dablink This article is about nuclear physics. For electroncapture processes in chemistry, see Electroncapture ionization and Electroncapture dissociation . See also Beta decay File Elektroneneinfang 2 Phasen .png thumb ElectroncaptureElectroncapture is a process in which a proton rich nuclide ... state of the new nuclide. Electroncapture is the primary decay mode for isotope s with a relative ... by emitting a positron . Electroncapture also exists as a viable decay mode for radioactive ... to allow it, and thus electroncapture is the sole decay mode. For example, rubidium 83 37 protons, 46 neutrons will decay to krypton 83 36 protons, 47 neutrons solely by electroncapture the energy ... of electroncapture, one of the orbital electron s, usually from the K or L electron shell K electroncapture , also K capture , or L electroncapture , L capture , is captured by a proton ... in electroncapture, the number of neutrons increases by 1, the number of protons decreases by 1, and the atomic mass number remains unchanged. By changing the number of protons, electroncapture ... The theory of electroncapture was first discussed by Gian Carlo Wick in a 1934 paper, and then developed by Hideki Yukawa and others. K electroncapture was first observed by Luis Alvarez , in vanadium ... on line October 7, 2009. ref ref Nuclear K ElectronCapture, Luis W. Alvarez, Physical Review 52 1937 , pp. 134 135, doi 10.1103 PhysRev.52.134 . ref Alvarez went on to study electroncapture in gallium 67 and other nuclides. ref name k ref ElectronCapture and Internal Conversion in Gallium ... are written. Radioactive isotopes that decay by pure electroncapture can, in theory, be inhibited ... on electroncapture. Chemical bonds can also affect the rate of electroncapture to a small degree ..., 375 377 2006 Change of the sup 7 sup Be electroncapture half life in metallic environments ref ... than stable isotopes of the same element tend to decay through beta decay Electroncapture ... more details
Electroncapture ionization is the ionization of a gas phase atom or molecule by attachment of an electron to create an ion of the form A sup sup . The reaction is math A e overset M to A math where the M over the arrow denotes that to conserve energy and momentum a third body is required the molecularity of the reaction is three . Electroncapture can be used in conjunction with chemical ionization . ref Citation doi 10.1021 ac50035a017 title Electroncapture negative ion chemical ionization mass spectrometry year 1978 author Donald F. Hunt Frank W. Crow journal Analytical Chemistry volume 50 issue 13 pages 1781 ref An electroncapture detector is used in some gas chromatography systems. ref GoldBookRef title electroncapture detector in gas chromatography file E01981 ref See also Electroncapture dissociation References Reflist analytical chem stub Category Ion source ... more details
Double electroncapture is a decay mode of atomic nucleus . For a nuclide A , Z with number of nucleon s A and atomic number Z , double electroncapture is only possible if the mass of the nuclide of A , Z 2 is lower. In this mode of decay, two of the orbital electron s are captured by two proton s in the nucleus ... krypton 78 2 SubatomicParticle link yes Electron &rarr Nuclide Link selenium 78 2 SubatomicParticle link yes Electron Neutrino In most cases this decay mode is masked by more probable modes single electroncapture etc. , but when all these modes are forbidden or strongly suppressed, double electroncapture becomes the main mode of decay. There exist 35 naturally occurring isotopes that can undergo double electroncapture. However, there are no confirmed observations of this process. One reason is that the probability of double electroncapture ... is enough to allow another mode of decay electroncapture with positron emission . It occurs simultaneously with double electroncapture, their branching ratio depending on nuclear properties .... Neutrinoless double electroncapture The above described process with capture of two electrons and emission of two neutrinos two neutrino double electroncapture is allowed by the Standard Model ... , another kind of the process can occur the so called neutrinoless double electroncapture. In this case ... &rarr Nuclide Link selenium 78 See also double beta decay beta decay electroncapture neutrino ..., and the atomic mass number A remains unchanged. By changing the number of protons, double electroncapture transforms the nuclide into a new chemical element element . Example Autogenerated using Phykiformulae ... are X ray s and Auger electron s that are emitted by the excited atomic shell. In the range of their energies 1 10 keV , the background is usually high. Thus, the experimental detection of double electroncapture is more difficult than that for double beta decay . If the mass difference between the mother ... more details
