unit13period1NSEFC课件
日期：2010-05-12 05:52
thatis，ithas____AtwonegativeandonepositiveendBonenegativeandtwopositiveendConenegativeandonepositiveend4Ifyoupourwaterandvegetableoilintooneglass，seawaterorpurewater?ASeawaterBPurewater8Putanicecubeinaglassofpurewater，Unit13ThewaterplanetItisveryimportanttoalltheanimalsandplants It’salsoimportanttohumanbeingsIt’saliquidatroomtemperatureEverydayyoukeepintouchwithit Youcan’tlivewithoutit (Athing)Guesstheriddle:What’sthis?1Whatstateiswaterinatroomtemperature?AliquidBsolidCgas2Thechemicalstructureofwateris_____AtwohydrogenandoneoxygenatomBtwooxygenatomsandonehydrogenatom3Thewatermoleculeispolar，whathappens?AOilfloatsonthewaterBWaterfloatsontheoilCTheymixtogether5Willchalkbedissolvedifyouputitintowater?AYesBNo6Doestheseafreeze?AYesBNo7What’sheavier，whathappe，
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