Periodiske system Wikipedia, den frie encyklopdi. Det moderne periodiske system, i 1. Det periodiske system er en tabelarrangering af grundstofferne, ordnet efter deres atomnumre antal protoner, elektronkonfigurationer og gennemgende kemiske egenskaber. Relativistic Quantum Mechanics By Bjorken And Drell Pdf' title='Relativistic Quantum Mechanics By Bjorken And Drell Pdf' />In theoretical physics, quantum chromodynamics QCD is the theory of the strong interaction between quarks and gluons, the fundamental particles that make up. Information for Authors and Subscribers Progress in Physics has been created for publications on advanced studies in theoretical and experimental physics, including. La tavola periodica degli elementi o semplicemente tavola periodica lo schema con cui sono ordinati gli elementi chimici sulla base del loro numero atomico Z e. Denne ordning viser periodiske tendenser, ssom elementer med lignende opfrsel i samme sjle. Det viser ogs fire rektangulre blokke med omtrentligt ens kemiske egenskaber. Generelt glder det indenfor enhver rkke, at metallerne er i venstre side og ikkemetallerne er i hjre side. Rkkerne i systemet kaldes perioder sjlerne kaldes grupper. Seks grupper har navne svel som numre for eksempel kaldes gruppe 1. Det periodiske system er en tabelarrangering af grundstofferne, ordnet efter deres atomnumre antal protoner, elektronkonfigurationer og gennemgende kemiske egenskaber. Tunneling Effect Quantum tunnelling. Det periodiske system kan bruges til at udlede forholdene mellem grundstoffernes egenskaber og forudsige egenskaberne for nye grundstoffer, der endnu ikke er blevet opdaget eller syntetiseret. Det periodiske system er et nyttigt framework til analyse af kemisk opfrsel og bruges bredt indenfor kemi og andre videnskaber. Dmitrij Mendelejev udgav i 1. Han udviklede sit system for at illustrere de periodiske tendenser i egenskaberne blandt de dengang kendte grundstoffer. Mendelejev forudsagde ogs nogle egenskaber for dengang ukendte grundstoffer, som han forventede ville udfylde nogle huller i hans system. De fleste af hans forudsigelser blev bevist at vre korrekte, da de pgldende grundstoffer efterflgende blev opdaget. F978-3-642-88082-7_1/lookinside/000.png' alt='Relativistic Quantum Mechanics By Bjorken And Drell Pdf' title='Relativistic Quantum Mechanics By Bjorken And Drell Pdf' />Mendelejevs periodiske system er sidenhen blevet udvidet og forfinet i takt med opdagelsen eller syntetiseringen af flere nye grundstoffer og udviklingen af nye teoretiske modeller til at forklare kemisk opfrsel. Alle grundstofferne fra atomnummer 1 hydrogen til 1. De seneste tilfjelser grundstof 1. IUPAC 3. 0. december 2. De frste 9. 4 grundstoffer eksisterer naturligt, selvom nogle kun findes i spormngder og blev syntetiseret i laboratorier, fr de blev fundet i naturen. Grundstofferne med atomnumrene 9. Flere syntetiske radionuklider af naturligt forekommende grundstoffer er ogs blevet produceret i laboratorier. Der forsges aktivt at syntetisere grundstoffer med hjere atomnumre. Hvert grundstof har et unikt atomnummer Z, der reprsenterer antallet af protoner i dets kerne. De fleste grundstoffer har forskellige antal neutroner blandt de forskellige atomer. Disse varianter kaldes isotoper. For eksempel har carbon tre naturligt forekommende isotoper alle dets atomer har seks protoner, og de fleste har ogs seks neutroner, men omkring 1 har syv neutroner, og en meget lille andel har otte neutroner. Isotoper separeres aldrig i det periodiske system de grupperes altid sammen under et enkelt grundstof. Grundstoffer uden stabile isotoper har deres mindst ustabile isotopers atommasser vist i parentes. I standardudgaven af det periodiske system opfres grundstofferne efter stigende atomnummer antallet af protoner i et atoms kerne. En ny rkke kaldet en periode pbegyndes nr en ny elektronskal fr sin frste elektron. Sjler grupper afgres