weathering mechanical weathering chemical weathering oxidation
Weathering 5 Lesson - Earth Science Lesson.pdf · Page 5 of 6 Lesson 5 Weathering Competition Prior...
Transcript of Weathering 5 Lesson - Earth Science Lesson.pdf · Page 5 of 6 Lesson 5 Weathering Competition Prior...
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Lesson5WeatheringCompetition
Weather ing Instruct ional Case: A ser ies of s tudent-centeredsc ience lessons
Lesson5SuggestedTimelineTwo45-minuteperiodswithone24-hourperiodinbetweenforsoakingovernight.
Materials
• Plastic,widemouthscrewtop12-16oz.bottles-1pergroupof4students
• 4Scaleswith0.1gaccuracy-• Marblechip(orothercarbonaterockthatissolubleinvinegar)about1-2inchesacross-1Pergroupof4students
• Plasticspoon–1Pergroupof4students
• Timer-1Pergroupof4students• Plasticorpaperbowl-1Pergroupof4students
• PaperTowels• SafetyGoggles• Vinegar• SeltzerWater• Smallgravel(fishtankgravelorother)
• -Salt• -Sand• -Plasticportioncups(3oz)• -Plasticcups(8oz)• -Largewastecontainer
WeatheringCompetitionSummaryThisisaculminatingactivitythatisusedattheendoftheweatheringunitafterstudentshavelearnedaboutphysicalandchemicalweathering.Thisactivityissetupasacompetitionwheregroupsofstudentsaregivenasmallpieceofmarbleanddifferentweatheringagentstoseewhocanreducethemassoftherockthemostina24hourperiod.Studentsmaychooseoneliquid(vinegar,seltzerortapwater)andonematerial(gravel,sandorsalt)toacceleratetheweatheringoftherocksample.
Objective
• Identifyfactorsthataffectratesofchemicalandphysicalweathering• Predictwhichfactorswillaffecttherateofweatheringinarealrocksampleandexplainhoweachselectedfactorwillaffectrock
• Createaclassbargraphtodisplaygroupdata• Analyzeclassgraph• UsetheC-E-Rformattoexplaintheirthinkingbehindtheirhypothesisandresults
TeacherBackgroundKnowledgeTherearetwotypesofweatheringprocesses:chemicalandphysicalweathering.Chemicalweatheringinvolvesthechemicaltransformationofmineralsandcommonlyresultsinthedissolutionofmineralsinarock.Physicalweathering(alsoknownasmechanicalweathering)istheresultofphysicalforcesthatbreakrockintosmallerandsmallerpieceswithoutchangingtherock'smineralcomposition.Althoughwecommonlyconsiderweatheringanderosionasseparateprocesses,theyoccursimultaneouslyontheEarth’ssurfaceandmayaidoneanother.Inthisactivity,studentswill“weather”theirrocksampleusingachoiceofagents.Therockchosenforthisactivityiscomposedofthemineralcalcite.Calciteissolubleinweakacidsandwillreadilydissolveinavinegarsolution.Thisportionoftheactivityisanalogoustochemicalweatheringandthevinegarwillhaveagreatereffectthanwaterorseltzer.Studentsalsowillhaveachoiceofmaterials(salt,sandorgravel)toputintothebottlewiththesampleandliquid.Gravelisthemosteffectivechoicesinceitwillabradethesampleduringshakingofthebottle.Theshakingofthebottleandtheinclusionofanothermaterialisanalogoustophysicalweatheringsuchasthetransport(erosion)ofsedimentinariver.Theresultsoftheactivityshouldindicatethatthemosteffectiveagentsforweatheringareacid(vinegar),gravel,andvigorousshaking.
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Lesson5WeatheringCompetition
PrepDay11. Labelplasticjarswithperiod
andgroupnumber2. Maketraysofmaterialsfor
eachgroupthatincludethefollowingforeachgroup:1plastic,widemouth,screwtopjar,Electronicscalewith0.1gaccuracy,andtimer.
