Contents:

Quick Reference Sheets:• Intro:How Water Freezes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .page2Experiment:• Freeze Ice Cream . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .page3EquipmentList:• Ice Cream . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .page4Story,Part1:• Evil Mister Fred's Ice Cream . . . . . . . . . . . . . . . . . . . .page5Story,Endin• g . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .page6

Video Transcript:Introduction:• How Water Freezes . . . . . . . . . . . . . . . . . . . . . . . . . . . .page7Story,Part1:• Evil Mister Fred's Ice Cream . . . . . . . . . . . . . . . . . . . .page8Experiment:• Freeze Ice Cream . . . . . . . . . . . . . . . . . . . . . . . . . . . . .page12StoryEndin• g . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .page15

Teacher’s Guide for:

Ice CreamNote: All activities in this document should be performed with adult supervision. Likewise, common sense and care are essential to the conduct of any and all activities, whether described in this document or otherwise. Parents or guardians should supervise children. Rock-it Science assumes no responsibility for any injuries or damages arising from any activities.

Note: All activities in this document should be performed with adult supervision. Likewise, common sense and care are essential to the conduct of any and all activities, whether described in this document or otherwise. Parents or guardians should supervise children. Rock-it Science assumes no responsibility for any injuries or damages arising from any activities.

IceCreamARock-itScienceLessonFilmedJuly,2009

Title Page of Video

NOTE: This is the transcript of a lesson that was videotaped during an actual Rock-it Science class with real students, not actors. The students’ brainstorming comments are included on the video, but are not transcribed here because they’re not part of the lesson presentation.

Rock-it Science2110 Walsh Ave, Unit FSanta Clara, CA 95050www.rockitscience.org

(c) 2012 Rock-it Science Educationally Useful Programs. All Rights Reserved

Rock-it Science Teacher’s Guide Ice Cream -- Page 2

Quick Recap

Lesson Intro: How Water Freezes

Teacherexplainshowwatermoleculescirculateinafreezingpond,theonesatthesurfacedrop-•pingtothebottomastheygetcold,andloweronesrisingtoreplacethem .Asthemoleculesgetcolder,theygetclosertogether,untiltheyfreeze--thentheygetfarapart .•Wateronlyfreezesatthetopofthepond .Thisisgoodforanimalslivinginthepond,becauseif•thewaterfrozeallthewaytothebottom,theanimalswouldfreeze .Ifyoucanputsomethinginbetweenthefrozenwatermolecules,youcantrickthemsothey’llno•longerbeice .Whenicemelts,itscoldnesshastogosomewhere .Whenyoueaticecreamtoofast,youget•brainfreeze .

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Experiment RecapExperiment: Freeze Ice Cream

1 .Checkthetemperatureofabagofice .It’slowerthanthefreezingpoint .

2 .Eachstudentgetsaziplockbagwithascoopoficecreaminside .Theyhavetomeltitwiththeirhands .(Somegetsodaiftheyprefer .)

3 .Teacherputscrushediceintoplasticbottle .Studentsinpairsputintheirsealedbagsandtaketurnsshakingbottleforthreeminutes .

4 .Studentsremovebagstocheck .Icecreamhasn’tfrozen .

5 .Teacheraddsrocksalt .Studentsputbagsbackinandshakeforanother3minutes . 6 .Temperatureofbottleisnowbelowfreezing .

Studentsremovebags,butdonoteaticecream .Ascoopoficecream(orsoda)fromtheoriginalcontainerisgiventothosewhowantsometoeat .

Equipment List: “Ice Cream”

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Items needed for Instructor:

Largebagofcrushedice•Infra-redThermometer•Scoopforcrushedice•ScoopforRockSalt•IceCreamScoop•

Items needed for Students:

Consumables (per student):

IceCream,softened,onescoopperstudent•Assortmentofsodasorotherdrinks,inplaceoficecream•1-qtZiplockbag•Crushedice,onepoundperstudent•Rocksalt,1/4cupperstudent•Smallpapercup•PlasticSpoon•

Other:

1-qtPlasticBottlewithscrew-onlid•Aluminumroastingpan(1panper2or3students)•

Prep Work:

TakeIceCreamoutof•freezeraheadoftimetosoftenBuyalargebagof•crushediceonmorningofclass

Infra-red thermometer being used to check temperature of ice in plastic bottle.

