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Hydrogen Isotope Biogeochemistry
Hydrogen isotope biogeochemistry is the scientific study of biological, geological, and chemical processes in the environment using the distribution and relative abundance of hydrogen isotopes. There are two stable isotopes of hydrogen, protium 1H and deuterium 2H, which vary in relative abundance on the order of hundreds of permil. The ratio between these two species can be considered the hydrogen isotopic fingerprint of a substance. Understanding isotopic fingerprints and the sources of fractionation that lead to variation between them can be applied to address a diverse array of questions ranging from ecology and hydrology to geochemistry and paleoclimate reconstructions. Since specialized techniques are required to measure natural hydrogen isotope abundance ratios, the field of hydrogen isotope biogeochemistry provides uniquely specialized tools to more traditional fields like ecology and geochemistry. History of hydrogen isotopes Earliest work The study of hydrogen stable ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrogen Isotopes
Hydrogen (1H) has three naturally occurring Isotope, isotopes, sometimes denoted , , and . and are stable, while has a half-life of years. Heavier isotopes also exist, all of which are synthetic and have a half-life of less than one Orders of magnitude (time)#Zeptosecond, zeptosecond (10−21 s). Of these, is the least stable, while is the most. Hydrogen is the only chemical element, element whose isotopes have different names that remain in common use today: the (or hydrogen-2) isotope is deuterium and the (or hydrogen-3) isotope is tritium. The symbols D and T are sometimes used for deuterium and tritium. The International Union of Pure and Applied Chemistry, IUPAC accepts the D and T symbols, but recommends using standard isotopic symbols ( and ) instead to avoid confusion in the alphabetic sorting of Chemical formula, chemical formulas. The isotope , with no Neutron, neutrons, is sometimes called Hydrogen atom, protium. (During the early study of radioactivity, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Balmer Series
The Balmer series, or Balmer lines in atomic physics, is one of a set of six named series describing the spectral line emissions of the hydrogen atom. The Balmer series is calculated using the Balmer formula, an empirical equation discovered by Johann Balmer in 1885. The visible spectrum of light from hydrogen displays four wavelengths, 410 nm, 434 nm, 486 nm, and 656 nm, that correspond to emissions of photons by electrons in excited states transitioning to the quantum level described by the principal quantum number ''n'' equals 2. There are several prominent ultraviolet Balmer lines with wavelengths shorter than 400 nm. The number of these lines is an infinite continuum as it approaches a limit of 364.5 nm in the ultraviolet. After Balmer's discovery, five other hydrogen spectral series were discovered, corresponding to electrons transitioning to values of ''n'' other than two . Overview The Balmer series is characterized by the electron t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposing military alliances: the Allies and the Axis powers. World War II was a total war that directly involved more than 100 million personnel from more than 30 countries. The major participants in the war threw their entire economic, industrial, and scientific capabilities behind the war effort, blurring the distinction between civilian and military resources. Aircraft played a major role in the conflict, enabling the strategic bombing of population centres and deploying the only two nuclear weapons ever used in war. World War II was by far the deadliest conflict in human history; it resulted in 70 to 85 million fatalities, mostly among civilians. Tens of millions died due to genocides (including the Holocaust), starvation, ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Robert Cornog
Robert Alden Cornog (July 7, 1912 – July 17, 1998) was a physicist and engineer who helped develop the atomic bomb and missile systems, and made significant discoveries regarding isotopes of hydrogen and helium. A native of Portland, Oregon, who grew up in Iowa City, Cornog earned a bachelor's degree in mechanical engineering at the University of Iowa. After working for the United States Bureau of Reclamation on the Boulder Dam design, he studied at UC Berkeley for his doctorate in physics. His graduate student research led to the co-discovery, with Luis Alvarez, that hydrogen of atomic mass 3 (tritium) was radioactive, and that helium of mass 3 helium-3) occurs in nature. He also assisted Emilio Segrè in the discovery of element 85, astatine. During World War II, Cornog designed magnetic equipment for ships and went to work on the Manhattan Project, successively at UC Berkeley, Princeton University and in Los Alamos, New Mexico. Cornog became chief engineer of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Luis Walter Alvarez
Luis Walter Alvarez (June 13, 1911 – September 1, 1988) was an American experimental physicist, inventor, and professor who was awarded the Nobel Prize in Physics in 1968 for his discovery of resonance states in particle physics using the hydrogen bubble chamber. In 2007 the ''American Journal of Physics'' commented, "Luis Alvarez was one of the most brilliant and productive experimental physicists of the twentieth century." After receiving his PhD from the University of Chicago in 1936, Alvarez went to work for Ernest Lawrence at the Radiation Laboratory at the University of California, Berkeley. Alvarez devised a set of experiments to observe K-electron capture in radioactive nuclei, predicted by the beta decay theory but never before observed. He produced tritium using the cyclotron and measured its lifetime. In collaboration with Felix Bloch, he measured the magnetic moment of the neutron. In 1940, Alvarez joined the MIT Radiation Laboratory, where he contributed to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gilbert N Lewis
Gilbert Newton Lewis (October 23 or October 25, 1875 – March 23, 1946) was an American physical chemist and a Dean of the College of Chemistry at University of California, Berkeley. Lewis was best known for his discovery of the covalent bond and his concept of electron pairs; his Lewis dot structures and other contributions to valence bond theory have shaped modern theories of chemical bonding. Lewis successfully contributed to chemical thermodynamics, photochemistry, and isotope separation, and is also known for his concept of acids and bases. Lewis also researched on relativity and quantum physics, and in 1926 he coined the term "photon" for the smallest unit of radiant energy. G. N. Lewis was born in 1875 in Weymouth, Massachusetts. After receiving his PhD in chemistry from Harvard University and studying abroad in Germany and the Philippines, Lewis moved to California in 1912 to teach chemistry at the University of California, Berkeley, where he became the Dean of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
