Unit 1 the roots of chemistry.ppt

化学的溯源化学的溯源TheDefinitionofChemistrynChemistrycanbebroadlydefinedasthescienceofmoleculesandtheirtransformation.nMoleculemlikju:lAgroupofatomsbondedtogether,representingthesmallestfundamentalunitofachemicalcompoundthatcantakepartinachemicalreaction.（化）分子化学可以被广泛地定义为（一门研究）分子及分子间（相互）转换的科学TheDefinitionofChemistrynChemistrystudyofthemattermaterialsoftheuniverseandthechangesthatthismatterundergoes.nMatter-anythingthathasmassandoccupiesspace.nExample:Theappearanceoflife.Thefermentationoffruitjuice.Somechemicalprocesseswerenotunderourcontrol:Forexample,therottingofmeatandfish,andtheburningofwood.Somechemicalprocesseswereunderourcontrol:Forexample,theexperimentsinlab.Fermentationf:mnteinn.发酵Sugarisaddedtothewineduringfermentationtoincreasethealcohollevel.发酵时在葡萄酒里加糖以提高酒精浓度。

TheDevelopmentofChemistryFourperiods:PrehistoricChemistry史前化学（paragraph2）GreekChemistry希腊化学（paragraph3-11）Alchemy炼金术（paragraph12-13）ScientificChemistry科学化学（paragraph14）PrehistoricChemistrynCharacteristic：nMotivatedbythepracticalneedsofpeople.nTheearlybeginningsofchemistrywereclearlymotivatedbythepracticalneedsofpeople.很显然，人类的实际需求推动了早期化学的发展Thefermentationoffruitjuice,therottingofmeatandtheburningofwood.Lateronwelearnedtocontrolchemicalprocessesandtousethemtoprepareavarietyofdifferentproductssuchasfood,metals,ceramicsandleather.ceramicssirmiksleatherlen.1制陶术，陶器制造；陶瓷工艺n.皮,皮革2陶器，陶瓷nThediscoveryoffireofferedthefirstopportunitytoprehistoricpeopletocarryoutcontrolledchemicalprocesses.nTherewerenowrittenrecordsaboutpeopleschemicalskills.nWecanjudgetheirchemicalabilitiesonlyfromthearcheologicaldiscoveriesofvariousartifacts.archeological,:kildikladj.考古学的3000-800BCTransitionfromstonetobronzefortools&artsTurkey,3000-2000B.C.N.Afghanistan,2200-1800B.C.BronzeageBronze:Cu+SnTm950oCGreekchemistrynCommontrait: basedonspeculationratherthanonexperiment.n希腊化学的普遍特点：建立在猜想的基础上而不是实验。

nTheconceptoftheelement元素概念的提出PhilosopherswholivedinMiletus(onthecoastofmodern-dayTurkey)werethemostinfluentialearlythinkers.nThalesofMiletus(582BC)suggestedthatwaterwasthebasicsubstancefromwhichtheuniverseiscomposedandthoughttheearthfloatedonwater.nAnaximanderofMiletus(555BC)challengedThaleswork,heproposedthatairwasthebasicsubstance.nHesuggestedtheprocessesofrarefactionandcondensationforchangefromoneformtoanother.Forexample,aircondensesintowater,andairisformedbyrarefactionfromwater(evaporation).rarefaction,rrfknn.稀薄化，稀释nHeracllitus(540-480BC),whoconsideredfireastheelementofuniverse.nEmpedoclesofAcragas(445BC)believedthattherewerefourelements-earth,air,water,andfire.nHethoughttheseelementscouldcombineinfixedproportionsundertheinfluenceofhigherforcestoformcommonsubstances.nForexample,hesaidthatbonewascomposedoffire,air,andearthintheratio4:2:2.nHeappliedthetermearthtoawidevarietyofsolidsubstances.nUsedtheideaofwatertoindicateliquidsaswellasmetals,sincetheycouldbefused.nAirwasaGreektermforallgases.nHowever,Empedoclesdidthinkoffireasanelementratherthanaprocess. HistoryofChemistryThales-Water泰勒斯认为所有物质都是由一种元素物质组成-水。

Anaximenes-Air安娜希梅内斯认为这种物质是-空气Heraclitus-Fire赫拉克利特认为是-火Empedocles-Princepleoffourelements:water,air,fireandearth.艾姆皮克斯引入四元素原理-水、气、火和土Theterm“element”wasfirstusedbyPlato.(Pra.5)“元素”这一概念第一次是由柏拉图提出的TheConceptoftheElementBasicsubstancePlato427BC-347BCnPlatoisoneofthemostimportantGreekphilosophers. TheStructureofMatternThefourelementsare“themostexcellentfourbodiesthatcancomeintobeing”.nButhowdotheycomeintobeing?nWhataretheymadeof?nPlatosansweristhattheyareallmadeoftriangles,andconstructedinsuchawayastoexplainhowthetransmutationofelementsispossible.nTheconstructionoftheparticlesisdescribed.nTheparticlesareidentifiedwiththefourelements.nFire:aparticleoffireisatetrahedron(4-sidedsolid).nAir:aparticleofairisanoctahedron(8-sidedsolid).nWater:aparticleofwaterisanicosahedron(20-sidedsolid).nEarth:aparticleofearthisacube(6-sidedsolid).nPlatostheorydoesnotallowfortransformationofearthintootherelements.nTheproblemhereisthatthevolumesofthepolyhedrainPlatos“equations”dontaddupcorrectly.nE.g.,considerthe“equation”:1W=3F+1Awhichtellsusthatonewateratomcanbeconvertedinto3fireatomsandoneairatom.(Thereare20equilateraltriangles,t,involvedinthisequation.)Theproblemisthatthevolumeofonewateratom(i.e.,oneicosahedron)ismuchgreaterthanthecombinedvolumesof3fireatoms(3tetrahedra)andoneairatom(oneoctohedron).nThetransformationofelementsseemstoviolatetheprincipleofconservationofmatterEulersFormula:V-E+F=2nForanyconvexpolyhedron,thenumberofverticesandfacestogetherisexactlytwomorethanthenumberofedges.SymbolicallyV-E+F=2.Forinstance,atetrahedronhasfourvertices,fourfaces,andsixedges;4-6+4=2.verticesv:tisi:zn.顶点convex凸面的Aristotle384BC-322BCHeacceptedtheideaoffourelement,butintroducedtheconceptoftransmutationofelements.Aristotlethoughtthattheelementscouldbeobtainedbycombiningthepairsofopposingfundamentalpropertiesofmatter.AgeneralizationoftheaboveideasonelementswasputforwardbyAristotle.(Pra.9)以上关于元素的观点的概括是由亚里士多德提出的。

Hotnessandmoistnessproducedair.Moistnessandcoldnessgavewater.Coldnessanddrynessproducedearth.Thesepropertieswer。