Orphan date January 2011 Electroncapture mass spectrometry EC MS is a type of mass spectrometry that uses electroncapture ionization ECI to form negative ion s from chemical compounds with positive electron affinity electron affinities . The approach is particularly effective for electrophile s. In contrast to electron ionization , EC MS uses low energy electrons in a gas discharge . The technique can be used with gas chromatography mass spectrometry . ref name pmid15180565 cite journal author Leis HJ, Fauler G, Rechberger GN, Windischhofer W title Electroncapture mass spectrometry a powerful tool in biomedical trace level analysis journal Curr. Med. Chem. volume 11 issue 12 pages 1585 94 year 2004 month June pmid 15180565 doi url http www.bentham direct.org pages content.php?CMC 2004 00000011 00000012 0005C.SGM ref Mechanism The attachment of a low energy electron can give rise to two possible reactions for the compound, as shown below. Either the compound attaches an electron to form a Radical chemistry radical anion , math AB e to AB bullet math , or the compound fragments, resulting in electroncapture dissociation ECD . ref cite journal last Giese first RW title Electroncapture mass spectrometry recent advances journal Journal of Chromatography volume 892 issue 1 2 pages 329 346 publisher location year 2000 url doi 10.1016 S0021 9673 00 00364 2 pmid 11045497 accessdate ref ECD forms an anion fragment and a radical fragment math AB e to A B bullet math . Fragmentation in ECI has been studied by tandem mass spectrometry . ref name pmid10962492 cite journal author Wei J, Liu S, Fedoreyev SA, Voinov VG title A study of resonance electroncapture ionization on a quadrupole tandem mass spectrometer journal Rapid Commun. Mass Spectrom. volume 14 issue 18 pages 1689 94 year 2000 pmid 10962492 doi 10.1002 1097 0231 20000930 14 18 1689 AID RCM75 3.0.CO 2 G ref See also Electroncapture detector References reflist Category Ion source chemistry stub ... more details
File Electroncapture detector.gif thumb right 200 px Schematic of an electroncapture detector for a gas chromatograph with a sup 63 sup Ni source. An electroncapture detector ECD is a device for detecting atoms and molecules in a gas through the attachment of electrons via electroncapture ionization . The device was invented in 1957 by James Lovelock Dr. James E. Lovelock ref cite journal title A sensitive detector for gas chromatography author J. E. Lovelock journal Journal of Chromatography A year 1958 volume 1 issue 1 pages 35 46 doi 10.1016 S0021 9673 00 93398 3 ref ref cite journal title The electroncapture detector author J.E. Lovelock journal Journal of Chromatography A year 1974 volume 99 issue 1 pages 3 12 doi 10.1016 S0021 9673 00 90840 9 ref and is used in Gas liquid chromatography gas chromatography to detect trace amounts of chemical compounds in a sample. ref cite journal title Selective detectors in gas chromatography author M. Krej i and M. Dressler journal Chromatographic ... journal title Electroncapture detection in gas chromatography author E. D. Pellizzari journal Journal ... ref Gas chromatograph detector The electroncapture detector is used for detecting electron absorbing ... by the Gas chromatography carrier gas , electron absorbing analyte molecules capture electrons ... is thus proportional to the degree of electroncapture. ECD detectors are particularly sensitive ... accessdate 2011 04 21 ref The detection limit for electroncapture detectors is 5 femtograms .... References Reflist Category Measuring instruments ElectronCapture Detector ECD Category Gas ... nl Electroncapture detector pl Detektor wychwytu elektron w ... . The ECD uses a radioactive beta particle electron emitter in conjunction with a so called makeup gas flowing through the detector chamber. The electron emitter typically consists of a metal ... to remove an electron from a nitrogen molecule. The electrons emitted from the electron emitter collide ... more details
Electroncapture dissociation ECD is a method of Fragmentation mass spectrometry fragmenting gas phase ... NL, McLafferty FW title Electroncapture dissociation of multiply charged protein cations. A nonergodic ... ref ref name McLafferty2001 Cite journal last McLafferty first F. year 2001 title Electroncapture ... s lab at Cornell University . Principles Electroncapture dissociation typically involves a multiply protonated molecule M interacting with a free electron to form an odd electron ion math M nH ... JE title Structural characterization of the GM1 ganglioside by infrared multiphoton dissociation, electroncapture dissociation, and electron detachment dissociation electrospray ionization FT ICR MS ... cite journal author Cooper