UC Berkeley
The University of California, Berkeley (UC Berkeley, Berkeley, Cal, or California) is a public university, public land-grant university, land-grant research university in Berkeley, California. Established in 1868 as the University of California, it is the state's first land-grant university and the founding campus of the University of California system. Its fourteen colleges and schools offer over 350 degree programs and enroll some 31,800 undergraduate and 13,200 graduate students. Berkeley ranks among the world's top universities. A founding member of the Association of American Universities, Berkeley hosts many leading research institutes dedicated to science, engineering, and mathematics. The university founded and maintains close relationships with three United States Department of Energy National Laboratories, national laboratories at Lawrence Berkeley National Laboratory, Berkeley, Lawrence Livermore National Laboratory, Livermore and Los Alamos National Laboratory, Los ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tritium
Tritium ( or , ) or hydrogen-3 (symbol T or H) is a rare and radioactive isotope of hydrogen with half-life about 12 years. The nucleus of tritium (t, sometimes called a ''triton'') contains one proton and two neutrons, whereas the nucleus of the common isotope hydrogen-1 (''protium'') contains one proton and zero neutrons, and that of hydrogen-2 (''deuterium'') contains one proton and one neutron. Naturally occurring tritium is extremely rare on Earth. The atmosphere has only trace amounts, formed by the interaction of its gases with cosmic rays. It can be produced artificially by irradiating lithium metal or lithium-bearing ceramic pebbles in a nuclear reactor and is a low-abundance byproduct in normal operations of nuclear reactors. Tritium is used as the energy source in radioluminescent lights for watches, gun sights, numerous instruments and tools, and even novelty items such as self-illuminating key chains. It is used in a medical and scientific setting as a radioacti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paul Harteck
Paul Karl Maria Harteck (20 July 190222 January 1985) was an Austrian physical chemist. In 1945 under Operation Epsilon in "the big sweep" throughout Germany, Harteck was arrested by the allied British and American Armed Forces for suspicion of aiding the Nazis in their nuclear weapons program and he was incarcerated at Farm Hall, an English house fitted with covert electronic listening devices, for six months. Education Harteck studied chemistry at the University of Vienna and the Humboldt University of Berlin from 1921 to 1924. He received his doctorate at the latter under Max Bodenstein in 1926. From 1926 to 1928 he was Arnold Eucken’s teaching assistant at the University of Breslau.Hentschel, 1996, Appendix F; see the entry for Paul Harteck. Career From 1928 to 1933, Harteck was a staff scientist at the KWI für physikalische Chemie und Elektrochemie (KWIPC) ( Kaiser Wilhelm Institute for Physical Chemistry and Elektrochemistry) located in Dahlem-Berlin, where h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mark Oliphant
Sir Marcus Laurence Elwin Oliphant, (8 October 1901 – 14 July 2000) was an Australian physicist and humanitarian who played an important role in the first experimental demonstration of nuclear fusion and in the development of nuclear weapons. Born and raised in Adelaide, South Australia, Oliphant graduated from the University of Adelaide in 1922. He was awarded an 1851 Exhibition Scholarship in 1927 on the strength of the research he had done on mercury, and went to England, where he studied under Sir Ernest Rutherford at the University of Cambridge's Cavendish Laboratory. There, he used a particle accelerator to fire heavy hydrogen nuclei (deuterons) at various targets. He discovered the respective nuclei of helium-3 (helions) and of tritium (tritons). He also discovered that when they reacted with each other, the particles that were released had far more energy than they started with. Energy had been liberated from inside the nucleus, and he realised that this was a resu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ernest Rutherford
Ernest Rutherford, 1st Baron Rutherford of Nelson, (30 August 1871 – 19 October 1937) was a New Zealand physicist who came to be known as the father of nuclear physics. ''Encyclopædia Britannica'' considers him to be the greatest experimentalist since Michael Faraday (1791–1867). Apart from his work in his homeland, he spent a substantial amount of his career abroad, in both Canada and the United Kingdom. In early work, Rutherford discovered the concept of radioactive half-life, the radioactive element radon, and differentiated and named alpha and beta radiation. This work was performed at McGill University in Montreal, Quebec, Canada. It is the basis for the Nobel Prize in Chemistry he was awarded in 1908 "for his investigations into the disintegration of the elements, and the chemistry of radioactive substances", for which he was the first Oceanian Nobel laureate, and the first to perform the awarded work in Canada. In 1904, he was elected as a member to the Am ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Urey
Urey may refer to: People *Benoni Urey (born 1957), Americo-Liberian businessman and politician *Daniel Salamanca Urey (1869–1935), president of Bolivia *Harold Urey (1893-1981), American physical chemist *Urey Fedorovich Lisianski (1773–1837), explorer and officer in the Imperial Russian Navy * Urey Woodson (1859–1939), American politician, and newspaper editor and publisher Other uses * 4716 Urey, a minor planet * Urey (crater), a lunar impact crater * Urey instrument (or Urey: Mars Organic and Oxidant Detector), a developmental spacecraft instrument for detecting organic compounds * Urey Medal, given annually by the European Association of Geochemistry See also * Uri (other) Uri may refer to: Places * Canton of Uri, a canton in Switzerland * Úri, a village and commune in Hungary * Uri, Iran, a village in East Azerbaijan Province * Uri, Jammu and Kashmir, a town in India * Uri (island), an island off Malakula Isla ... * Urie (other) * Ury (disam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
