ThePropertiesofWater教案

1、精品推荐范文学习The Properties of Water 教案Unit13ThePropertiesofwaterTeachingGoals.Talkaboutwaterandtheocean.2.Practicecommunicativeskills.3.ReviewmodalVerbs.4.writeanexplanationparagraph.TheFirstPeriodTeachingAims: .Learnandmasterthenewwordsandtheusefulexpressionsoft hispart.2.Learnsomethingaboutwaterbydoin

2、gexperiment.3.Dosomelistening.4.Improvethestudents speakingabilitybytalking.TeachingImportantPoints: .makethestudentsbefreetotalkaboutwater.5.Improvethestudents listeningabilitybylistening.TeachingDifficultPoints: .Howtofinishthetaskofspeaking.6.Howtoimprovethestudents listeningability.Teachingmetho

3、ds: .Listening-and-answeringactivitytohelpthestudentsgot hroughwiththelisteningmaterial.7.Individual,pairorgroupworktomakeeverystudentworkinc lass.TeachingAids: .themultimedia8.theblackboard9.anemptyglass,abottleofwaterandabottleofvegetableoilTeachingProcedures:Step1GreetingsandLead-inReadashortpoem

4、andguessitsname:AletterfromDearUser,Shametoyouall,theIgnorant,IamyourlifeButyouseemnottovaluemeGivemealltherespectForinmeiseternallifeIfyoucontinueabusingmeSurely,allformsoflifewillwitherawayHaveyoueverimagined,Lifewithoutme?Itellyou,itwillbeunbearableThinktwiceForeverydropcounts.Qs:1)whatdoes “ Dea

5、ruser ” herereferto?2)whatdoesittalktoitsusers?3)onwhichplanetdoesitexist? ontheearth,whichisalsocalledthewaterplanet.4)Doyouknowwhyitiscalled“ ThewaterplanetBecauseaboutthreequartersoftheearthiscoveredbywater.Step2:Pairwork:collectasmanywordsaspossiblerelatedt owater.Qs:Howmuchdoyouknowaboutwater?I

6、sallwaterfreshorsalty?Step3:Talkaboutthepropertiesofwater.PairworkT:waterisaroundusandinsideus.wecan tgowithoutwater.Qs:whyiswatersoimportanttolivingthings?canyoupointoutsomeofitspropertiesorcharacteristics?Suggestedvocabulary:It'scolorless,tasteless,odorlessanduniversaldissolv ent.Itfeelswet;It

7、existsinthreeforms:liquid,solid,gas,andiscycledth roughthewatercycle;Itcanabsorbalargeamountofheat;Itstickstogetherintobeadsordrops;It'spartofeverylivingorganismontheplanet;etc.2.GroupworkLearnmoreaboutwaterspropertiesbydoingsomesimpleexperimentsandlearntode scribeanexperiment.whatpropertyofwate

8、rdoeseachofthefourexperimentsillu strate?whatcausesthisphenomenon?what sthisphenomenonrelatedto?Experiment1showshowairpressurecausesapieceofthickpa pertoclingtoanupturnedglassofwater.Experiment2illustrateshowsubstanceswithdifferentden sitybehavewhenplacedinthesamecontainer.Experiment3isanexampleofho

9、wwaterdissolvessubstances andobjects.Experiment4illustratessomeofthedifferencesbetweensa ltwaterandfreshwater.3.T:whatotherpropertiesofwaterdoyouknowabout?whatcausesthefollowingphenomena?canyouexplain?wecangetalotofnutrientsbydrinkingwaterandhavingsoup. woodfloatsonwaterwhileironsinks.Thecoastalarea

10、sareoftenneithertoohotnortoocold.whycansomelivingthingsliveatthebottomoftheoceanwher ethereisnosunshine?Tryaskingquestionsaboutthepropertiesofwaterandtheng iveanswerstothem.Step5:HomeworkReadthetextcarefullyandfindoutthedetailedinformatio naboutwaterproperties.2Thinkasmanyexamplesaspossibletoillustr

11、atewaterprope rties.TheSecondPeriodTeachingAims:.Learnandmasterthesomenewwordsandphrases.2.1 mprovethestudents readingability.3.Enablethestudentstorealizethatitisimportanttoprot ectthewateronourplanet.TeachingImportantPoints:.Improvethestudents readingability.2.masterthefollowingphrases:alltheway,th

12、atis,mixwith,takeadvantageof,managetodoTeachingDifficultPoint:Howdowemakethestudentsunderstandthereadingpassagebe tter.Teachingmethods:.Discussionbeforereadingtomakethestudentsintere stedinwhattheywilllearn.2.Fastreadingtogetageneralideaofthetext.3.Discussionafterreadingtomakestudentsunderstandwha t

13、they velearnedbetter.4.carefulreadingtogetthedetailedinformationinthetext.TeachingAids:.themultimedia2.theblackboardTeachingProcedures:Step1GreetingsStep2RevisionandLead-inAsksomeonetoillustratewaterproperties.Step3:Pre-readingLookatthetitlesinthetextbelow.Donotreadthewholetext.Pickoutthesubjectofea

14、chparagraph.Usethestructuresb精品推荐范文学习精品推荐范文学习elowtomakesixquestionsrelatedtothesubjects.whatis/are?whatdoeslooklike?whataredifferentpartsof?whatcanbecomparedto?Howdoeswork?whataresomeexamplesof?Skimtofindthewordsandphraseswhichdescribethepropert iesofwaterinthereadingtext.ScantoFindoutsomebasicfacts