HJ, H kansson K, Marshall AG title The role of electroncapture dissociation ... Toward a general mechanism of electroncapture dissociation journal J. Am. Soc. Mass Spectrom. volume ... initiated by the electron may be responsible for the action of ECD. ref cite journal author Leymarie N, Costello CE, OConnor PB title ElectronCapture Dissociation Initiates a Free Radical Reaction Cascade ... ref ref name pmid16794768 cite journal author Bakhtiar R, Guan Z title Electroncapture dissociation ... also Electroncapture ionization electroncapture mass spectrometry RRKM theory References Reflist ... MS MS fragmentation methods such as electron detachment dissociation electron detachment dissociation ... M, Skurski P, Simons J title Backbone and side chain cleavages in electron detachment dissociation ... TN, Linhardt RJ, Amster IJ title EVALUATION OF THE EXPERIMENTAL PARAMETERS WHICH CONTROL ELECTRON ... RA title C alpha C backbone fragmentation dominates in electron detachment dissociation of gas phase ... on the electron detachment dissociation and infrared multiphoton dissociation of glycosaminoglycan oligosaccharides ... author Savitski MM, Kjeldsen F, Nielsen ML, Zubarev RA title Complementary sequence preferences of electroncapture dissociation and vibrational excitation in fragmentation of polypeptide polycations ... more details
into single line entries. Infobox Particle name Electron image File Crookes tube in use lateral view standing cross prPNr 11.jpg 280px alt A glass tube containing a glowing green electron beam caption ... Rays A History of J J Thomson s Electron url http books.google.com ?id xUzaWGocMdMC&printsec ... Warwick first2 A. year 2001 title Histories of the Electron The Birth of Microphysics url http ... 44 page 293 ref symbol SubatomicParticle Electron , SubatomicParticle beta mass val 9.10938291 ... electric charge val 1 el e ref group note The electron s charge is the negative of elementary ... Bohr magneton sub B sub ref name 2010 CODATA spin frac 1 2 The electron symbol SubatomicParticle Electron is a subatomic particle with a negative elementary charge elementary electric charge . It has ... . ref name prl50 An electron has a rest mass mass that is approximately Proton to electron mass ... spin of the electron is a half integer value in units of reduced Planck constant , which means that it is a fermion . The antiparticle of the electron is called the positron it is identical to the electron .... When an electron collides with a positron, both particles may either Bhabha scattering scatter off ... in experiments with electrons, due to their tiny mass. Since an electron is a fermion, no two electrons ... Laming ref name arabatzis the name electron was introduced for this charge in 1894 by Irish physicist George Johnstone Stoney . The electron was identified as a particle in 1897 by J. J. Thomson and his ... , electrons play an essential role. An electron in motion relative to an observer generates a magnetic field , and will be deflected by external magnetic fields. When an electron is accelerated, it can ... to an atom s total mass. The attractive Coulomb s law Coulomb force between an electron and a proton ... of containing and observing individual electrons as well as Plasma physics electron plasma , whereas dedicated telescope s can detect electron plasma in outer space. Electrons have many applications ... more details
The Capture Guardians of Ga Hoole The Capture Animorphs Animorphs Book 6 The Capture , a novel by K.A. Applegate The Capture film The Capture film , a 1950 film starring Lew Ayres and Teresa Wright The Capture , a humorous slideshow written by Robert Asprin and illustrated by Phil Foglio, nominated for the 1976 Hugo Award for Best Dramatic Presentation Guardians of Ga Hoole The Capture Guardians of Ga Hoole Book 1 The Capture , a novel by Kathryn Lasky See also Capture disambiguation disambig Guardians of Ga Hoole The Capture by Kathryn Lasky ... more details
Wiktionary Capture may refer to Capture chess , to remove the opponent s piece from the board by taking it with one s own piece Capture politics , situations in which a government agency created to act in the public interest instead acts in favor of other interests Capture rivers , a geomorphological phenomenon occurring when a stream or river is diverted from its own bed FM capture , a phenomenon in which only the stronger of two signals near the same FM frequency will be demodulated Motion capture , the process of recording movement and translating that movement onto a digital model Schematic capture , a step in electronic design automation at which the electronic schematic is created by a designer Capture CIS , a software tool used for circuit schematic capture Screen capture disambiguation , an image taken by the computer to record the visible items Video capture , the process of converting an analog video signal to digital form Capture fishery , a wild fishery in which the aquatic life is not controlled and needs to be captured or fished Rule of capture , common law that determines ownership of captured natural resources including groundwater, oil, gas and game animals disambig es Captura fr Capture ko ru ... more details
