时间:2023-06-15 09:28:39
引言:寻求写作上的突破?我们特意为您精选了4篇教案教学设计范文,希望这些范文能够成为您写作时的参考,帮助您的文章更加丰富和深入。
2.掌握钠的化学性质、存在和保存方法
3.认识结构决定性质,性质决定存在、保存和用途的思维方法
4.培养学生的动手能力、观察能力及化学美
二、教学重点:钠的化学性质
三、教学用品
学生实验用品:钠、酚酞、小刀、镊子、滤纸、烧杯、玻片、三脚架、石棉网、酒精灯、火柴等
教师演示用品:钠、酚酞、玻璃钠柱、锥形瓶、漏斗、导管(带尖嘴)、大头针、小灯泡、导线、电源、电极等
四、教学方法:实验探究法
五、教学过程
[引言]在人类已发现的一百多种元素中,有一类原子最外层电子数都为1的活泼金属,由于它们的氧化物的水化物都是可溶于水的强碱,因此,又将它们统称为碱金属。
[板书]第二章碱金属
[设问]碱金属的家庭成员都有哪些呢?(学生阅读课文有关内容后回答,并写出其元素符号)
[过渡]本节课我们就来讨论碱金属中具有代表性的金属——钠。
[板书]第一节钠
[学生实验]请用镊子从你们桌上的试剂瓶中取出一小块钠,并用滤纸吸干表面的液体(注意:不可用手接触),放在玻片上,用小刀切割,并仔细观察新切面的颜色(把切下的一小块钠留在玻片上)。
[设问]你们看到了什么现象?说明了钠的哪些性质?(钠的新切面呈银白色,有金属光泽,能用刀切,说明钠的硬度小)
[板书]一、钠的物理性质
颜色状态硬度熔点密度导电性
[展示]用玻管截取的钠的样品。
[演示]钠的导电性实验。把电极两端插入瓶里的金属钠中,接通电源,可以发现串联在线路上的灯泡发亮,提起电极,灯泡熄灭。(说明钠的导电性很强)
[学生实验]观察留在玻片上钠新切面颜色的变化(钠表面变暗,失去光泽。)
[设问]为什么在密封的玻管内的钠能保持光亮的银白色,而我们刚才切割的钠却不能呢?(玻管隔绝空气,刚切割的钠却与空气充分接触,说明钠与空气中的物质发生了反应)
[板书]二、钠的化学性质
1.钠与氧气等非金属反应
[讲解]Na在常温下可被空气中的O2氧化成Na2O,纯净的Na2O是一种白色粉末。
[教师]请大家写出钠和氧气反应生成氧化物(氧化钠)的化学方程式。4Na+O2====2Na2O(白色固体)
[思考]一块钠如久置在空气中会发生哪些变化?
[教师]下面我们改变钠与氧气的反应条件,观察现象是否同上。
[学生实验]切一小块钠用滤纸吸干表面液体,放在石棉网上加热,观察现象
[请一个同学描述所看到的现象,其他同学补充](钠首先融化成球状,然后燃烧,产生黄色火焰,生成一种淡黄色固体)
[现象分析]钠融化成球状说明什么?(钠的熔点低)生成淡黄色固体说明在加热时钠与氧气生成了一种与氧化钠不同的物质,这种物质是过氧化钠(Na2O2)。
2Na+O2====Na2O2(淡黄色固体)
[思考]根据Na与O2反应生成Na2O和Na2O2的条件,分析比较Na2O与Na2O2的稳定性。
[结论]Na2O2比Na2O稳定。
[讲解]钠与氧气反应条件不同,产生了不同的现象,生成了不同的产物。
[设问]钠除了能和前面所述的非金属单质O2反应外,还能和哪些非金属单质反应?
(学生回忆初中学过的Na与Cl2的反应)
[讲解]另外,钠还可以和硫单质反应,甚至发生爆炸,生成Na2S。
[过渡]钠在空气里很容易燃烧,如果钠着火,能否用水来灭火?
[实验]向你们桌上盛水的小烧杯里滴入几滴酚酞,然后投入切下的一小块钠(注意钠块只要绿豆大小,不要用手接触金属钠),并盖上表面皿,观察发生的现象(浮、熔、游、红)。
[教师]请大家根据上述实验现象,讨论以下问题:
[投影]1.钠为什么会浮在水面上?
2.钠为什么会熔化成一个小球?