15、aboutlifeintheoceans.Lifeonearthbeganintheoceansaboutthreebillionyearsag o;99%ofthelivingspaceonearthisintheoceans;Thereareaboutfivemillionspeciesintheoceans;Lifeintheoceansrangesfromtinyplanktontogiantwhales.T:yesterdayyouwererequiredtoaskmorequestionsaboutwa ter spropertiesandfindoutthedetailedinf

16、ormationaboutwat 精品推荐范文学习精品推荐范文学习erpropertiesaswell.Sonowletshavealittlequizaboutthepropertiesofwater.Trueoffalsequestions:)waterisaliquidatroomtemperature,andithasarelatively highfreezingpoint.2)Thereasonwhywatercandissolvemostsubstancesonearthis thatwaterhashighheatcapacity.3)Likealltheothersubsta

17、nces,watergetssmallerwhenitfreezes.4)Purewaterhasahigherfreezingpointandlighterthansaltw ater.5)Thesalinityoftheearth soceansisabout3.5%.6)whenwaterfreezes,itsdensityincreases. 7)otherrecoursessuchasoil,gas,goldetcisaspreciousasad ropofrain.Step4.while-readingAsweallknow,charlesDarwinisfamousforhis

18、“ TheoriginofSpecies ” .Qs:1)wasthereanylifeontheearthbillionsofyearsago?2)Ifany,whatwastheoriginallifelikeatthattime?3)wherediditlive? Inthedeepblueseas.4)Howdoestheworldtakeitsshape,whichisquitedifferent fromwhatitusedtobe,especiallythosevariousorganisms? Billionsofyears naturalselection.2 Itissai

19、dthat99%ofthelivingspaceonearthisintheoceans.Qs:1)whatdoesthisfactresultin? marinelifeisincrediblyrichandvaried.2)canyougivesomespecificnumbersorexamples?Thereareaboutfivemillionspeciesintheoceans.Theyrang efromthetiniestplantsallthewayuptogiants.3)whatdoesthisfactimply?Doyouagree? waterisanexcellen

20、tmediumforlife.4)whydoyouagreethatwaterisanexcellentmediumforlife? waterisaliquidatroomtemperatureandhasarelativelyhig hfreezingpoint;Alllivingcreaturesneedfoodtosurvive,butonmanyoccasi onsthenutrientsbecomeavailabletolivingthingsonlywhe ntheyaredissolvedbywater.3 Soweknowtha

21、toneofwaterspropertiesisitsdissolvability.Qs:1)Doyouknowwhatgiveswatersuchauniqueproperty? Thechemicalstructureofwater.2)whatdoesthewatermoleculelooklike?Awatermoleculeconsistsoftwohydrogenatomsandoneoxyge natom.Thetwohydrogenatomsarebondedtooneoxygenatomto forma'V'shape.Thetwohydrogenatomsf

22、ormapolarmolecule ,thatis,onewithaslightlypositiveendandonewithasligh tlynegativeend.3)canyougivesomeotherexampleswhicharealsoresultedfr omwater suniquechemicalstructure? Plantscanpullwateruptheirrootsviaacapillaryprocess; wecangetalotofnutrientsbydrinkingsoup.That swater sanotherproperty dissolvabi

23、lity.4.Sincewaterissuchauniversalsolvent,itcandissolveju staboutanythingincludingmanygasesandsolids.Asaresul t,thereisseawater.Qs:1)Doyouknowthesalinityoftheearth soceans? about3.5%.2)whatdoesitmean?3)Haveyouevernoticedsuchaphenomenonthatinwinterwate rinsomecontainersorsmallriversoftenfreezeswhileth

24、at inseasnot?canyouexplainit?Thesalinityofseawatercanaffectthefreezingpointofwat er.Seawaterhasalowerafreezingpoint,soevenwhenthetem peratureofseawaterfallsbelow0 ,seawaterisstillliqu id.5.However,nomatterwhetheritisseawaterorpurewater,“woodfloatsonwaterwhileironsinksalwaysworks.Howdoyouexplainthat?

25、whatpropertyofwater isthis?Ifasubstancehasalowerdensitythanwaterdoes,itwillflo atonwater;otherwise,itwillsink.Qs:1)whatisdensity?Andwhat sthedensityofpurewater?Densityistherelationshipbetweenmassandvolumeandisme asuredinkilospercubicmeter.Thedensityofwateris1,000 kg/m3.2)Doesitalsogoforthephenomenon

26、thatIcelookslargertha nwaterofequalmass?yes.watersdensitydecreaseswhenitturnstoice,soitsvolumeincrea ses.3)Doesallthewaterinthesameriveroroceanhaveequaldens ity?Tellyourreasons.No.changesinsalinityandtemperatureaffectwater sdensity.coldwaterofhighsalinityusuallyismostdensea ndwilltendtosinktothebott

27、omoftheocean.6.Qs:1)whatdodifferentdensitiesintheoceanresultin?Densewatersinksandlessdensewaterispushedtothesurfac e.Thuswaterintheoceanisalwaysmoving.2)whatphenomenacanthisresulthelpusexplain?Pleasegiv eexamples.oceanmotionhelpsmovenutrientsaroundandaddsenergytot hemarineecosystems.Differentmarinec

28、reaturesliveindifferentlevelsoftheo cean.7.Readfollowingstatementandthinkwhatconclusionyouca ndraw?orwhatpropertydoesitreferto?Itissaidthatamanof60kglosesabout1Lwaterthroughbreat handskinevaporationeveryday.Inotherwords,539kcalhea tisreleasedinthesetwoways.Ifsomuchheatwerekeptinhum anbody,itwouldraisebodytemperatureby9 .canyouimagi netheresult?waterhasarelativelyhighheatcapacityandcanaccommodat etheclimateautomatica