Electron wake is the disturbance left after a high energy charged particle passes through condensed matter or plasma. Ions passing through can introduce periodic oscillations in the crystal lattice or plasma wave with the characteristic frequency of the crystal or plasma frequency . Interactions of the field created by these oscillations with the charged particle field alternate from constructive interference to destructive interference , producing alternating waves of electric field and displacement. The frequency of the wake field is determined by the nature of the penetrated matter, and the period of the wake field is directly proportional to the speed of the incoming charged particle. The amplitude of the first wake wave is the most important, as it produces a braking force on the charged particle, eventually slowing it down. Wake fields also can capture and guide light ions or positrons in the direction perpendicular to the wake. The larger the speed of the original charged particle, the larger the angle between the initial particle s velocity and the captured ion s velocity. References No footnotes date July 2009 http encyclopedia2.thefreedictionary.com Electron wake Encyclopedia article on the electron wake http ieeexplore.ieee.org iel5 4439904 4439905 04440675.pdf On the possibility of accelerating positron on an electron wake at saber See also Coulomb explosion Charged particle beam Linear particle accelerator Wake fields Wake fields Plasma acceleration Bremsstrahlung DEFAULTSORT Electron Wake Category Atomic physics Category Plasma physics Category Scattering physics stub ... more details
Wiktionarypar electron An electron is a subatomic particle. Electron may also refer to Electron bird , a genus of birds Electron vehicle , an electric urban vehicle concept by AMC Electron computer hacker , a member of an Australian hacking group Acorn Electron , an 8 bit computer by Acorn Computers Ltd Visa Electron , a brand of credit or debit cards Electron engine , a video game engine by Obsidian Entertainment L 188W Electron , an Argentine Navy version of the Lockheed L 188 Electra Electron comic book character , character by Apokalupsis Webcomics Electron or elementary charge e See also Elektron alloy , a range of magnesium alloys Electro disambiguation Elektron disambiguation Electrum disambig ast Electr n dixebra fr Electron nl Electron pl Electron uk ... more details
value and the reaction is called an Exothermic reaction exothermic process . Electroncapture ..., see Figure 3 in Marchywka Effect . See also Electroncapture mass spectrometry Koopmans theorem One ...File Electron Affinity in Band Diagram.png thumb Electron affinity E sub EA sub in a band diagram for solids .... The Electron affinity of an atom or molecule is defined as the amount of energy released when an electron is added to a neutral atom or molecule to form a negative ion. ref name Compendiumof GoldBookRef title Electron affinity file E01977 ref X e sup sup X sup sup This property is measured ... levels would be changed by contact with other atoms or molecules. A list of the electron affinities ... of the electron affinity and ionization potential . ref Robert S.Mulliken, Journal of Chemical Physics ... electron affinity include electronic chemical potential and chemical hardness . Another example, a molecule or atom that has a more positive value of electron affinity than another is often called an electron acceptor and the less positive an electron donor . Together they may undergo charge transfer reactions. In solids, the electron affinity is the energy difference between the vacuum energy ... L th, Springer, Berlin, 1999, 5.th edition ref To use electron affinities properly, it is essential ... sign implies a reversal of direction, and energy is required to attach an electron. In this case, the electroncapture is an endothermic process and the relationship, E sub ea sub E attach is still valid. Negative values typically arise for the capture of a second electron, but also for the nitrogen atom. br br The usual expression for calculating E sub ea sub when an electron is attached ..., electron affinity can also be defined as the amount of energy required to detach an electron ... Electron affinities of the elements Main Electron affinity data page Although E sub ea sub varies greatly ... electron. The electron affinities of the noble gases have not been conclusively measured, so ... more details