3.小球为什么会在水面上游动?
4.滴入酚酞后溶液为什么会变色?
5.保存钠的无色液体是否是水?
[学生讨论及回答]
[教师]通过以上实验及讨论结果,请大家归纳出钠的性质。
[板书]2.钠与水反应
[讲解]由Na与水反应后生成的物质可使酚酞变红可知,Na与H2O反应生成了碱,那么,反应生成的气体又是什么呢?
[演示实验]在锥形瓶中装满水和带有大头针、漏斗和导管的胶塞做Na与水反应的实验,并检验生成的气体。
[教师]由实验现象可知,钠与水反应还生成了H2。
[板书]2Na+2H2O====2NaOH+H2
[投影讨论]1.根据以上实验讨论及分析,你觉得钠的化学活性怎样?并与初中所学金属活动顺序表相比照。
2.分析上面各反应中,Na元素化合价的变化,能否从原子结构方面来说明?
[结论]1.钠的化学性质非常活泼,与金属活动顺序表相一致。
2.钠在上述反应中,化合价均由0价变为+1价,这是由于钠原子的最外层只有一个电子之故,因此,钠在化学反应中易失电子,具有还原性,是一种强还原剂。
[设问]通过对钠的性质的讨论,并参阅课本有关内容,回答以下问题:
[投影]1.钠元素在自然界中以什么形态存在?为什么?主要存在于哪些物质中?
2.怎样保存金属钠?为什么要这样保存?
3.钠有哪些用途?
[板书]二、钠的存在及用途
[学生回答,投影并板书]1.钠在自然界以化合态存在,主要存在于NaCl、Na2SO4等物质中,由于钠的性质活泼,所以须密闭保存,少量钠保存在煤油中。
2.钠的用途
a.制过氧化物
b.Na—K合金用做原子反应堆的导热剂
c.制稀有金属如Ti、Ta、Ni等
d.制高压钠灯
[小结]钠是一种化学性质活泼的金属,在自然界中以化合态存在,有着广泛的用途。
关键词:教学设计;教案
中图分类号:G622 文献标识码:B 文章编号:1002-7661(2014)05-262-01
常常听老师说:“教学设计就是教案”。其实教学设计和教案是有区别的。
根据翻阅的资料和自己的理解,谈谈教案与教学设计的几点区别。
区别之一:概念和对应层次不同
教案又叫课时计划,是以课时为单元设计的具体教学方案,是教学中的重要环节,是指导老师自己上课用的教学内容文本,也是考察一个教师备课的重要依据。从研究范围上讲,教案只是教学设计的一个重要内容。
教学设计是把学习者作为它的研究对象,教学设计的范围可以大到一个学科、一门课程,也可小到一堂课、一个问题的解决。目前的教学组织是以课堂教学为主,所以课堂教学设计是教学设计中运用最多的一个层次。教学设计包括教案、学案、评价方式,甚至学生问题的创设、教具的应用等,所有与教学设计有关的内容都是。教学设计是一个泛化的概念。
区别之二:元素或组成不同
教案一般包括教学目的,教学方法,重难点分析,教学进程,教具的使用,课的类型,教法的具体运用,时间分配等因素,从而体现了课堂教学的计划和安排。
教学设计从理论上来讲,有学习者分析、学习内容分析、学习目标阐明、教学策略的制定、课件的使用分析及教学评价等元素,然而在实际的教学工作中,我们讨论比较多的是学习目标、教学策略和教学评价三个主要元素。
区别之三:表现形式不同
教学设计使用表格的方式最多。教学设计,是准备课,特别是公开课等需要全面考虑的一份文档,附件可能有电子类辅助。
教案就是教学的内容文本,是教学设计的最核心的部分。呈现形式一般地有表格式、课堂实录式、普通文本式等。主要是对教学目标、内容、环节进行备课。
区别之四:教学评价不同
教案在编写过程中评价体现不明显;教学设计则依据教学目标对学生掌握知识、形成能力的状况作出准确而及时的评价,是教学设计中的重要环节。
1.Learnandmasterthefollowingwordsandphrases
anyway,private,signature,brief,foresee,instruct,left-handed,right-handed,tothepoint
2.Improvethestudents’readingability.
TeachingImportantPoints
Masterthefollowingimportantpoints
Words:anyway
Phrases:asfollows,cometo,addone’ssignature,signone’sname,andtakeafalsenametothepoint.
