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Weareveryfamiliarwithonepropertyofsubstances:-Theycanexistassolids,liquidsorgases.-Collectivelytheyarereferredtoasthe3StatesofMatterUnderthe“right”conditionssomesubstancescanexistinallthreeforms.Examples:ifyoucoolagasitwilleventuallycondenseandformaliquid.Coolitfurtheranditwilltoformasolid.NameveryfamiliarsubstancethatexistsonEarthinthreeforms.StrongforcesexistbetweenatomsinasolidWeakforces“I’mfree!”StrongforcesexistbetweenatomsinasolidSomepropertiesofaSOLID•Itisnotafluidlikeagasorliquid,i.e.,itdoesNOTFLOW•Itisnotcompressible.Agreatdealofforceisneededtochangeasolidsshape.•Asolidhasadefiniteshapeandadefinitevolume,i.e.,itdoesnottakeontheshapeofitscontainer.•Asolidhasagreaterdensitythanitscorrespondingliquid.WeakforcesSomepropertiesofaLIQUID•Ithasadefinitevolume-Takestheshapeofthecontainerthatitisin,butdoesnotfillacontaineroflargervolume.•Usuallymoredensethanagas.•Lesscompressiblethanagas•Themoleculesofaliquidarepackedmorecloselythanthoseofagas.Thereisan“arrangement”,buttheirarrangementislessregularthanthatofasolid.SomepropertiesofaGAS•nodefiniteshape•expandstofillanycontainer•theyarecompressible,i.e.,ifyoureducethesizeofthecontainerthatthegasisin,thegaswilleasily“fit”thesmallervolume.•moleculesthatmakeupagasarefarapartandaremovingaboutrapidly.“I’mfree!”Icantranslate,VibrateorrotateAnywayIplease!DecreasetheVolumeSolid:Strongforcesexistbetweenatomsinasolid.Liquid:•Themoleculesofaliquidarepackedmorecloselythanthoseofagas.•Thereisan“arrangement”,buttheirarrangementislessregularthanthatofasolid.Gas:•Moleculesthatmakeupagasarefarapartandaremovingaboutrapidly.TheRelationshipBetweenStatesofMatter(andwewillseeshortlybetweenEnergyandMatter)IsgivenbytheKineticTheoryKineticMolecularTheory•Allmatterismadeupofsmallparticleswecallofatomsormolecules(groupsofatomsjoinedtogether)•Thesetinyparticlesarealwaysinmotion.Consideragas;-Thehigherthetemperature,thefastertheparticlesmove;-pressure–atoms/moleculescollidewiththecontainerwalls.•Atthesametemperature,moremassive(heavier)particlesmoveslowerthanlessmassive(lighter)particles.•Theparticlesinagashavegreatdistancesbetweenthem;i.e.,theydonotexperienceattractiveorrepulsiveforcesduetoother.Distancebetweenparticlesdecreasesgoingfromgastoliquidtosolid•compressibilityofagas;incompressibilityofsolids&liquidsAnd…IthastodowiththestateofmatterwecallaGASFirst…weknowthatagivenmassofgasoccupiesAlotmorespace(volume)thansaythecorrespondingLiquid.Second….agasismorecompressiblethanaliquidorsolid.Bottomline….agasismostlyemptyspace.ChangingSTATEdoesnotchangeCompositionormass.ChangingSTATEinvolvesTakingENERGYoutofasystemorPuttingENERGYintoasystemThetypeofenergyisoneweareveryfamiliarwith….ChangingSTATEmeanstobringaboutachangeintheamountofFREEDOMAPARTICLEhasParticlesinasolidhavelittlefreedomParticlesinaliquidhavemorefreedomParticlesinaGAS…havethemostfreedomEvaporation:liquidtogasCondensation:gastoliquidFreezing:liquidtosolidMelting:solidtoliquidDeposition:gastosolidSublimation:solidtogasIncreasingEnergyInputTemperatureSolidLiquidGasMeltingEvaporationEnergyReleasedParticleshavelittletonofreedomParticleshavemorefreedomParticleshavetremendousfreedomPhaseChangesThereare3statesareofmatter….Solid,LiquidandGasgasliquidsolidfreezingevaporationmeltingcondensationsublimationdepositionTheprocessesthattransformonestateofmatterintoanotherareshownbelow.YOUAREFAMILIARWITHMANYOFTHESEPROCESSES.ENERGYISINVOLVEDINALLOFTHESEPROCESSES
本文标题:States-of-Matter
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