An electron avalanche is a process in which a number of free electron s in a Transmission medium medium usually a gas are subjected to strong acceleration by an electric field , ion izing the medium s atoms by collision called impact ionization , thereby forming new electrons to undergo the same process in successive cycles. This uncontrolled positive feedback loop leads to a type of chain reaction . Electron avalanches are essential to the dielectric breakdown process within gases. The process can culminate in corona discharge s, streamer s, leader spark leader s, or in a electric spark spark or continuous electric arc arc that completely bridges the gap. The process extends to huge sparks streamers in lightning discharges propagate by formation of electron avalanches created in the high potential gradient ahead of the streamers advancing tips. Once begun, avalanches are often intensified by the creation of photoelectron s as a result of ultraviolet radiation emitted by the excited medium s atoms in the aft tip region. The process can also be used to detect ionizing radiation that initiates the process, in as much as the passage of a single particles can amplified to large discharges. This is the mechanism of a Geiger counter and also the visualization possible with a spark chamber ... polarity, whereas the electron will be acceleration accelerated in the opposite direction. Because of the huge ... chain reaction or an electron avalanche additional electrons recently separated from their positive ... generated by just a single initial electron. However, free electrons are easily captured ... at a rate greater than they are being lost to capture, their number rapidly multiplies, a process ... free electron at position X sub 1 sub will result in M free electrons at position X sub 2 sub . Substituting ... gas molecule creating another accelerable electron. What differs is the source of this electron. When one or more electron avalanches occur between two electrodes of sufficient size, complete avalanche ... more details
Unreferenced stub auto yes date December 2009 Electron excitation is the movement of an electron to a higher energy state . This can either be done by photoexcitation PE , where the original electron absorbs the photon and gains all the photon s energy or by electrical Excited state excitation EE , where the original electron absorbs the energy of another, energetic electron. Within a semiconductor crystal lattice, thermal excitation is a process where lattice vibrations provide enough energy to move electrons to a higher energy band . When an excited electron falls back to a lower energy state again, it is called electron relaxation . This can be done by radiation of a photon or giving the energy to a third spectator particle as well. DEFAULTSORT Electron Excitation Category Electron Physics stub ja ... more details
Electron scattering is the process whereby an electron is deflected from its original trajectory . As they are charged particle s, they are subject to electromagnetic force s. Phenomena Electrons can be scattering scattered by other charged particles through the Coulomb s law electrostatic Coulomb forces . Furthermore, if a magnetic field is present, a traveling electron will be deflected by the Lorentz force . An extremely accurate description of all electron scattering, including quantum and relativistic aspects, is given by the theory of quantum electrodynamics . Types Common electron scattering processes include Compton scattering , in which an electron absorbs a photon and reemits it, changing the energy and momentum of both M ller scattering , in which two electrons scatter off of one another Bhabha scattering , in which an electron and a positron scatter Bremsstrahlung , in which an electron most commonly, but also any other particle passes by a heavy charged object like a nucleus , changes energy and direction, and emits a photon Deep inelastic scattering , in which a high energy electron interacts with a nucleus and breaks it up Synchrotron emission , in which an electron interacts with an external magnetic field, changes direction, and emits a photon. physics stub DEFAULTSORT Electron Scattering Category Electron Category Scattering de Elektronenstreuung it Scattering di elettroni ... more details