SentencePatterns
1.Itonlyremainsformetopassallthemoney…
2.Nowweknowthat…isdead,doesthatmean…
3….ifthatweretohappen,allthemoneyshouldgoto…
TeachingDifficultPoints
1.Thedifferencebetween“tothepoint”and“offthepoint”.
2.theuseoftheword“anyway”.
TeachingMethods
1.Fastreadingtogetthegeneralidea.
2.Carefulreadingtoanswerthedetailedquestions.
3.Individual,pairorgroupworktomakeeverystudentworkinclass.
TeachingProcedures
Step1Revision
1Checkthehomeworkexercises.
2Asktheclassafewrapidquestionsaboutthestoryinthepreviouslesson:
Whatisthenameofthefamousdetective?(J.J.Coal.)Whocametovisithim?(TomGoode.)
WhodiedinTom''''sfamilynotlongago?(Hisaunt,Mrs.Flower.)WhywasMrs.flowersowealthy?(Herhusbandhadbuiltuphisbusinessandhadleftallhismoneytoherwhenhedied.)WhointhefamilysawClareaftershelefthome?(Onlyherfatherandherstepmother.)WhereandwhendidTomGoodemeetClare?(AtteaaftertheburialserviceofMrs.Flower.)WhoisgoingtogetMrs.Flower''''smoney?(ClareFlower.)WhatdidTomGoodeaskthedetectivetodo?(TocheckoutClareFlower.)
Step2Presentation
SBPage51,Part1.GetSstotalkaboutthepictureanddescribewhattheycansee.Askthemwhattheythinkishappening,butdonotanswer“Right”or“Wrong”.
Step3Readingforgeneralunderstanding
Readaloudthetwogeneralcomprehensionquestions.AllowtheSsenoughtimetoreadthetextanddiscusstheiranswersinpairs,thenchecktheanswerswiththeclass.(1Sheistakenawaybythepolice;shehaspretendedtobeClareFlower,buthernameisreallyHopeDarwin.2Themoneyisgiventoanorganizationforhelpingtheblindcalled“HelpingHand”.)
Step4Reading
WbLesson82,Ex.1.GothroughtheexerciseandmakesuretheSsknowwhattodo.Letthemreadthewholepassagecarefullyandanswerthequestions,workinginpairsorsmallgroups.Checktheanswerswiththewholeclass.
Step5Comprehension
SBPage52,Part2.GetSstoworkinpairsandexplainthemeaningofthephrasestoeachother.
Askfortheanswersfromtheclass.
Answers
1Thelawyer(probably)introducedthedetectivewiththewords“Thisismyassistant”.
2TheonlythingwhichIhavetodonowis….
3youshouldbegivenallthemoneywhichbelongedtoher
4signedhernameonthepieceofpaper
5suddenlyyouthoughtofacleverthingtodo
6exceptherstep-mother(Mrs.Flower)
7Hewassmilingandprobablyhopingthathewouldgetthemoney.
8Thelawyersaidlittleandonlywhatwasnecessary.
Thengothroughthetextandexplainanydifficultlanguagepoints.SeeiftheSscanguessthemeaningoftakeone''''splace,pickout.
Notes:
aPresentatthemeetingwere:Pointouttheinversion.
bunknownman=amanwhomnobodyknew
cWheneveryonehadtakenhis/herplace=Wheneveryonehadsatdown
dstepforward=comeuptomytable/desk
eYournameisClareFlower?:Notethequestion,intheformofastatement,forthepurposeofcheckinginformation:
fpleasesignhere…money:Itisusualforlawyerstogetpeopletosignareceipttoshowthattheyhavereceivedallthemoney.
gIfyoucould…instead:Pointouttheconditionalforminapastsituation.Hope''''sthoughtswere“IfIcanpretendtobeClare,Iwillbeabletogetthemoneyinstead.”
hbetweenthetwoofyou=betweenyou(Hope)andtherealClareFlower.
iPerhapsyouwillexplain…why=Pointoutthepoliteform.Moredirectly,thedetectivecouldsay“Whydidyouchangethecolourofyourhair?”
jIpickedoutoneinterestingphotograph=IfoundandbroughtwithmeonephotographwhichIthoughtwasinteresting.
kJustnow=amomentago
1foresee=imaginesomethinginthefuture
Step6Readingaloud
SpeechCassetteLesson82.PlaythetapeofthepassagefortheSstolistenandfollow.Playthetapeofpartofthepassageoncemore;thistimetheSslistenandrepeat.Asmuchofthispassageisindialogueform,youmaychoosetospendlongerthanusualonthisreadingaloudactivity.PuttheSsingroupsoffourandgetthemtoreadthedialoguepartsofJ.J.Coal,Clare,thelawyer,TomGoode.
