and O III (doubly ionized oxygen) atoms are similar, apart from shifts of the spectra to shorter wavelengths. C I, N II, and O III all have the same number of electrons, six, and the same ground-state electron configuration: :1s^2\, 2s^2\, 2p^2\, ^3P_0\,. The law was discovered by and named after Arnold Sommerfeld Arnold Johannes Wilhelm Sommerfeld, (; 5 December 1868 – 26 April 1951) was a German theoretical p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electron Configuration
In atomic physics and quantum chemistry, the electron configuration is the distribution of electrons of an atom or molecule (or other physical structure) in atomic or molecular orbitals. For example, the electron configuration of the neon atom is , meaning that the 1s, 2s and 2p subshells are occupied by 2, 2 and 6 electrons respectively. Electronic configurations describe each electron as moving independently in an orbital, in an average field created by all other orbitals. Mathematically, configurations are described by Slater determinants or configuration state functions. According to the laws of quantum mechanics, for systems with only one electron, a level of energy is associated with each electron configuration and in certain conditions, electrons are able to move from one configuration to another by the emission or absorption of a quantum of energy, in the form of a photon. Knowledge of the electron configuration of different atoms is useful in understanding the structu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arnold Sommerfeld
Arnold Johannes Wilhelm Sommerfeld, (; 5 December 1868 – 26 April 1951) was a German theoretical physicist who pioneered developments in atomic and quantum physics, and also educated and mentored many students for the new era of theoretical physics. He served as doctoral supervisor for many Nobel Prize winners in physics and chemistry (only J. J. Thomson's record of mentorship is comparable to his). He introduced the second quantum number (azimuthal quantum number) and the third quantum number (magnetic quantum number). He also introduced the fine-structure constant and pioneered X-ray wave theory. Early life and education Sommerfeld was born in 1868 to a family with deep ancestral roots in Prussia. His mother Cäcilie Matthias (1839–1902) was the daughter of a Potsdam builder. His father Franz Sommerfeld (1820–1906) was a physician from a leading family in Königsberg, where Arnold's grandfather had resettled from the hinterland in 1822 for a career as Court Postal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Walther Kossel
Walther Ludwig Julius Kossel (4 January 1888 – 22 May 1956) was a German physicist known for his theory of the chemical bond (ionic bond/octet rule), Sommerfeld–Kossel displacement law of atomic spectra, the Kossel-Stranski model for crystal growth, and the Kossel effect. Walther was the son of Albrecht Kossel who won the Nobel Prize in Physiology or Medicine in 1910. Career Kossel was born in Berlin, and began studies at the University of Heidelberg in 1906, but was at the University of Berlin during 1907 and 1908. In 1910, he became assistant to Philipp Lenard, who was also his thesis advisor. Kossel was awarded his Ph.D. in 1910, and he stayed on as assistant to Leonard until 1913. In 1913, the year in which Niels Bohr introduced the Bohr model of the atom, Kossel went to the University of Munich as assistant to Arnold Sommerfeld, under whom he did his Habilitation. Under Sommerfeld, Munich was a theoretical center for the developing atomic theory, especially from the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gerhard Herzberg
Gerhard Heinrich Friedrich Otto Julius Herzberg, (; December 25, 1904 – March 3, 1999) was a German-Canadian pioneering physicist and physical chemist, who won the Nobel Prize for Chemistry in 1971, "for his contributions to the knowledge of electronic structure and geometry of molecules, particularly free radicals". Herzberg's main work concerned atomic and molecular spectroscopy. He is well known for using these techniques that determine the structures of diatomic and polyatomic molecules, including free radicals which are difficult to investigate in any other way, and for the chemical analysis of astronomical objects. Herzberg served as Chancellor of Carleton University in Ottawa, Ontario, Canada from 1973 to 1980. Early life and family Herzberg was born in Hamburg, Germany on December 25, 1904 to Albin H. Herzberg and Ella Biber. He had an older brother, Walter, who was born in January 1904. Herzberg started Vorschule (pre-school) late, after contracting measles. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jagdish Mehra
Jagdish Mehra (April 8, 1931 – September 14, 2008) was an Indian-American historian of science. Academic career Mehra was educated at Allahabad University, the Max Planck Institut für Physik and the University of California at Los Angeles and obtained a Ph.D. in theoretical physics at the University of Neuchatel. He subsequently taught at Purdue University, Southeastern Massachusetts University, the University of Geneva, the Solvay Institute in Brussels, Rice University, the University of Houston and the International Center for Theoretical Physics. He is particularly well known for a book in 6 volumes on The Historical Development of Quantum Theory,Mehra, J. and Rechenberg, H. The Historical Development of Quantum Theory, Volumes 1-6. New York: Springer-Verlag which he wrote with Helmut Rechenberg. He also wrote a biography of Richard Feynman. He also wrote a book on the controversy surrounding the exact role David Hilbert played in the development of the gravitation th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helmut Rechenberg
Helmut Rechenberg (born November 6, 1937, in Berlin; died November 10, 2016, in Munich) was a German physicist and science historian. Rechenberg studied mathematics, physics and astronomy at the University of Munich and graduated in 1964. At Munich, his work was in experimental physics, studying the magnetism of solids. He moved to the Max Planck Institute for Physics in Munich, where he became Werner Heisenberg's doctoral student. In 1968, he graduated with a doctorate on quantum field theory. From 1970 to 1972 he worked at the University of Texas at Austin, collaborating with George Sudarshan on quantum field theory and with Jagdish Mehra on science history. He then returned to Germany and the Max Planck Institute, from which he officially retired in 2002. His six-volume work with Jagdish Mehra on the history of quantum mechanics has been described as "an extraordinary amount of painstaking scholarship". Rechenberg also co-edited Werner Heisenberg's collected works and from 19 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atomic Physics
Atomic physics is the field of physics that studies atoms as an isolated system of electrons and an atomic nucleus. Atomic physics typically refers to the study of atomic structure and the interaction between atoms. It is primarily concerned with the way in which electrons are arranged around the nucleus and the processes by which these arrangements change. This comprises ions, neutral atoms and, unless otherwise stated, it can be assumed that the term ''atom'' includes ions. The term ''atomic physics'' can be associated with nuclear power and nuclear weapons, due to the synonymous use of ''atomic'' and ''nuclear'' in standard English. Physicists distinguish between atomic physics—which deals with the atom as a system consisting of a nucleus and electrons—and nuclear physics, which studies nuclear reactions and special properties of atomic nuclei. As with many scientific fields, strict delineation can be highly contrived and atomic physics is often considered in the wider c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quantum Mechanics
Quantum mechanics is a fundamental theory in physics that provides a description of the physical properties of nature at the scale of atoms and subatomic particles. It is the foundation of all quantum physics including quantum chemistry, quantum field theory, quantum technology, and quantum information science. Classical physics, the collection of theories that existed before the advent of quantum mechanics, describes many aspects of nature at an ordinary (macroscopic) scale, but is not sufficient for describing them at small (atomic and subatomic) scales. Most theories in classical physics can be derived from quantum mechanics as an approximation valid at large (macroscopic) scale. Quantum mechanics differs from classical physics in that energy, momentum, angular momentum, and other quantities of a bound system are restricted to discrete values ( quantization); objects have characteristics of both particles and waves (wave–particle duality); and there are limits to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
