演示文稿专业英语

Gas,LiquidandSolidhightemperatureslowtemperaturesKineticEnergyAttractiveIntermolecularForces气体，液体和固体[disˈɔ:də]混乱[ˈpɑ:tikl]微粒[kəmˈpres]压缩[ˈklʌstə]聚集[ˈkrɪstəlaɪn]结晶IonicForces++----+++Ion-Ione.g.NaCl(s)Ion-DipoleIonsformstrongforceswithmoleculewater.Ion-ionforcesareverystrongandproducehighboilingpointsandmeltingpoints.e.g.NaCldissolvedinwaterIonicLiquids离子间作用力离子-离子离子-偶极分子[ˈaɪən][ˈdaipəul]intermolecular[intə(:)məˈlekjulə]polar[ˈpəulə](Threeimportantintermolecularinteractions)•Forces(non-polarmolecules)•Forces(polarmolecules)Forces(moleculeswithF-H,O-H,N-Hbonds).[ˌɪntərˈækʃən]相互作用[disˈpə:ʃən][ˈdaipəul]偶极[ˈhaidrədʒən][ˈbɔndiŋ]分散力氢键IntermolecularInteractionsDispersionDipole-DipoleHydrogenBondingDispersionForcesTheononeatomareattractedtotheonaneighbouringatom.Thiscreatesan“”(i.e.（=idest）temporary)dipoleonthefirstatom.Theinstantaneousdipoleonthefirstatomtheninducesaninstantaneousdipoleonthesecondatom.Thetwoinduceddipolesattracteachother.[ˈhi:li:əm]氦[ˈvændə:ˌwɔ:lz]范德华力[iˈlektrɔn]电子[ˈnju:kliəs]核[ˌɪnstənˈteinjəs]瞬时(vanderWaalsForces)electronsnucleusinstantaneousDispersionForces(vanderWaalsForces)•DispersionForcesaretoamolecule’s•Thepolarizability,theeasewithwhichthee-cloudcanbe,isapproximatelyproportionaltothenumberofelectronsandweight.[ˈpəuləˌraizəˈbiləti]极化率，极化度[prəˈpɔ:ʃənəl]成比例的[dɪˈfɔ:m]使变形[məˈlekjələ]分子的proportionalpolarizabilitydeformedmolecularForexample,theconsistof,non-polaratoms……ElementMolecularweightNumberofe-Boilingpoint/KHelium4.024氖20.21027氩39.91887氪83.936121氙131.354166•Asthemolecule(atom)increasesinsize,theboilingpointincreases,sodoesthepolarizability,thereforedispersionforcesincrease.•DispersionForcesalsodependuponthemolecularshape.惰性气体[ˈsfɪərɪkəl]球形的NeonArgon[ˈɑ:ɡɔn]Krypton[ˈkriptɔn]Xeon[ˈzenɔn]sphericalnoblegases[ni:ən]Dipole-DipoleForcesInliquidsofpolarmolecules,oppositelyendsofthemoleculestendtoattracteachother,causingpartial.FormoleculesofroughlyequalMW’s(i.e.withsimilarDispersionForces),themoleculewiththehigherwillhaveahigherboilingpointduetogreaterDipole-Dipoleforces.CCCHHHHHHHHPropane,MW=44Acetonitrile,MW=41CCHHHN0NoDipoleMoment,Tbp=-42oC=3.9Debye(D)LargeDipoleMoment,Tbp=+82oC[tʃɑ:dʒd]带电荷[əˈlaɪnmənt]排成直线偶极距chargedalignmentdipolemomentHydrogenBonding•HydrogenbondisaspecialintermolecularinteractionbetweentheHatominapolarN-H,O-HorF-HbondandanO,NorFatom.[iˌlektrəuˈneɡətiv]带负电荷[kəuˈveilənt]共价键electronegativePropertiesofLiquidsViscosity•Viscosityistheresistanceofaliquidtoflowing.•Highviscosityliquids(e.g.,)flowslowly.Lowviscosityliquids(e.g.water,)flowquickly.•Whenaliquidflowsdownatube,themoleculesslideoveroneanother.Thehighertheforcesofattraction,thelessofatendencytheliquidwillhavetoflow,andthehigherwillbetheviscosity.黏度[məˈlæsɪz]糖浆,机油汽油molassesmotoroilgasolineSurfaceTensionAmoleculeintheliquidisstabilizedbytheattractionoftheotherliquidmolecules.Amoleculeonthesurfacewillbeatahigherenergythanoneinthebulkoftheliquid.Surfacetensionisameasureofthestrengthofintermolecularattractionswhichpullonmoleculesatthesurfaceofaliquid.[bʌlk]大量表面张力bulkSurfaceTension•Thestrongerintermolecularforces,thehighersurfacetension.•SurfacetensionisresponsiblefortheriseofaliquidsuchasH2Oinathinglass.ThisalsogivesrisetoawhenwateroranaqueoussolutionisinaoraAdhesionCohesionAdhesionCohesionisanattractionbetweenunlikemoleculesistheattractionbetweenlike-molecules[ˈkæpəˌleri:]毛细管[miˈniskəs]新月面[piˈpet]吸液管[bjuəˈret]滴管[ædˈhi:ʒən]粘附力[kəʊˈhi:ʒən]内聚力capillarymeniscuspipetteburetteAdhesionCohesionSurfaceTensionItisbecauseofitshighsurfacetensionthatwatertendsto“”uponasurface.That’sbecauseagivestheminimumratioofsurfaceareatovolume.Thehighsurfacetensionofwateralsocausesmoleculesonthesurfacetopackverycloselytogether.Thisiswhysomeinsectscan“walkonwater”.[bi:d]形成小水珠[ˈwæksi]光滑的[sfiə]球体表面积对体积的比例最小beadwaxysphereStructureofSolids•Acrystallinesolidpossessesrigidandlong-rangeorder.Inacrystallinesolid,atoms,moleculesorionsoccupyspecific()positions•Ansoliddoesnotpossessawell-definedarrangementandlong-rangemolecularorder.Irregular(disordered)arrangementofatoms(ormolecules)arefoundinanamorphoussolid.Crystallinesolid,e.g.Quartz(SiO2)Amorphoussolide.g.SilicaGlass(SiO2)长程有序[əˈmɔ:fəs]无定形的固定的predictableamorphousThankyou!TheCrystallineLattice•Latticeisthethreedimensionalarrayofpointsrepeatingperiodically.•Latticepointcanbeatoms,moleculesandions.•Unitcellisthebasicrepeatingstructuralunitofacrystallinesolid.unitcelllatticepoint3-Dlatticearrangement晶格点晶胞单元UnitcellTheunitcellsstackedin3-Dspacedescribethebulkarrangementofatomsofthecrystal.Theunitcellisgivenbyitslatticeparameters：thelengthofthecelledges&theanglesbetweenthem.whilethepositionsoftheatomsinsideaunitcellaredescribedbythesetofatomicpositionsmeasuredfromalatticepoint.原子集合体从晶格的一个角度TypesofSolids•Therearefourclassificationsofsolids,dependingonthetypeofbondsthatarepresent:IonicSolids,MetallicSolids,MolecularSolidsandCovalentNetworkSolids.IonicSolids•Latticepointsoccupiedbyandheldtogetherbyattraction.•Hard,,highmeltingpoint,poorconductorofheatandelectricity•Examples:Alltypicalsalts,e.g.NaC