Step7Workbook
WbLesson82,Ex.2.
LettheSsworkonthisexerciseinpairs.TheycandiscusshowtotranslatetheChineseintoEnglish.
Thenchecktheanswerswiththewholeclass.PutdowntheanswersontheBb.
Step8Consolidation
SBPage52,Part3.Thepurposeofthistaskisfluencypractice,gettingSstotellastoryintheirownwords.Dothistasknoworalternativelyatthebeginningofthenextlesson,asrevision.
1.Learnandmasterthefollowingwordsandphrases:
step,will,stepmother,afterwards,wealthy,checkout,gothrough,lookinto,buildup,divideup
2.Understandthetextbetter.
TeachingImportantPoints
1.Learnandmasterthefollowing:
Phrase:stepinto,buildup,byhisfirstmarriage,turnup,divideup,checkout,apartfrom
SentencePattern:leavesth.to/withsb.
2.Improvethereadingabilityofthestudents.
TeachingDifficultPoints
Understandthefollowingsentences:
1.InfactitallgoestoClare.
2.…becausesomethingsomewheresmellsfunny.
TeachingMethods
1.Fastreadingtogetthegeneralidea.
2.Carefulreadingtoanswerthedetailedquestions.
3.Individual,pairorgroupworktomakeeverystudentworkinclass.
TeachingProcedures
Step1Revision
1Checkthehomeworkexercises.
2GetSstotellstoriesaboutGandhi.
Step2Presentation
SBPage49,Part1.GetSstotalkaboutthepicturesanddescribewhattheycansee.Askthemwhattheythinkishappening.Teachthenewwordswealthy,step-mother,etc.
Step3Readingforgeneralunderstanding
Readaloudthetwogeneralcomprehensionquestions.AllowtheSsenoughtimetoreadthetextandcomparetheiranswers,thenchecktheanswerswiththeclass.(1ClareFlower,Mrs.Flower''''sstep-daughter.2TomGoode,Mrs.Flower''''snephew;hewantsthedetectivetocheckoutClareFlowerandseewhethershehastherighttogethisaunt''''smoney.)
Step4Reading
SBPage50,Part3.GothroughtheexerciseandmakesuretheSsknowwhattodo.Letthemreadthewholepassagecarefullyandanswerthequestions,workinginpairsorsmallgroups.Checktheanswerswiththewholeclass.
Answers:
1Herhusbandhadbuiltupalargebusinessandleftallhismoneytohiswifewhenhedied.
21984,whenshelefthomeattheageofeighteen.
3OnlyMrandMrsFlower.
4MrsFlower''''spetdog.
5KleggwasveryimportanttoTom''''saunt,MrsFlower.
6ThatitwasMrsFlower''''spetdog,andhaddied.
7HeisnotsureaboutClareFlowerandthinksthatsomethingsmellsfunny.
Thisisagoodtimetodealwithanylanguageproblems.SeeiftheSscanguessthemeaningofbuildup.
Notes:
acigar=alargetubeoftobaccoleavesrolledtogether.Itissmokedlikeacigarettebutislargerandmoreexpensive.
bsteppedintothe…office=walkedintothe…office
cbytheway:Notethisphraseforaddingsomeextrainformation.
dHerhusbandhadbuiltupalargebusiness=Herhusbandhadbeeninchargeofhisownbusinesscompanyandhehadmadeitgrowlarger.
eheleftallhismoneytohiswife=Heinstructedinhiswillthathiswifeshouldreceiveallhismoneyafterhisdeath.
fSoyourauntwasawealthywoman?:Notethequestion,intheformofastatement,forthepurposeofcheckinginformation.
gherwill=alegaldocument,whichispreparedbyalawyerandsignedbythepersonmakingthewillandbytwowitnesses.Whenyoumakeawill,youinstructhowyourproperty,moneyandgoodsshouldbedealtwithafteryourdeath.
hherhusband''''sdaughterbyhisfirstmarriage:
Pointoutthephrasebyhisfirstmarriage.