af atomets elektronkonfiguration grundstoffer med det samme antal elektroner i en bestemt underskal placeres i den samme gruppe oxygen og selenium er eksempelvis i samme gruppe fordi de begge har fire elektroner i den yderste p underskal. Grundstoffer med lignende kemiske egenskaber placeres generelt i den samme gruppe i det periodiske system, selvom grundstofferne i f blokken, og til en vis grad i d blokken, ofte ogs deler egenskaber med andre grundstoffer i samme periode. Det er derfor relativt let at forudsige et grundstofs kemiske egenskaber hvis man kender egenskaberne for de grundstoffer, der omgiver det. Pr. Grundstofferne 1. International Union of Pure and Applied Chemistry IUPAC i december 2. Adobe Acrobat 8.0 Activation Code'>Adobe Acrobat 8.0 Activation Code. Deres foreslede navne, hhv. Nh, moscovium Mc, tennessine Ts og oganesson Og, blev bekendtgjort af IUPAC i juni 2. Disse navne vil ikke blive formelt godkendt fr efter den fem mneder lange periode for offentlige kommentarer slutter i november 2. Indtil da identificeres de formel ved deres atomnummer f. Uut. 8fremtidigt infoDe frste 9. Af de 9. 4 naturligt forekommende grundstoffer er 8. En gruppe eller familie er en lodret sjle i det periodiske system. Grupper har normalt mere signifikante periodiske tendenser end perioder og blokke. Moderne kvantemekaniske teorier om atomstruktur forklarer gruppetendenser ved at foresl, at grundstoffer indenfor samme gruppe generelt har de samme elektronkonfigurationer i deres valensskal. Som konsekvens heraf har grundstofferne i samme gruppe en tendens til at have en del kemi til flles, og udviser klare tendenser i egenskaber med stigende atomnummer. I nogle dele af det periodiske system, ssom d blokken og f blokken, kan de vandrette ligheder dog vre lige s vigtige, hvis ikke vigtigere, end de lodrette ligheder. Som flge af en international navngivningskonvention er grupperne nummereret fra 1 til 1. De var tidligere nummereret i romertal. I USA blev romertallene fulgt af enten et A, hvis gruppen var i s blokken eller p blokken, eller et B hvis gruppen var i d blokken. Romertallene svarede til det sidste tal i den moderne navngivningskonvention dvs. IVB, og gruppe 1. IVA. I Europa var bogstaverne lignende, bortset fra at A blev brugt hvis gruppen var fr gruppe 1. B blev brugt for grupper fra og med gruppe 1. Herudover blev gruppe 8, 9 og 1. VIII. I 1. 98. 8 blev det nye IUPAC navngivningssystem taget i anvendelse, og de gamle gruppenavne blev betragtet som forldede. Nogle af disse grupper har fet trivialnavne, selvom nogle af disse sjldent anvendes. Gruppe 31. 0 har ingen trivialnavne, og omtales kun ved deres gruppenummer eller ved navnet p det frste grundstof i gruppen ssom scandiumgruppen for gruppe 3, da de udviser frre ligheder ogeller lodrette tendenser. Grundstoffer i den samme gruppe har en tendens til at udvise mnstre i atomradius, ioniseringsenergi og elektronegativitet. Grundstoffernes atomradius ges fra toppen af gruppen og til bunden. Da der er flere fyldte energiniveauer, findes valenselektroner lngere fra kernen. Fra toppen og ned har hvert p hinanden flgende grundstof en lavere ioniseringsenergi, da det er lettere at fjerne en elektron idet atomerne er mindre stramt bundet. P samme mde har en gruppe fra toppen og ned en aftagende elektronegativitet p grund af en get afstand mellem valenselektroner og kernen. Der er dog undtagelser fra disse tendenser et eksempel p dette er i gruppe 1. Gruppenr. nb 11. MendelejevIVIIIIAIIAIIIBIVBVBVIBVIIBVIIIBIBIIBIIIBIVBVBVIBVIIBnb 3CASUSA, A B AIAIIAIIIBIVBVBVIBVIIBVIIIBIBIIBIIIAIVAVAVIAVIIAVIIIAgl. IUPACEuropa, A BIAIIAIIIAIVAVAVIAVIIAVIIIBIBIIBIIIBIVBVBVIBVIIB0. Trivialnavn. Alkalimetaller. Jordalkalimetaller. Chalkogener. Halogenerdelgasser. Navn efter grundstof. Lithiumgr. Berylliumgr. Scandiumgr. Titaniumgr. Vanadiumgr. Kromgr. Mangangr. Jerngr. Koboltgr. Nikkelgr. Kobbergr. Zinkgr. Borgr. Kulstofgr. Kvlstofgr. Iltgr. Fluorgr. Helium