Story Quick Recap

Part 1:

EvilMisterFredisakingwholovesicecreamandhasgrownveryfat .•Hekidnappedtheonlypersonwhoknewhowtomakeicecreamandputhiminacage .•Meanwhile,JackandJillwerelivingaswoodcutters .JillusedabigaxeandJackusedachain•saw .Thechainsawmadelotsofsawdust,whichJackhidinacave .Duringthewinter,Jackdraggedhischainsawoverafrozenpondandcutitintoicecubes,which•healsoputintothecave .Nowit’ssummer .EvilMisterFreddecidedtotravelaroundhiskingdomtomakesurehissub-•jectsweren’tbeinggood .Hewantedtohaveicecreamavailablewhereverhewent .HisminionsattachedthousandsofballoonstoEvilMisterFredinordertogethimoffhiscastle,•sohecouldtravel .Theycarriedtheicecreammaninhiscage .Theicecreammangotsick,sohewrotedowntherecipesosomeoneelsecouldmakeit .•

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Story Quick Recap

Ending (Picture is the same as Part 1 -- no additional drawing was done):

JackandJillknewEvilMisterFredwasonhisway,andtheicecreamwasn’tready .•Jackpanickedandranaroundthecavewithhischainsaw,scrapingtheroofofthecave,which•wasmadeofsalt .AsJackranaround,hemixedupthesaltwiththeicecubes,andtheicecreamfroze .WhenEvilMisterFredarrived,hecouldbarelyfitintothecave .Bythetimehewasfinishedeat-•ingalltheicecream,hecouldn’tgetout .JackandJillslippedaway .

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Part 1 (cont):

Aminiononhorsebackwentonaheadtogivetherecipetothenexttown,whereJackandJill•lived .Justbeforehegotthere,hebumpedintoahiveofbeesandjumpedintoamudpuddletocoverhimselfwithmudandkeepthebeesfromstinging .WhenhegavetherecipetoJackandJill,theingredientswerereadable,butthedirectionsfor•freezingwerewipedawaybythemud .JackandJillmixeduptheingredientsandbroughtthemintothecave,hopingtheicecubes•wouldfreezetheicecream .Itdidn’twork .JackandJillinvitedthesethreetocomealongwiththem,sotheymadesomewheelspopoutof•thebottomoftheirtubandfollowed .EvilMisterFredhasmadetheAbominableSnowmanangry,drilledabunchofholesinthelogto•weakenit,andtoldthetasmaniandevilsthatthepeoplewhoarecominghatetasmaniandevils .JackandJillhavetofindawaytogetpastallofthemtogettoSickTown .•

Transcript: Introduction

Rock-it Science Teacher’s Guide Ice Cream -- Page 7

Canwemakewaterfreezeat100degrees?Usually,waterfreezesrightat32degreesFahrenheit .You’vegotallthesewaterguyshangingaround--theylooklikeMickeyMouse .Andifthere’sasurfacethere,theMickeysareallhangingaroundatthesurface .Andwhenitgetscoldout,theairgetscoldfirst .Whentheairgetsreallycold,itsuckstheheatoutofthewaterguys,andtheystarttogetcolderandcolder .Whentheygetcolder,theygetclosertogether,andtheystarttosinkdowntothebottom .Andnewguyscomeuptothetop .Andprettysoonthenewguysgetcolderandcolder,andtheysinkdowntothebottom .Andanothergroupsofnewguyscomestothetop .Thiskeepsgoingandgoingandgoingandgoinguntiltheygetsocoldthattheydon’tgetclosertogether .Theydosomethingverystrange--theymovefurtherapart .Assoonastheymovefurtherapart,theyfreezeandbecomeice .

Andtheiceworksperfectly .Theiceprotectstherestofthewaterunderitfromgettingfrozen .Doyouknowwhythisisgood?Becauseifthere’safreshwateroctopusdownthere,thenhewon’tgetfrozeninagiantblockofice .That’sreallygood,becauseyoudon’twanttohavefrozenoctopuses .