3. Identifyaneasilyaccessiblelocationtosetupavariablestationwithpremeasuredplasticportioncupsofeachofthesolidvariables(sand,gravel,salt),and8ozcupsofeachoftheliquidvariables(tapwater,seltzerwater,vinegar).
4. Createandlabeltraysbyperiodforstudentstosettheirbottlesonaftertheexperiment.
Day25. Preparetraysofmaterialsfor
eachgroupincluding:Jars(withrocksandvariables),funnel,plasticbowl,plasticspoon,scale,calculator,andpapertowels
6. Designateacentrallocationforthelargewastecontainerforstudentstopourtheirliquid/solidmixtures(sotheydonotgointhesink)
7. Technology(ifpossible):DocumentcameraorPowerPointslidetoprojectworksheetinstructionsandgraphofclassresults.
Setupofliquids(seltzerwater,waterandvinegar)
Funnel,electronicscale,Setupofsolids(gravel,sandandsalt)Timer,emptybottles
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Lesson5WeatheringCompetition
PreparationofMaterialsThebottlesusedintheweatheringcompetitionshouldbesturdyplasticbottleswithawideopeningandscrewtoplidthatare12-16oz.insize.Sportdrinkandjuicebottlesworkwellforthisactivity.Avoidglassbottlessincetheymaybreakduringvigorousshaking.TherocksampleusedintheWeatheringCompetitionshouldbeacarbonaterock(composedofthemineralcalcite)thatwillreacttoaweakacidsuchasvinegar.Whitelandscaperockcomposedofmarbleworkswellforthisactivity;thismaterialisreadilyavailableinhardwarestoresandplantnurseriesin20poundbags.Sincesomemarblesmaybecomposedofthemineraldolomite(thatislesssolubleinvinegar)ratherthancalcite,itisimportanttotestthesolubilityofthesampleinvinegarbypre-runningtheactivity.Alternatively,limestonesamplesmayalsobeusedinthisactivityiftheyarecomposedofcalciteandaremildlysolubleinvinegar.Itisalsoimportanttousesamplesthataresmallenoughtofitthroughtheopeningofthebottle.
Ordinarywhitevinegarmaybeusedfortheexperiment.Typically,whitevinegarhasanacidityof~5%.Inordertopreventthecompletedissolutionofthesample,itisadvisabletodilutethevinegarbyaboutone-halfwithtapwater.Thiscanbedoneaheadoftimesothatthestudentsdonotneedtobeconcernedaboutan
Sportdrinkbottlewithwideopeningandscrewtoplid
Whitemarblelandscaperock
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Lesson5WeatheringCompetition
Standards12
NGSSPerformanceExpectations:ThislessonsupportsstudentsinprogressingtowardtheNGSSPerformanceExpectation.MS-ESS2-1.DevelopamodeltodescribethecyclingofEarth'smaterialsandtheflowofenergythatdrivesthisprocess.[ClarificationStatement:Emphasisisontheprocessesofmelting,crystallization,weathering,deformation,andsedimentation,whichacttogethertoformmineralsandrocksthroughthecyclingofEarth’smaterials.]MS-ESS2-2.ConstructanexplanationbasedonevidenceforhowgeoscienceprocesseshavechangedEarth'ssurfaceatvaryingtimeandspatialscales.[ClarificationStatement:EmphasisisonhowprocesseschangeEarth’ssurfaceattimeandspatialscalesthatcanbelarge(suchasslowplatemotionsortheupliftoflargemountainranges)orsmall(suchasrapidlandslidesormicroscopicgeochemicalreactions),andhowmanygeoscienceprocesses(suchasearthquakes,volcanoes,andmeteorimpacts)usuallybehavegraduallybutarepunctuatedbycatastrophicevents.Examplesofgeoscienceprocessesincludesurfaceweatheringanddepositionbythemovementsofwater,ice,andwind.Emphasisisongeoscienceprocessesthatshapelocalgeographicfeatures,whereappropriate.] AssessmentBoundaries:Assessmentislimitedtotheinteractionsoftwosystemsatatime.Inthislesson…
ScienceandEngineeringPractices DisciplinaryCoreIdeas CrossCuttingConcepts
AnalyzingandInterpretingDataStudentsusegraphicaldisplaysofthemulti-variablechartstoidentifythecorrelationalrelationshipsinthedata(betweenthesolidvariablesandliquidvariables).Studentsanalyzeanddeterminesimilaritiesanddifferencesinthefindingsastheytabulateclassdata.UsingMathematicsandComputationalThinkingApplymathematicalconceptsand/orprocessesofpercentandratiotocalculatethepercentchangeinmassfrombeforeandafterthe‘shaking’.