eller Neongr. Periode 1. Hnb 4He. Periode 2. Li. Be. BCNOFNe. Periode 3. Na. Mg. Al. Si. PSCl. Ar. Periode 4. KCa. Sc. Ti. VCr. Mn. Fe. Co. Ni. Cu. Zn. Ga. Ge. As. Se. Br. Kr. Periode 5. Rb. Srnb 2YZr. Nb. Mo. Tc. Ru. Rh. Pd. Ag. Cd. In. Sn. Sb. Te. IXe. Periode 6. Cs. Ba. LaYb. Lunb 2Hf. Ta. WRe. Os. Ir. Pt. Au. Hg. Tl. Pb. Bi. Po. At. Rn. Periode 7. Fr. Ra. AcNo. Lrnb 2Rf. Db. Sg. Bh. Hs. Mt. Ds. Rg. Cn. Nh. Fl. Mc. Lv. Ts. OgNuvrende, moderne IUPAC gruppenummer. Quantum chromodynamics Wikipedia. In theoretical physics, quantum chromodynamics QCD is the theory of the strong interaction between quarks and gluons, the fundamental particles that make up composite hadrons such as the proton, neutron and pion. QCD is a type of quantum field theory called a non abelian gauge theory, with symmetry group SU3. The QCD analog of electric charge is a property called color. Gluons are the force carrier of the theory, like photons are for the electromagnetic force in quantum electrodynamics. The theory is an important part of the Standard Model of particle physics. A large body of experimental evidence for QCD has been gathered over the years. QCD exhibits two main properties Color confinement, the phenomenon that color charged particles such as quarks and gluons cannot be isolated and exist only within hadrons or high temperature plasmas. This is a consequence of the constant force between two color charges as they are separated In order to increase the separation between two quarks within a hadron, ever increasing amounts of energy are required. Eventually this energy produces a quarkantiquark pair, turning the initial hadron into a pair of hadrons instead of producing an isolated color charge. Although analytically unproven, color confinement is well established from lattice QCD calculations and decades of experiments. TerminologyeditAmerican physicist Murray Gell Mann b. It originally comes from the phrase Three quarks for Muster Mark in Finnegans Wake by James Joyce. On June 2. 7, 1. 97. Gell Mann wrote a private letter to the editor of the Oxford English Dictionary, in which he related that he had been influenced by Joyces words The allusion to three quarks seemed perfect. Originally, only three quarks had been discovered. Gell Mann, however, wanted to pronounce the word to rhyme with fork rather than with park, as Joyce seemed to indicate by rhyming words in the vicinity such as Mark. Gell Mann got around that by supposing that one ingredient of the line Three quarks for Muster Mark was a cry of Three quarts for Mister. H. C. Earwickers pub, a plausible suggestion given the complex punning in Joyces novel. The three kinds of charge in QCD as opposed to one in quantum electrodynamics or QED are usually referred to as color charge by loose analogy to the three kinds of color red, green and blue perceived by humans. Other than this nomenclature, the quantum parameter color is completely unrelated to the everyday, familiar phenomenon of color. The force between quarks is known as the colour force6 or color force7 or strong interaction, and is responsible for the strong nuclear force. Since the theory of electric charge is dubbed electrodynamics, the Greek word chroma color is applied to the theory of color charge, chromodynamics. HistoryeditWith the invention of bubble chambers and spark chambers in the 1. It seemed that such a large number of particles could not all be fundamental. First, the particles were classified by charge and isospin by Eugene Wigner and Werner Heisenberg then, in 1. Murray Gell Mann and Kazuhiko Nishijima see Gell MannNishijima formula. To gain greater insight, the hadrons were sorted into groups having similar properties and masses using the eightfold way, invented in 1. Free Sample Employment Contract Agreement Forms. Gell Mann1. 