Now,ifyoucouldsomehowsticksomethinginbetweenthoseguysandmakethemgetfurtherapart,orsomehowmakethemgetclosertogether,youcantrickthem,andthey’llnolongerbeice .They’llturnbackintowater .Canyouthinkofanythingthatwillmakeiceturnbackintowater?

[Student: Heat.]Heatisagoodthing .Whatelsecanyouuse?Salt?Yeah,ifyoucangetsalttofitinbetweenthewaterguys,they’llturnbackfromiceintowater .Yeah,youcouldboilit .There’ssomethingyouputinyourcarstokeeptheradiatorfromfreezing .[Student: Antifreeze.]Yeah,that’sright,it’santi-freeze .Istheresuchathingasuncle-freeze?[Students: Nooo!]

Well,todaywe’regoingtomessaroundwithice .Whenyoumelttheice,itscoldnesshastogosome-where .Soifyouputanicecubeinyourmouth,thecoldnessgoesintoyourhead .Ifyouswallowabunchofice,itgoesintoyourstomach,andthepaingoeswhere?[Student: To your brain.]Intoyourbrain!It’scalledbrainfreeze .Ifyoueaticecreamtoofast . . .Didyouevergetabrainfreezefromeat-ingicecreamtoofast?

Well,weneedacrazystoryandthenwe’lldosomeexperiments .

The water only freezes at the top of the pond.

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Story: “Evil Mister Fred's Ice Cream”Onceuponatime,EvilMisterFredwasaking .Helovedbe-ingkingbecausehecouldeatanythinghewanted .AndEvilMisterFredlikedtoeatfrenchfries,helikedtoeatcreampies,helikedtoeatcreampuffs,andhelikedtoeaticecream(itwasjustinventedinthosedays,bytheway) .Infact,EvilMisterFredkidnappedtheinventoroficecream .

SoweneedacastleforEvilMisterFred,andweneedaforestaroundthecastle,andherearesomegiantredwoodtrees .Herearemoregiantredwoodtrees .Thecastleissobig,youcoulddriveatrainthroughthefrontdoor .

AndEvilMisterFred,ofcourse,evenaftereatingallthiswonderfulfood,usedtositontopandwatcheveything .Heatetoomanyfrenchfries .AndEvilMisterFredlovedtomakedecisions,andoneofhisdecisionswasthathewasgoingtokidnaptheonlyguyintheworldthatknewhowtomakeicecream,andputhiminhisdungeon .Andthatguywouldn’tgettomakeicecreamforanybodyexceptforEvilMisterFred .There’stheicecreamguy,andhe’sinacage .Yeah,we’llmakehimupset .Thereheis,trappedinEvilMisterFred’scage .

AndEvilMisterFreddecidedthathewantedtoseeifevery-bodyinhiscountrywasbeinggoodorbeingbad .Hewantedthemtobebad .Andso,heinvitedpeoplefromeverycitytocometohiscastleandtellhimwhatthey’redoing .Soallthepeoplecamefromeverywhere--thesearepeople--andthepeoplecametothecastle .AndEvilMisterFredsaid,“Whathaveyoubeendoing?”Andtheysaid,“Oh,sir,we’vebeen

reallybad .We’vebeenhittingeachother,throwingrocksateachother,robbingbanks,burningdownhouses,causingallkindsofchaosandmayhem .”Andhesays,“Goodforyou .Yougo .”

Nextperson,hesaid,“Whathaveyoubeendoing?”“Well,we’vebeengood .Wedidn’tdoanythingofthatstuff .We’vebeentreatingeachothernice,growingfood,givingittothepoor .”He’dsay,“Throwtheminjail .”Nextguy .“Whathaveyoubeendoing?”Thoseguyssaid,“Whoa!Okay,we’vebeenbad .”Andeverybodyfromthenon,ofcourse,saidthattheywerebad .ButthenEvilMisterFredsaid,“Idon’tbelieveyou .Throwthemallinjail .”Andeverybodywentrunninglikecrazysotheywouldn’tgetthrowninjail .

AndEvilMisterFredsaid,“Okay,I’mgoingtofindoutformyselfjustwhat’sgoingon .I’mgoingtogofromcitytocityandjustseehowbadtheyare .IfIdon’tseewarandchaosandburningbuildings,they’reintrouble .”