An electron donor is a chemical entity that donates electron s to another compound. It is a reducing agent that, by virtue of its donating electrons, is itself oxidize d in the process. Typical reducing agents undergo permanent chemical alteration through covalent or ionic reaction chemistry. This results in the complete and irreversible transfer of one or more electrons. In many chemical circumstances, however, the transfer of electronic charge to an electron acceptor may be only fractional, meaning an electron is not completely transferred, but results in an electron resonance between the donor ... retain their chemical identities. The electron donating power of a donor molecule is measured by its ionization potential which is the energy required to remove an electron from the highest occupied molecular orbital . The overall energy balance E , i.e., energy gained or lost, in an electron donor acceptor transfer is determined by the difference between the acceptor s electron affinity A and the ionization potential I math Delta E A I , math In chemistry , the class of electron donors that donate not just one, but a set of two paired electrons that form a covalent bond with an electron ... forces for electron donor and acceptor behavior in chemistry is based on the concepts of electropositivity for donors and electronegativity for acceptors of atomic or molecular entities. Electron donors in biology In biology , electron donors release an electron during cellular respiration , resulting in the release of energy . Microorganisms , such as bacteria , obtain energy in the electron ... use. The final result is the electron is donated to an electron acceptor. During this process electron transport chain the electron donor is oxidized and the electron acceptor is reduced. Petroleum hydrocarbons ... compounds are all compounds that can act as electron donors. These reactions are of interest not only ... electron donor.html Electron donor definition at United States Geological Survey Category Electrochemistry ... more details
An electron orbital may refer to An atomic orbital , describing the behaviour of an electron in an atom A molecular orbital , describing the behaviour of an electron in a molecule See also Electron configuration , the arrangement of electrons in structures such as atoms or molecules Orbital hybridization , a combining of atomic orbitals to form an equal number of hybrid orbitals when forming certain molecule s disambig vi Orbital ... more details
Electron optics deals with the focusing and deflection of electron s using magnetic field magnetic and or electrostatic field s. Electron properties main electron Electrons are charged particles point charge s with rest mass . The electron also has an associated spin physics spin of 1 2. While in motion an electron possesses kinetic energy , regardless of any imposed charge field this could be achieved ... imparts the energy required to accelerate the electron. Given sufficient voltage, the electron ..., phase and amplitude. With respect to electron optics, the nature of the electron as a charged particle causes electrons to interact with imposed electron fields, and their spin causes magnetic field interactions as well. These interactions form the fundamentals of electron optical theory. Field interactions Particle interpretation Magnetic fields interact with an electron in a manner that alters ... product of the magnetic field and the electron propagation vector, such that, in an infinite uniform field moving electrons take a circular motion at a constant radius dependent upon electron velocity ... from circular motion math r frac 2 m cv eH math where r is the orbit radius, m is the mass of an electron, v is the electron velocity, e is the charge on the electron and H is the applied magnetic ... period and the parallel velocity component. In the case of an applied electrostatic field, an electron ... exhibit non particle wave like effects such as diffraction , a full analysis of electron paths can ... the matter s electron charge cloud. Therefore electrons require vacuum to propagate any reasonable distance, such as would be desirable in electron optic systems. Penetration in vacuum is dictated ... values for which can be derived from Poisson statistics . See also Charged particle beam Electron beam technology Electron microscope Ernst Ruska References http www.ml.afrl.af.mil facilities mll cmc eo.html Air Force Research Laboratory Electron Optics Program DEFAULTSORT Electron Optics Category ... more details
Unreferenced stub auto yes date December 2009 Electron deficiency occurs when a compound has too few valence electron s for the connections between atoms to be described as covalent bond s. Electron deficient bonds are often better described as 3 center 2 electron bond s. Examples of compounds that are electron deficient are the borane s. The term electron deficient is also used in a more general way in organic chemistry , to indicate a pi bonding pi system such as an alkene or arene that has Polar effect electron withdrawing groups attached, as found in nitrobenzene or acrylonitrile . Instead of showing the nucleated character common with simple C C bonds, electron deficient pi systems may be electrophile electrophilic and susceptible to nucleophilic attack, as is seen in the Michael addition or in nucleophilic aromatic substitution . As the most extreme form of highly localize electron deficiency one can consider the metallic bond . DEFAULTSORT Electron Deficiency Category Chemical bonding Chem stub ar de Elektronenmangelbindung nl Elektronendefici ntie pt Defici ncia de el trons zh ... more details
