资源描述
Anythingthathasmassandvolume(takesupspace)Pure SubstanceAtypeofmatterwithafixedcomposition.Allofparticlesthatmakeupthissubstancearealike.Element A substance that cannot be broken down into simpler substances by ordinary means(heating or any chemical process).90 naturally occurring elements.Arranged in an order on Periodic TableThe Greek Model1.DemocritusGreekphilosopherwhotheorizedaboutwhethermattercouldbedividedintosmallerandsmallerpieces.A.Concludedthatmattercouldnotbedividedintosmallerandsmallerpiecesforever.B.NamedthesmallestpiecesofmatterAtom.The Greek ModelDemocritus2.HypothesizedAtomswereinfiniteinnumber,alwaysmoving,andcapableofjoiningtogether.3.NotwidelyacceptedCouldnotprovetheories.AtomThesmallestparticleofanelementthathasthepropertiesofthatelement.BasicbuildingblocksofmatterJohnDaltonEnglishchemistBasicIdeasofDaltonsAtomicTheory:A.AllelementsarecomposedofatomsAtomsareindivisibleandindestructibleparticles.SimilartoDemocritusB.Atomsofthesameelementareexactlyalike.BasicIdeasofDaltonsAtomicTheory(cont):C.Atomsofdifferentelementsaredifferent.D.Compoundsareformedbythejoiningofatomsof2ormoreelements.FoundationofmodernchemistryJ.J.ThomsonEnglishchemist1.BasicIdeaofThomsonsModelA.Atomsaremadeofevensmallerparticles.B.StudiedthepassageofanelectriccurrentthroughagasGasgaveoffraysthatweremadeofnegativelychargedparticles-CorpusclesTodayElectrons2.AtomsthoughttohaveaneutralchargeFindingelectronschangedidea.A.Thomsonunabletoshowparticlesthathadapositivecharge.3.ProposedamodelofanatomPlum PuddingTheatomwasmadeofapudding-likepositivelychargedmaterialthroughoutwhichnegativelychargedelectronswerescattered,likeplumsinapudding.WhatarethesignificantdifferencesbetweenDaltonsmodelandThomsonsmodeloftheatom?AtomwasnotasingleparticleItwasmadeofpositiveandnegativeparticlesErnestRutherfordEnglishphysicist.1.RutherfordsExperimentA.Firingastreamoftinypositivelychargedparticlesatthinsheetofgoldfoil.1.RutherfordsExperimentB.Mostofthepositivelycharged“bullets”passedthroughthegoldatomsinthesheetoffoil.C.Some“bullets”didbounceawayfromthegoldsheetsasiftheyhadhitsomethingsolidSomebouncedstraightback.Conclusion:Atommusthaveasmall,dense,positivelychargedcenterNucleus2.RutherfordsTheoryTwopartsofanatom:A.Allofanatomspositivelychargedparticleswerecontainedinthenucleus.B.Thenegativelychargedelectronswerescatteredoutsidethenucleusaroundtheatomsedge.2.RutherfordsTheoryC.Betweenthenucleusandtheelectronswasmostlyemptyspace.D.Negativelychargedelectronswereheldinanatombytheattractionbetweenthemandthepositivelychargednucleus.WhatarethesignificantdifferencesbetweenThomsonsmodelandRutherfordsmodeloftheatom?Themassoftheatomisatthecenteroftheatominsteadofthroughouttheatomelectronsorbitthenucleus.NielsBohrDanishscientist.1.Proposedthelocationofelectrons.B.Theorbits,orenergylevels,arelocatedatcertaindistancesfromthenucleus.4.WorkedinexplainingthestructureandbehaviorofsimpleatomsNotcomplexatoms2.BohrsTheoryA.Electronsmoveindefiniteorbitsaroundthenucleus.WhatarethesignificantdifferencesbetweenRutherfordsmodelandtheBohrmodeloftheatom?The orbits of the electrons are not random but are fixed distances from the nucleus.Protons and neutrons are in the nucleusModernatomicmodelA.ElectronsdonotmoveaboutanatominadefinitepathCanonlypredictwhereanelectronismostlikelytobefound.B.Atomhasasmallpositivelychargednucleussurroundedbyalargeregioninwhichthereareenoughelectronstomaketheatomneutral.Makesupabout99%oftheatomicmassA.ProtonsPositivecharge(1)Thenumberofprotonsdetermineswhattheelementis.(2)Protonnumbersneverchange.(3)AtomicMassUnit(amu)Unitusedtomeasuretherelativemassesofsubatomicparticles;Aprotonhasamassof1amu.(4)AtomicNumberIndicatesthenumberofprotonsfoundinthenucleusofanatom.NeutronsNeutralcharge(1)Neutronnumberscanchange.IsotopesAtomsofthesameelementthathavethesamenumberofprotonsbutdifferentnumbersofneutrons.NeutronsNeutralcharge(2)Mass NumberThesumoftheprotonsandneutronsfoundinnucleusofanatom.(a)DeterminingthenumberofneutronsSubtracttheAtomicNumberfromtheMassNumber(roundthenumber)Makesupabout99%oftheatomicvolume.A.ElectronsNegativecharge(1)Thearrangementofelectronsdeterminesthechemicalpropertiesofanelement.(a)DeterminesthebondingabilityofanatomB.Energy LevelsRepresentsthemostlikelylocationintheelectroncloudinwhichanelectroncanbefound.B.Energy Levels(1)Eachenergylevelcanholdonlyacertainnumberofelectrons(a)1stLevel-2(b)2ndLevel-8(c)3rdLevel-18(d)4thLevel-32(e)5thLevel-50(f)6thLevel-72Valence ElectronsElectronsfoundintheouterenergylevelofanatom.(a)Canhaveamaximumof8electronsintheouterenergylevel.ThenumberatthetopOneortwolettersinthecenteroftheboxBelowthechemicalsymbolThenumberatthebottom1.AtomicNumber2.ChemicalSymbol3.Name4.AtomicMassForcesthataccountforthebehaviorofsubatomicparticles.Electromagnetic ForceA.Forcethatwilleitherattractorrepeltheparticlesonwhichitacts.(1)Particleshavingthesamechargerepel(2)ParticleshavingdifferentchargesattractForcesthataccountforthebehaviorofsubatomicparticles.Electromagnetic ForceB.KeepelectronsinorbitaroundthenucleusNegativelychargedelectronsareattractedtothepositivelychargednucleus.Forcesthataccountforthebehaviorofsubatomicparticles.Strong ForceA.OpposestheelectromagneticforceofrepulsionbetweenprotonsB.KeepstheprotonstogetherForcesthataccountforthebehaviorofsubatomicparticles.Weak ForceResponsiblefortheprocessofRadioactive Decay Aneutroninthenucleuschangesintoaproton.Columns1.CalledGroups18Groups2.ElementswithinthesameGrouphavesimilarbutnotidenticalproperties.A.ElementswithinthesameGroupallhavethesamenumberofvalenceelectrons.Rows1.CalledPeriodsA.7PeriodsPeriodnumbertellshowmanyEnergyLevels2.ElementswithinthesamePeriodarenotalikeinproperties.A.Doesnothaveapattern谢谢你的阅读v知识就是财富v丰富你的人生谢谢！
展开阅读全文