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Bema Hapothle
In chemistry, Bema Hapothle is an extended acronym for Bell–Marcus– Hammond– Polanyi–Thornton– Leffler, referring to the combined contribution of the theories of these chemists to the rationalization of changes in transition state structure to perturbations, such as change of reaction solvent A solvent (s) (from the Latin '' solvō'', "loosen, untie, solve") is a substance that dissolves a solute, resulting in a solution. A solvent is usually a liquid but can also be a solid, a gas, or a supercritical fluid. Water is a solvent for .... See also * Hammond–Leffler postulate References Physical organic chemistry {{chem-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemistry
Chemistry is the scientific study of the properties and behavior of matter. It is a natural science that covers the elements that make up matter to the compounds made of atoms, molecules and ions: their composition, structure, properties, behavior and the changes they undergo during a reaction with other substances. Chemistry also addresses the nature of chemical bonds in chemical compounds. In the scope of its subject, chemistry occupies an intermediate position between physics and biology. It is sometimes called the central science because it provides a foundation for understanding both basic and applied scientific disciplines at a fundamental level. For example, chemistry explains aspects of plant growth ( botany), the formation of igneous rocks ( geology), how atmospheric ozone is formed and how environmental pollutants are degraded ( ecology), the properties of the soil on the moon ( cosmochemistry), how medications work (pharmacology), and how to collect DNA ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acronym
An acronym is a word or name formed from the initial components of a longer name or phrase. Acronyms are usually formed from the initial letters of words, as in '' NATO'' (''North Atlantic Treaty Organization''), but sometimes use syllables, as in '' Benelux'' (short for ''Belgium, the Netherlands, and Luxembourg''). They can also be a mixture, as in '' radar'' (''Radio Detection And Ranging''). Acronyms can be pronounced as words, like '' NASA'' and '' UNESCO''; as individual letters, like ''FBI'', '' TNT'', and ''ATM''; or as both letters and words, like ''JPEG'' (pronounced ') and ''IUPAC''. Some are not universally pronounced one way or the other and it depends on the speaker's preference or the context in which it is being used, such as '' SQL'' (either "sequel" or "ess-cue-el"). The broader sense of ''acronym''—the meaning of which includes terms pronounced as letters—is sometimes criticized, but it is the term's original meaning and is in common use. Dictionary ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ronnie Bell
Ronald Percy Bell FRS FRSC FRSE (24 November 1907 – 9 January 1996) was a leading British physical chemist who worked in the Physical Chemistry Laboratory at the University of Oxford. Life Ronald Percy Bell was the eldest child of Edwin Alfred Bell and his wife Beatrice Annie (née Ash), teachers at an elementary school. He was born on 24 November 1907 at Willowfield, Court House Road, Maidenhead; he had a brother, Kenneth, and an adopted sister, Margaret. From age 11 Bell attended Maidenhead County Boys’ School, where F. Sherwood Taylor was chemistry master, and a great influence on Bell; from there he went up to Balliol to read chemistry in 1924. Bell obtained a first-class honours degree in 1928. Unusually, he published two papers as sole author in his final year. Bell was awarded an Oxford University senior studentship in 1928 to work with Brønsted in Copenhagen, and in 1930 the Goldsmiths' Company gave him a senior studentship, enabling him to work on the th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rudolph A
Rudolph or Rudolf may refer to: People * Rudolph (name), the given name including a list of people with the name Religious figures * Rudolf of Fulda (died 865), 9th century monk, writer and theologian * Rudolf von Habsburg-Lothringen (1788–1831), Archbishop of Olomouc and member of the House of Habsburg-Lorraine Royalty and nobility * Rudolph I (other) *Rudolph II (other) * Rudolph III (other) * Rudolph of France (died 936) * Rudolph I of Germany (1218–1291) * Rudolf II, Holy Roman Emperor (1552–1612) * Rudolph, Prince of Anhalt-Zerbst (1576–1621) * Rudolf, Crown Prince of Austria (1858–1889), son and heir of Emperor Franz Joseph I of Austria and Empress Elisabeth of Austria (died at Mayerling) Places * Rudolph Glacier, Antarctica * Rudolph, South Dakota, US * Rudolph, Wisconsin, US, a village * Rudolph (town), Wisconsin, adjacent to the village * Rudolf Island, northernmost island of Europe * Lake Rudolf, now Lake Turkana, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
George S
George may refer to: People * George (given name) * George (surname) * George (singer), American-Canadian singer George Nozuka, known by the mononym George * George Washington, First President of the United States * George W. Bush, 43rd President of the United States * George H. W. Bush, 41st President of the United States * George V, King of Great Britain, Ireland, the British Dominions and Emperor of India from 1910-1936 * George VI, King of Great Britain, Ireland, the British Dominions and Emperor of India from 1936-1952 * Prince George of Wales * George Papagheorghe also known as Jorge / GEØRGE * George, stage name of Giorgio Moroder * George Harrison, an English musician and singer-songwriter Places South Africa * George, Western Cape ** George Airport United States * George, Iowa * George, Missouri * George, Washington * George County, Mississippi * George Air Force Base, a former U.S. Air Force base located in California Characters * George (Peppa Pig), ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Michael Polanyi