An electron acceptor is a chemical entity that accepts electron s transferred to it from another compound. It is an oxidizing agent that, by virtue of its accepting electrons, is itself redox reduced in the process. ref http toxics.usgs.gov definitions electron acceptor.html ref Typical oxidizing agents undergo permanent chemical alteration through covalent or ionic reaction chemistry, resulting in the complete and irreversible transfer of one or more electrons. In many chemical circumstances, however, the transfer of electronic charge from an electron donor may be only fractional, meaning an electron is not completely transferred, but results in an electron resonance between the donor and acceptor ... their chemical identities. The electron accepting power of an acceptor molecule is measured by its electron affinity which is the energy released when filling the lowest unoccupied molecular orbital LUMO . The overall energy balance E , i.e., energy gained or lost, in an electron donor acceptor transfer is determined by the difference between the acceptor s electron affinity A and the ionization potential I of the electron donor math Delta E A I , math . In chemistry , a class of electron acceptors that acquire not just one, but a set of two paired electrons that form a covalent bond with an electron ... The driving forces for electron donor and acceptor behavior in chemistry is based on the concepts .... Examples Examples of electron acceptors include oxygen , nitrate , iron III , manganese IV , sulfate .... Fact date March 2008 In biology , a terminal electron acceptor is a compound that receives or accepts an electron during cellular respiration or photosynthesis . All organisms obtain energy by transferring electrons from an electron donor to an electron acceptor. During this process electron transport chain the electron acceptor is reduced and the electron donor is oxidized . See also redox ... definitions electron acceptor.html Electron acceptor definition at United States Geological ... more details
Electron Equivalent is a concept commonly used in redox chemistry , reactions involving electron transfer , to define a quantity e.g. energy or moles relative to one electron. Gibbs free energy Energies of formation are often given as kilojoules per electron equivalent to enable calculation of specific reaction energies on a per electron basis. Reactions containing movement of electrons are often balanced such that reaction quantities are given in relation to the transfer of a single electron, allowing quantification of reactants and products in relation to a single electron transfer. References Refbegin cite book last1 Rittman first1 B.E. last2 McCarty first2 P.L. title Environmental Biotechnology Principles and Applications publisher McGraw Hill date 2001 page 60 isbn 0072345535 cite book last1 Schwarzenbach first1 Rene P. last2 Gschwend first2 Philip M. last3 Imboden first3 Dieter title Environmental Organic Chemistry edition 2nd date 2003 isbn 0471357302 publisher John Wiley & Sons page 568 cite book last1 Sayyar first1 Bahareh title Thermodynamic electron equivalent models for Geobacter species publisher University of Toronto Canada date 2008 isbn 0494449144 Refend Category Thermodynamic free energy Category Fundamental physics concepts Category Chemical reactions chemistry stub ... more details
DISPLAYTITLE Electron bird Taxobox name Electron image Electron platyrhynchum Panama 8a.jpg image width 250px image caption Broad billed Motmot regnum Animal ia phylum chordate Chordata classis Aves ordo Coraciiformes familia Motmot idae genus Electron genus authority Johannes Gistel Gistel , 1848 subdivision ranks Species subdivision Keel billed Motmot E. carinatum br Broad billed Motmot E. platyrhynchum Electron is a genus of the motmot s, a family biology family of Neotropics Neotropical near passerine bird s. The genus has two species Keel billed Motmot , Electron carinatum Broad billed Motmot , Electron platyrhynchum Both inhabit humid evergreen tropical forest. Both occur in Central America , and the Broad billed Motmot occurs in a large region of South America as well. They are distinguished from other motmots by their much wider bills. The rackets on their tails are less dramatic than those of many other motmot species and may be absent. The species are very similar except in adult plumage but the