1 and Yuval Neeman. Gell Mann and George Zweig, correcting an earlier approach of Shoichi Sakata, went on to propose in 1. Perhaps the first remark that quarks should possess an additional quantum number was made1. Boris Struminsky1. Pauli exclusion principle Three identical quarks cannot form an antisymmetric S state. In order to realize an antisymmetric orbital S state, it is necessary for the quark to have an additional quantum number. B. V. Struminsky, Magnetic moments of barions in the quark model, JINR Preprint P 1. Dubna, Submitted on January 7, 1. Boris Struminsky was a Ph. D student of Nikolay Bogolyubov. The problem considered in this preprint was suggested by Nikolay Bogolyubov, who advised Boris Struminsky in this research. In the beginning of 1. Nikolay Bogolyubov, Boris Struminsky and Albert Tavkhelidze wrote a preprint with a more detailed discussion of the additional quark quantum degree of freedom. This work was also presented by Albert Tavchelidze without obtaining consent of his collaborators for doing so at an international conference in Trieste Italy, in May 1. A similar mysterious situation was with the baryon in the quark model, it is composed of three up quarks with parallel spins. In 1. 96. 46. 5, and Greenberg1. HanNambu1. 8 independently resolved the problem by proposing that quarks possess an additional SU3gaugedegree of freedom, later called color charge. Han and Nambu noted that quarks might interact via an octet of vector gauge bosons the gluons. Since free quark searches consistently failed to turn up any evidence for the new particles, and because an elementary particle back then was defined as a particle which could be separated and isolated, Gell Mann often said that quarks were merely convenient mathematical constructs, not real particles. The meaning of this statement was usually clear in context He meant quarks are confined, but he also was implying that the strong interactions could probably not be fully described by quantum field theory. Richard Feynman argued that high energy experiments showed quarks are real particles he called them partons since they were parts of hadrons. By particles, Feynman meant objects which travel along paths, elementary particles in a field theory. The difference between Feynmans and Gell Manns approaches reflected a deep split in the theoretical physics community. Feynman thought the quarks have a distribution of position or momentum, like any other particle, and he correctly believed that the diffusion of parton momentum explained diffractive scattering. Although Gell Mann believed that certain quark charges could be localized, he was open to the possibility that the quarks themselves could not be localized because space and time break down. This was the more radical approach of S matrix theory. James Bjorken proposed that pointlike partons would imply certain relations should hold in deep inelastic scattering of electrons and protons, which were verified in experiments at SLAC in 1. This led physicists to abandon the S matrix approach for the strong interactions. In 1. 97. 3 the concept of color as the source of a strong field was developed into the theory of QCD by European physicists Harald Fritzsch and Heinrich Leutwyler, together with American physicist Murray Gell Mann. In particular, they employed the general field theory developed in 1. Chen Ning Yang and Robert Mills2. YangMills theory, in which the carrier particles of a force can themselves radiate further carrier particles. This is different from QED, where the photons that carry the electromagnetic force do not radiate further photons. The discovery of asymptotic freedom in the strong interactions by David Gross, David Politzer and Frank Wilczek allowed physicists to make precise predictions of the results of many high energy experiments using the quantum field theory technique of perturbation theory. Evidence of gluons was discovered in three jet events at PETRA in 1.