ESS2.A:Earth’sMaterialsandSystemsTheplanet’ssystemsinteractoverscalesthatrangefrommicroscopictoglobalinsize,andtheyoperateoverfractionsofasecondtobillionsofyears.TheseinteractionshaveshapedEarth’shistoryandwilldetermineitsfuture.ESS2.C:TheRolesofWaterinEarth'sSurfaceProcessesWater’smovements—bothonthelandandunderground—causeweatheringanderosion,whichchangetheland’ssurfacefeaturesandcreateundergroundformations.
EnergyandMatterStudentslearnthatwithinanaturalordesignedsystem,thetransferofenergydrivesthemotionand/orcyclingofmatter.Inthiscase,itwastheenergyofmotion(shakingthewaterbottles)thatmodeledanexpeditedagentofweatheringthemarblerocks.StabilityandChangeStudents’modelsofthedifferentchemicalandmechanicalweatheringagentsdemonstratechangesinmassovera24-hourperiod.
Inthislesson…
CCSSMathematics CCSSEnglish-LanguageArtsCCSS.MATH.CONTENT.6.RP.A.3.CFindapercentofaquantityasarateper100(e.g.,30%ofaquantitymeans30/100timesthequantity);solveproblemsinvolvingfindingthewhole,givenapartandthepercent.
CCSS.ELA-LITERACY.RST.6-8.7Integratequantitativeortechnicalinformationexpressedinwordsinatextwithaversionofthatinformationexpressedvisually(e.g.,inaflowchart,diagram,model,graph,ortable).
1NGSSLeadStates.2013.NextGenerationScienceStandards:ForStates,ByStates.Washington,D.C.:TheNationalAcademiesPress.2NationalGovernorsAssociationCenterforBestPractices,CouncilofChiefStateSchoolOfficersTitle:CommonCoreStateStandards(insertspecificcontentareaifyouareusingonlyone)Publisher:NationalGovernorsAssociationCenterforBestPractices,CouncilofChiefStateSchoolOfficers,WashingtonD.C.CopyrightDate:2010
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PriorKnowledgeIngrades3-5,studentslearnedthatwater,ice,wind,organisms,andgravitybreakrocks,soils,andsedimentsintosmallerpiecesandmovethemaround.StudentshavealsolearnedthatmostofEarth’swaterisintheoceanandmuchoftheEarth’sfreshwaterisinglaciersorunderground.Inpreviouslessons,studentshavelearnedaboutmechanicalandchemicalweathering.Theyhavereceivedinquiry-basedinstructionanddirectinstruction.Studentshavealsoconductedtheirownexperimentsandusedmodelsastoolstodemonstrateobservableandunobservablephenomena.
LessonPrelab
1. DividestudentsintoteamsoffourandpassoutworksheetsforPrelab2. Introducethemainquestion:Whataffectstherateoftheweatheringofarock?3. Explainthegeneraloverviewoftheactivityandtherules.Overview:“Eachgroupofstudentswillbe
givenamarblerockandabottleandwillhave24hourstotrytoreducethemassoftherockthemost.Eachgroupselectsdifferentvariablesthatmayincreasetherateofweathering.Rules(listedonstudentsheets):
a. Youmustuseyoursafetyglasses.b. Youwillhave24hours,andbottlescannotleavetheclassroom.c. Therockmuststayinsidethebottleatalltimes.d. Asagroup,chooseonevariablefromeachlist(liquidandsolid).e. Afteryouhaveclosedthecontainer,youcannotopenitupuntilinstructedonDay2.f. OnDay2youmaynotshakeyourcontainer.g. OnlytheMaterialsManagermaygetoutoftheirseat.