adult Keel billed resembles the juvenile Broad billed . A mixed pair apparently courting has been observed Howell and Webb 1995 . The name Electron is a Latin ization of the Ancient Greek word for amber , and can mean bright in scientific names Jaeger 1978 the amber colored eyes of the Keel billed Motmot Howell and Webb 1995 may be the connection. Citation needed date August 2007 The name was given 46 years before an elementary particle was named electron . References Cite book last Howell first Steve N. G. coauthors Webb, Sophie title A Guide to the Birds of Mexico and Northern Central America publisher Oxford University Press pages 439, 790 791 year 1995 isbn 0 19 854012 4 Cite book last Jaeger first Edmund C. authorlink Edmund Jaeger title A Source Book of Biological ... . Accessed 2007 08 17. DEFAULTSORT Electron Bird Category Momotidae Coraciiformes stub ca Electron es Electron ave fr Electron oiseau hu Electron nl Electron geslacht pl Electron ptaki ... more details
Interventions infobox Name PAGENAME Image Caption ICD10 ICD9unlinked ICD9proc 92.25 MeshID OPS301 OtherCodes Electron therapy or Electron Beam Therapy EBT is a kind of external beam radiotherapy where electrons are directed to a tumor site. Equipment Electron beam therapy is performed using a medical linear accelerator . This device can also be used to produce high energy photon beams. When electrons are required, the x ray target is retracted out of the beam and the electron beam is collimated with a piece of apparatus known as an applicator or an additional collimating insert, constructed from a low melting point alloy. Properties Electron beams have a finite range, after which the dose falls off rapidly. Therefore they spare deeper healthy tissue. The depth of the treatment is selected by the appropriate energy. Indications Electron beam therapy is used in the treatment of superficial tumors like cancer of skin regions, or total skin e.g. mycosis fungoides , diseases of the limbs e.g. melanoma and lymphoma , nodal irradiation, and it may also be used to boost the radiation dose to the surgical bed after mastectomy or lumpectomy . For deeper regions IOERT Intraoperative electron radiation therapy might be applied. References Eric E. Klein Electron Beam Therapy Dosimetry, Planning, and Techniques in Edward C. Halperin, Carlos A. Perez, Luther W. Brady ed. Perez and Brady s Principles and Practice of Radiation Oncology, 5th. edition, 2008 See also Intraoperative Electron Radiation Therapy IOERT IOERT External beam radiotherapy EBRT EBRT Radiation oncology DEFAULTSORT Electron Therapy Category Electron beams in medical applications Category Medical physics Category Radiation oncology ar ... more details
Unreferenced date January 2008 File Egun.jpg thumb 250px right Electron gun from a cathode ray tube File Kathodestraalbuis2.jpg thumb 250px right Electron gun from an oscilloscope CRT An electron gun also called electron emitter is an electrical component that produces an electron beam that has a precise kinetic energy and is most often used in television set s and computer display s which use cathode ray tube CRT technology, as well as in other instruments, such as electron microscope s and particle accelerators . Electron guns may be classified in several ways by the type of electric field generation DC or RF , by emission mechanism thermionic emission thermionic , photocathode , field electron emission cold emission , Plasma physics plasmas source , by focusing pure electrostatic or with magnetic fields , or by the number of electrodes. Characteristics A direct current, electrostatic thermionic electron gun is formed from several parts a hot cathode , which is heated to create a stream of electrons via thermionic emission , electrodes generating an electric field which focus the beam ... where gas enters from one end face, undergoes electron bombardment from the side walls, and is subjected ... color cathode ray tubes such as those used in color television s incorporate three electron guns, each ... primary color s. Applications The most common use of electron guns is in cathode ray tube cathode ray tubes , which were widely used in computer and television monitors. An electron gun can also ... used in mass spectrometry in a process called electron ionization to ionize vaporized or gaseous particles. See also Cathode ray tube Electron microscope Optics Particle accelerators References references External links http electronics.howstuffworks.com question694.htm Howstuffworks.com electron gun http www.fieldp.com cpb.html Charged Particle Beams , free text with material on electron gun design Category Electron beam Category Particle accelerators Category Vacuum tubes de Elektronenkanone ... more details
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