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Sharp Series
The sharp series is a series of spectral lines in the atomic emission spectrum caused when electrons descend from higher-energy s orbitals of an atom to the lowest available p orbital. The spectral lines include some in the visible light, and they extend into the ultraviolet. The lines get closer and closer together as the frequency increases never exceeding the series limit. The sharp series was important in the development of the understanding of electron shells and subshells in atoms. The sharp series has given the letter ''s'' to the s atomic orbital or subshell. The sharp series has a limit given by v=\frac-\frac \text m=2,3,4,5,6,... The series is caused by transitions to the lowest P state from higher energy S orbitals. One terminology to identify the lines is: 1P-mS But note that 1P just means the lowest P state in an atom and that the modern designation would start at 2P, and is larger for higher atomic numbered atoms. The terms can have different designations, mS for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carl Runge
Carl David Tolmé Runge (; 30 August 1856 – 3 January 1927) was a German mathematician, physicist, and spectroscopist. He was co-developer and co-eponym of the Runge–Kutta method (German pronunciation: ), in the field of what is today known as numerical analysis. Life and work Runge spent the first few years of his life in Havana, where his father Julius Runge was the Danish consul. His mother was Fanny Schwartz Tolmé. The family later moved to Bremen, where his father died early (in 1864). In 1880, he received his Ph.D. in mathematics at Berlin, where he studied under Karl Weierstrass. In 1886, he became a professor at the Technische Hochschule Hannover in Hanover, Germany. His interests included mathematics, spectroscopy, geodesy, and astrophysics. In addition to pure mathematics, he did experimental work studying spectral lines of various elements (together with Heinrich Kayser), and was very interested in the application of this work to astronomical spectroscopy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spectral Line
A spectral line is a dark or bright line in an otherwise uniform and continuous spectrum, resulting from emission or absorption of light in a narrow frequency range, compared with the nearby frequencies. Spectral lines are often used to identify atoms and molecules. These "fingerprints" can be compared to the previously collected ones of atoms and molecules, and are thus used to identify the atomic and molecular components of stars and planets, which would otherwise be impossible. Types of line spectra Spectral lines are the result of interaction between a quantum system (usually atoms, but sometimes molecules or atomic nuclei) and a single photon. When a photon has about the right amount of energy (which is connected to its frequency) to allow a change in the energy state of the system (in the case of an atom this is usually an electron changing orbitals), the photon is absorbed. Then the energy will be spontaneously re-emitted, either as one photon at the same frequenc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alkali Metal
The alkali metals consist of the chemical elements lithium (Li), sodium (Na), potassium (K),The symbols Na and K for sodium and potassium are derived from their Latin names, ''natrium'' and ''kalium''; these are still the origins of the names for the elements in some languages, such as German and Russian. rubidium (Rb), caesium (Cs), and francium (Fr). Together with hydrogen they constitute Group (periodic table)#Group names, group 1, which lies in the s-block of the periodic table. All alkali metals have their outermost electron in an atomic orbital, s-orbital: this shared electron configuration results in their having very similar characteristic properties. Indeed, the alkali metals provide the best example of periodic trends, group trends in properties in the periodic table, with elements exhibiting well-characterised homology (chemistry), homologous behaviour. This family of elements is also known as the lithium family after its leading element. The alkali metals are all sh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Friedrich Hund
Friedrich Hermann Hund (4 February 1896 – 31 March 1997) was a German physicist from Karlsruhe known for his work on atoms and molecules. Scientific career Hund worked at the Universities of Rostock, Leipzig, Jena, Frankfurt am Main, and Göttingen. Hund worked with such prestigious physicists as Schrödinger, Dirac, Heisenberg, Max Born, and Walter Bothe. At that time, he was Born's assistant, working with quantum interpretation of band spectra of diatomic molecules. After his studies of mathematics, physics, and geography in Marburg and Göttingen, he worked as a private lecturer for theoretical physics in Göttingen (1925), professor in Rostock (1927), Leipzig University (1929), Jena (1946), Frankfurt/Main (1951) and from 1957 again in Göttingen. Additionally, he stayed in Copenhagen (1926) with Niels Bohr and lectured on the atom at Harvard University (1928). He published more than 250 papers and essays in total. Hund made pivotal contributions to quantum theory - esp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Johannes Rydberg
Johannes (Janne) Robert Rydberg (; 8 November 1854 – 28 December 1919) was a Swedish physicist mainly known for devising the Rydberg formula, in 1888, which is used to describe the wavelengths of photons (of visible light and other electromagnetic radiation) emitted by changes in the energy level of an electron in a hydrogen atom. Biography Rydberg was born 8 November 1854 in Halmstad in southern Sweden, the only child of Sven Rydberg and Maria Anderson Rydberg. When he was 4 years old his father died, and the family was forced to live on a small income. In 1873 he graduated from Halmstads elementärläroverk, where he received high grades in maths and physics. Later that year he enrolled in Lund University, and two years later he was awarded his bachelor's degree. In 1879 he was awarded his Doctor of Philosophy with his dissertation "Konstruktioner af kägelsnitt i 3- och 4-punktskontakt". Rydberg began his career as an amanuensis in the institution. He became a docent i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heinrich Kayser