4. Instructthegroupstoreadthroughthelistofsolidandliquidvariablesandchooseoneliquidandonesolidvariableandwriteitinthetable.Explainthatseltzerwateriscarbonated,andthereforehascarbondioxideinit.(Tomakesuretherearearangeofchoices,youcanlimitthenumberofgroupsthatchoosethesamevariable.Forexample,inaclasswith9students,only3groupscouldhavethesameliquidandonly2groupscouldhavethesameliquidandsolid.It’salsoimportantforresultstomakesurethatatleasttwogroupschoosevinegar,andthatthesegroupschoosedifferentsolidvariables.However,donotletstudentsknowthatthevinegarisanimportantvariabletorepresent.Ifnecessary,theteachercansetupanextraexperimentalbottle.)
5. Oncestudentsselectvariables,groupsdecideontheagentofweatheringtheyaremodeling(theymayselectmorethanoneagentforeachvariable),andindicatethisontheworksheet.
6. Instructstudentstochooseandrewritetheirhypothesis.
LabDay1
7. Assignstudentrolesinthegroups:MaterialsManager,Timer,ScaleExpert,Pourer8. Readprocedurealoudwhilemodelingandpointingoutlocationofsharedmaterials.9. Instructgroupstocheckoffstepsastheycompletethem.10. Askmaterialsmanagerstogettraysofmaterials11. Floataroundroomwhilestudentsareworkingandchecktomakesuretheymakeaccurate
measurementsandfollowprocedurecorrectly.12. Aftergroupshavefinished,materialsmanagersbringbottlesandmaterialstraystodesignatedareas.13. Restocktraysandvariablestationbeforeeachclass.
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LabDay2
14. Readprocedurealoudandmodelandpointoutlocationofsharedmaterials.15. Explainhowtocalculatepercentchangeandhowusethecalculator.16. Rotatebetweengroupstocheckandrecordeachgroup’spercentchangeandvariablesused,andaddy-
axisunitsonthegraphtemplate.17. Createclassgraph.Projecttheclassresultsgraphontheboard,andcolorinbarsonthegraphtemplate
toaddthepercentchangeforeachgroup,andcheckoffthevariablesusedforeachgroup.18. Instructstudentstoanalyzethegraphandfillouttheclassresultssection.19. Havestudentscleanupmaterialsandpassoutexitticketforstudentstocompleteindividually.20. Leadclassdiscussionofstudentconclusionsaboutthedata,toconnectresultstopreviouslearningabout
chemicalandmechanicalweathering.
PotentialPitfallsStudentsmaybeconfusedbythenumerousvariablesinvolvedinthisactivity.Itisbesttofront-loadthestudentswiththetwomainpoints:eachgrouphadaliquidvariableandasolidvariabletofocuson.Consideringthedatafromtheentireclass,studentswillseethat(forthisexperiment)theagentthatismosteffectiveatdecreasingthemassoftherocksampleisvinegar.However,allgroupswillhavesomemasslossduetophysicalweatheringduringtheshakingofthebottle.Aswiththepreviouslessonsonweathering,studentsmayconcludethatweatheringisarapidprocesssincetheymaygetdramaticresultsfromtheirexperimentovernight.Althoughmanymineralsaresolubleinacidsolutions,mostgeologicenvironmentsarenotasacidic(lowpH)asvinegar.Thus,dissolutioninthenaturalenvironmentisgenerallymuchslower.Itisimportanttounderstandthatthisactivityisamodelofchemicalandphysicalweatheringandhassomelimitations.Makesurethatstudentsunderstandtherelativetimeframesforgeologicchangeastheyrelatetoweatheringofrock.
Anotherpossiblemisconceptionisthatstudentsmayrevealthattheyconceptualizedifferentshapedandsizedrocksasjustbeingthatway,andhaven’tmadeconnectionstothekeyconceptthatrocksarepartoftheEarth’scrust,andhavechangedovertime,chemicallyand/ormechanically.
Source:GaryHalvorson,OregonStateArchives