iShelefthome=Shemovedoutofthefamilyhomeandwenttolivesomewhereelse.
jforthepastfifteenyears=forthelastfifteenyears
khaveseenhersince=haveseenhersinceshelefthome
lturnedupattheservice=arrivedattheservicewithoutsayingthatshewascoming.Beforetheburialofaperson,aburialservice(areligiousceremony)isusuallyheldinachurch.
mafterwards:timeadverb=aftertheservice
ndividedup:Notetheadverbuptoexpressintopieces.Otherexamples:cutup,chopup,tearup.
oDidtheyusetogooutalot:Didtheyusedtogooutisalsoacceptable.IncurrentEnglish,usedtoismoreoftenusedinquestionsandnegativesasaninvariableform.
pThepointis…=Theimportantthingis…
qcheckout=Tofindoutalltheinformationaboutsomeoneorsomething.
rsomething…smellsfunny=Ithinkthatsomethingstrange/dishonest/ishappening;Iamsuspicious.
ssoClarewouldhavebeenfiveyearsold:TomiscalculatingtheageofClare.
tCanyougothroughthem=Canyoulookthroughyouraunt''''spapers
Step5Comprehension
SBPage50,Part4.LettheSsdothisexerciseindividually,thenchecktheiranswersinpairs.Ifyouwish,thisexercisecanbedoneforhomeworkasconsolidation.
Answers:
1ClareFlowerwasbornin1966.
2Fiveyearslater,ClareFlower''''sfathermarriedagain.
3ClareFlowermovedtoLosAngeles.
4ClareFlower''''sfatherdiedtenyearsago.
5MrsFlowerdiedthreeweeksago.
6WhenMrsFlowerwasburied,Clareturnedup.
7TomGoodespoketoClareFlower.
8TomGoodecalledonthedetective.
Step6Readingaloud
SpeechCassetteLesson81.PlaythetapeofthepassagefortheSstolistenandfollow.Playthetapeofpartofthepassageoncemore;thistimetheSslistenandrepeat.Payattentiontostressandintonation,andthesentencestressoflongersentences.Asmostofthepassageisindialogueform,youcouldspendlongerthanusualonthisreadingaloudactivity.GetSstoworkinpairs;oneplaysthepartofthedetective,theotherplaysthepartofTomGoode.
Step7Notemaking
SBPage50,Part2.GetSstodothisexerciseindividually,sothateveryShastomakeanefforttore-readthetextandextracttherelevantinformation.Ifitisdoneinclass,getSstochecktheirnotesafterwardsinpairs.Alternatively,ifyouwish,youcansetthisexerciseforhomework.Inthatcase,getSstochecktheirnotesinpairsatthebeginningofthenextlesson.
Notes:
ClareFlower:bornin1966;lefthomeattheageof18;haslivedinLosAngelesforthepastfifteenyears.
J.J.Coal:famousdetective;worksinWashington;smokescigars.
ClareFlower''''sfather:Inhisfirstmarriage,hehadadaughter----Clare;marriedTomGoode''''sauntin1971;builtupalargebusinessduringhislifetime;diedtenyearsagoin1989;leftallhismoneytohiswife(TomGoode''''saunt).
ClareFlower''''sstep-mother:TomGoode''''saunt;
marriedClare''''sfatherin1971;hadapetdogcalledKlegg;diedthreeweeksago;hasleftallhermoney(about$4million)toClareFlower.
TomGoode:Handsome;agedabout30;nephewofMrsFlower.
Step8Workbook
WbLesson81,Exx.1-4.
SsshouldgooverthesentencesinEx.1individuallysothateveryonemakesaneffort.Thencollecttheanswersfromtheclass.GetSstocorrectthefalsestatements.
LettheSsworkonEx.2inpairs.ThencalloutSstoreadaloudthecompletedpassagetothewholeclass.
AllowtheSsacoupleofminutestogothroughEx.
3.ThencalloutsomeofthemtogivethecompletesentencesandputthemintoChinese.
BeforestartingtodoEx.4,givetheSsthefollowingexamples:Iusedtosmoke,butI''''vegotridofthehabitnow.(to+do)Iamquiteusedtothehotanddampweatherinthesouth.(to+noun)WhentheSsunderstandwhattodo,getthemtomakesentences.Setthisforhomeworkifthereisnotenoughtimeinclass.