Heinrich Gustav Johannes Kayser ForMemRS (; 16 March 1853 – 14 October 1940) was a German physicist and spectroscopist. Biography Kayser was born at Bingen am Rhein. Kayser's early work was concerned with the characteristics of acoustic waves. He discovered the occurrence of helium in the Earth's atmosphere in 1868 during a solar eclipse when he detected a new spectral line in the solar spectrum. In 1881 Kayser coined the word “adsorption”. Together with Carl Runge, he examined the spectra of chemical elements. In 1905, he wrote a paper on electron theory.Kayser, Heinrich. (1905). Die elektronentheorie. DC Heath & Company. The kayser unit, associated with wavenumber, of the CGS system was named after him. He died at Bonn The federal city of Bonn ( lat, Bonna) is a city on the banks of the Rhine in the German state of North Rhine-Westphalia, with a population of over 300,000. About south-southeast of Cologne, Bonn is in the southernmost part of the Rhine-Ru ... ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helium II
Helium (from el, ἥλιος, helios, lit=sun) is a chemical element with the symbol He and atomic number 2. It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas and the first in the noble gas group in the periodic table. Its boiling and melting point are the lowest among all the elements. It is the second lightest and second most abundant element in the observable universe (hydrogen is the lightest and most abundant). It is present at about 24% of the total elemental mass, which is more than 12 times the mass of all the heavier elements combined. Its abundance is similar to this in both the Sun and in Jupiter, due to the very high nuclear binding energy (per nucleon) of helium-4, with respect to the next three elements after helium. This helium-4 binding energy also accounts for why it is a product of both nuclear fusion and radioactive decay. The most common isotope of helium in the universe is helium-4, the vast majority of which was formed during the Big ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ζ Puppis
Zeta Puppis (ζ Puppis, abbreviated Zeta Pup, ζ Pup), formally named Naos , is a star in the constellation of Puppis. The spectral class of O4 means this is one of the hottest, and most luminous, stars visible to the naked eye. It is one of the sky's few naked-eye class O-type stars as well as one of the closest to Earth. It is a blue supergiant, one of the most luminous stars in the Milky Way. Visually it is over 10,000 times brighter than the Sun, but its high temperature means that most of its radiation is in the ultraviolet and its bolometric luminosity is over 500,000 times that of the Sun. It is also the 72nd brightest star in terms of apparent magnitude from Earth. It is a runaway star, meaning it has an unusually large pace velocity, probably caused by being ejected from a close binary system when its companion exploded as a supernova. Naos is typical of O-type stars in having an extremely strong stellar wind, measured at 2,500 km/s, w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Edward C
Edward is an English given name. It is derived from the Anglo-Saxon name ''Ēadweard'', composed of the elements '' ēad'' "wealth, fortune; prosperous" and '' weard'' "guardian, protector”. History The name Edward was very popular in Anglo-Saxon England, but the rule of the Norman and Plantagenet dynasties had effectively ended its use amongst the upper classes. The popularity of the name was revived when Henry III named his firstborn son, the future Edward I, as part of his efforts to promote a cult around Edward the Confessor, for whom Henry had a deep admiration. Variant forms The name has been adopted in the Iberian peninsula since the 15th century, due to Edward, King of Portugal, whose mother was English. The Spanish/Portuguese forms of the name are Eduardo and Duarte. Other variant forms include French Édouard, Italian Edoardo and Odoardo, German, Dutch, Czech and Romanian Eduard and Scandinavian Edvard. Short forms include Ed, Eddy, Eddie, Ted, Teddy and Ned. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CRC Press
The CRC Press, LLC is an American publishing group that specializes in producing technical books. Many of their books relate to engineering, science and mathematics. Their scope also includes books on business, forensics and information technology. CRC Press is now a division of Taylor & Francis, itself a subsidiary of Informa. History The CRC Press was founded as the Chemical Rubber Company (CRC) in 1903 by brothers Arthur, Leo and Emanuel Friedman in Cleveland, Ohio, based on an earlier enterprise by Arthur, who had begun selling rubber laboratory aprons in 1900. The company gradually expanded to include sales of laboratory equipment to chemists. In 1913 the CRC offered a short (116-page) manual called the ''Rubber Handbook'' as an incentive for any purchase of a dozen aprons. Since then the ''Rubber Handbook'' has evolved into the CRC's flagship book, the '' CRC Handbook of Chemistry and Physics''. In 1964, Chemical Rubber decided to focus on its publishing ventures ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Group 3 Element
Group 3 is the first group of transition metals in the periodic table. This group is closely related to the rare-earth elements. Although some controversy exists regarding the composition and placement of this group, it is generally agreed among those who study the matter that this group contains the four elements scandium (Sc), yttrium (Y), lutetium (Lu), and lawrencium (Lr); this composition has also been suggested by a 2021 IUPAC provisional report studying the problem. The group is also called the scandium group or scandium family after its lightest member. The chemistry of the group 3 elements is typical for early transition metals: they all essentially have only the group oxidation state of +3 as a major one, and like the preceding main-group metals are quite electropositive and have a less rich coordination chemistry. Due to the effects of the lanthanide contraction, yttrium and lutetium are very similar in properties. Yttrium and lutetium have essentially the chemistry of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alkaline Earth Metal
The alkaline earth metals are six chemical elements in group 2 of the periodic table. They are beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra).. The elements have very similar properties: they are all shiny, silvery-white, somewhat reactive metals at standard temperature and pressure. Structurally, they (together with helium) have in common an outer s-orbital which is full; that is, this orbital contains its full complement of two electrons, which the alkaline earth metals readily lose to form cations with charge +2, and an oxidation state of +2. All the discovered alkaline earth metals occur in nature, although radium occurs only through the decay chain of uranium and thorium and not as a primordial element. There have been experiments, all unsuccessful, to try to synthesize element 120, the next potential member of the group. Characteristics Chemical As with other groups, the members of this family show patterns in their ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
