原子结构备课参考资源09.ppt

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1、Chapter2.AtomicStructure(原子結構)HistoricalDevelopmentofAtomicTheoryIn1808.JohnDalton:AtomictheoryAllmatteriscomposedofsmallparticlescalledatoms.Anatom(原子):indivisible,retainitsidentityduringchemicalreactionsAnelement(元素):Atypeofmatterofonlyonekindofatom,e.g.hydrogen(H),oxygen(O)Daltondidnotknowther

2、eweresub-atomicparticlesintheatoms.electronsB.neutronsC.protonsIn1869DmitriMendeleev(Russian)J.LotharMeyer(German)PeriodicTableofElements(元素週期表)Chapter2AtomicStructureBasicQuantumMechanics(量子力學)SubatomicParticlesTheElectronJ.J.Thomsoncreditedwiththediscoveryin1897Previously,atomswerebelievedtobe

3、thesmallestparticlesWilliamMorgan(1785)—passedcurrentthroughavacuumProducedaglowLuigiGalvani(1800)—firstproducedconstantcurrentfromabatteryCu(wetsaltsolution)SnEcell=+0.48VMichaelFaraday(1836)—determinesglowcomesfromthecathodeEugeneGoldstein(1876)—coinstheterm“cathoderay”Thomsonfindselectronisneg

4、ativelychargedwith1/1836massofHThomson’sExperimentRepulsionfromnegativepoleofanelectricfieldmeantthatthecathoderaysmustbenegativelychargedTheamountofdeflectionwasafunctionofthemassofthe“ray”Sincemanydifferentmetalsallproducedthesame“cathoderays,”allatomsmustbemadeupofthesame+/-particlesG.F.FitzGe

5、raldrenamescathoderaysasElectronsTheNucleusErnestRutherfordcreditedwithdiscoveringtheNucleusin1911Henuclei(aparticle)weredeflectedastheypassedthroughaGoldfoilConclusion:Heavy,tinynucleusandmuchemptyspaceinanatomTheProtonRutherfordandMoseleyquicklydiscoveredthechargeofthenucleusbyX-rayemissionin19

6、13Z=thenuclearcharge(ortheatomicnumber)AtomicSpectraBalmerdescribedtheemissionspectrumofHin1885..n=principlequantumnumber=discreteallowedenergiesforHelectronsnh=integer>2RH=Rydbergconstant=1.097x107m-1h=Planck’sconstant=6.626x10-34Js=frequencyoflights-1c=speedoflight=2.998x108m/s=wavelengthnm=wav

7、enumbercm-1Bohr’sQuantumTheoryoftheAtom(1913)Negativeelectronsmoveinstable,circularorbitsaroundpositivenucleiElectronsabsorboremitlightbymovingoutormovingintootherorbitsBohrreplacedBalmer’sequationswithbetteronesEnergy