Michael Polanyi (; hu, Polányi Mihály; 11 March 1891 – 22 February 1976) was a Hungarian-British polymath, who made important theoretical contributions to physical chemistry, economics, and philosophy. He argued that positivism supplies an imperfect account of knowing as no observer is perfectly impartial. His wide-ranging research in physical science included chemical kinetics, x-ray diffraction, and adsorption of gases. He pioneered the theory of fibre diffraction analysis in 1921, and the dislocation theory of plastic deformation of ductile metals and other materials in 1934. He immigrated to Germany, in 1926 becoming a chemistry professor at the Kaiser Wilhelm Institute in Berlin, and then in 1933 to England, becoming first a chemistry professor, and then a social sciences professor at the University of Manchester. Two of his pupils, and his son John Charles Polanyi won Nobel Prizes in Chemistry. In 1944 Polanyi was elected to the Royal Society. The contributi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Edward R
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 an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John E
John is a common English name and surname: * John (given name) * John (surname) John may also refer to: New Testament Works * Gospel of John, a title often shortened to John * First Epistle of John, often shortened to 1 John * Second Epistle of John, often shortened to 2 John * Third Epistle of John, often shortened to 3 John People * John the Baptist (died c. AD 30), regarded as a prophet and the forerunner of Jesus Christ * John the Apostle (lived c. AD 30), one of the twelve apostles of Jesus * John the Evangelist, assigned author of the Fourth Gospel, once identified with the Apostle * John of Patmos, also known as John the Divine or John the Revelator, the author of the Book of Revelation, once identified with the Apostle * John the Presbyter, a figure either identified with or distinguished from the Apostle, the Evangelist and John of Patmos Other people with the given name Religious figures * John, father of Andrew the Apostle Andrew the Ap ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transition State
In chemistry, the transition state of a chemical reaction is a particular configuration along the reaction coordinate. It is defined as the state corresponding to the highest potential energy along this reaction coordinate. It is often marked with the double dagger ‡ symbol. As an example, the transition state shown below occurs during the SN2 reaction of bromoethane with a hydroxide anion: The activated complex of a reaction can refer to either the transition state or to other states along the reaction coordinate between reactants and products, especially those close to the transition state. Peter Atkins and Julio de Paula, ''Physical Chemistry'' (8th ed., W.H. Freeman 2006), p.809 According to the transition state theory, once the reactants have passed through the transition state configuration, they always continue to form products. History of concept The concept of a transition state has been important in many theories of the rates at which chemical react ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solvent
A solvent (s) (from the Latin '' solvō'', "loosen, untie, solve") is a substance that dissolves a solute, resulting in a solution. A solvent is usually a liquid but can also be a solid, a gas, or a supercritical fluid. Water is a solvent for polar molecules and the most common solvent used by living things; all the ions and proteins in a cell are dissolved in water within the cell. The quantity of solute that can dissolve in a specific volume of solvent varies with temperature. Major uses of solvents are in paints, paint removers, inks, and dry cleaning. Specific uses for organic Organic may refer to: * Organic, of or relating to an organism, a living entity * Organic, of or relating to an anatomical organ Chemistry * Organic matter, matter that has come from a once-living organism, is capable of decay or is the product ... solvents are in dry cleaning (e.g. tetrachloroethylene); as paint thinners ( toluene, turpentine); as nail polish removers and solvents of glue ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chem
Chem may refer to: * Chemistry practical waali mam * Chemistry *Chemical * ''Chem'' (journal), a scientific journal published by Cell Press *Post apocalyptic slang for "drugs", medicinal or otherwise in the Fallout video game series. In Ancient Egyptian usage: * ''Khem'' (also spelt ''Chem''), the Egyptian word for "black" *Min (god), in the past erroneously named ''Khem'' CHEM may refer to : *A metabolic panel: for instance, CHEM-7, which is the basic metabolic panel * CHEM-DT, a Canadian television channel See also *Chemo (other) Chemo is a prefix meaning ''chemical'' and commonly used as an abbreviation for chemotherapy. Chemo may also refer to: People * Chemo (musician), an English musician now known as Forest DLG * Chemo Soto, a Puerto Rican politician * José del Sol ... * Kemi, a place in Finland {{disambig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hammond–Leffler Postulate
Hammond's postulate (or alternatively the Hammond–Leffler postulate), is a hypothesis in physical organic chemistry which describes the geometric structure of the transition state in an organic chemical reaction. First proposed by George Hammond in 1955, the postulate states that: If two states, as, for example, a transition state and an unstable intermediate, occur consecutively during a reaction process and have nearly the same energy content, their interconversion will involve only a small reorganization of the molecular structures. Therefore, the geometric structure of a state can be predicted by comparing its energy to the species neighboring it along the reaction coordinate. For example, in an ''exothermic'' reaction the transition state is closer in energy to the reactants than to the products. Therefore, the transition state will be more geometrically similar to the reactants than to the products. In contrast, however, in an ''endothermic'' reaction the transition st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