Evil Mister Fred on his castle, with the ice cream man in the dungeon.

The people lined up at the castle.

Rock-it Science Teacher’s Guide Ice Cream -- Page 9

Andhesaid,“Minions,let’sgo!”Andtheminionssaid,“Uh,boss,you’rekindahighupthere .Howarewegoingtogetyoudown?”Andhesays,“Idon’tknow,butifIfallandhurtmyself,it’llbeyourheadschoppedoff .”Andtheminionssaid,“Oops!”

SotheminionsgotthreemillionheliumballoonsandattachedthemtoEvilMisterFred .Millionsofheliumballoons,andnowEvilMisterFredisfloatingonballoons .Andtheyhadtotiearopetohisleg,andalltheminionsgottogetherandtheyheldontotherope .Ittookhundredsofminionsjusttohangontotherope .Andthey’regoingtodraghimfromcitytocity .

AndthenEvilMisterFredsaid,“Waitaminute .Whatareyougoingtogivemeforfood?”Andtheminionssaid,“Idont’know .Youlikeroadkill?”Hesays,“No!Idon’twantroadkill .Iwanticecream .Whereverwego,Iwanticecream,andIwantittobetheverybesticecreamevermade .Taketheprisonerwithyou .”

Sotheminionswentdownandtheygrabbedthecagewiththeprisonerinit,andtheyputthecageontheirheadsandhadhiminside .Andtheguythatknewhowtomaketheicecreamstartedgettingreallysick .Hewasdizzy,hewasseasick,rid-ingaroundontheseminions’heads .Hesays,“Oh,Ican’tgo,I’mgoingtothrowup .”Theminionssaid,“Noooo!”Andtheydroppedthecage .Andhebrokehisanklewhentheydroppedthecage .Andhesays,“Ohhhhh,I’minterribleshape!”

AndEvilMisterFredsaid,“Oh,youguysarehopeless!Youcan’tdoanythingright .”Andthenhesaid,“Chopoffhishead .”Andtheguysaid,“No!Don’tchopoffmyhead!”Hesays,“Howaboutthis--I’llwritedowntherecipeformakingicecream,andthenyoujusttakeitwhereveryougo,andhavesome-oneelsemakeit .Andyoucanguardit .”AndEvilMisterFredsaid,“Yeah,that’saplan .”

Sotheygottherecipeallwrittenout,andtheygaveittoaminion .Andhewasridingonahorse .Andhewassupposedtotakeittothefirsttown .Soweneedahorsehere .Andhe’sgottherecipeinhismustache .Andhe’sheadingofftothenexttown .Thenexttownisupinthehills .Here’sthehills .Upinthehills,there’sallkindsofforestthere .Andtheymakewoodupthere .Doyouknowhowtheymakewood?Theychopdowntrees .AndthepersonschoppingdownthetreesareJackandJill .

Minions attached millions of balloons to Evil Mister Fred and tied a rope to his leg.

Minions carried the ice cream man’s cage on their heads.

Minion on a horse, carrying the ice cream recipe.

Rock-it Science Teacher’s Guide Ice Cream -- Page 10

Jacklikestochopdowntrees,andJilllikestochopthemdownalot .Jillisreallygoodatit .She’ssogoodatchoppingdowntrees,theygaveheranickname .Knowwhattheycalledher?TheycalledherLumberJill .Andshe’sgotabigaxe .Shecanchopdownatreewithoneswing--shoosh!Ahhhhhh--crash!Shewalksuptothenextone--chop!Andit’llallfalldown .

Jacksays,“Oh,Icandobetterthanthat .SohecalledtheAcmeStoreofEverythingandorderedachainsaw .HegoesBrrmmmm!Andhe’soutthere--brrmmm!--sawingthetreesdownwiththat .WhenJillchopsdownatree,itjustfallsdownandthere’ssomebranchesandstuff .WhenJackchopsdownatree,there’sbigpilesofsawdusteverywhere .AndJillsaid,“Youcan’tjustleavethatsawdustaround .You’vegottocollectthatsawdustandhideitsomewhere .”

Hesays,“Okay .”SoJacksweptthesawdustunderarugheputoutthere .Therugkeptgettinghigherandhigher,andJillsaid,“That’snotgood .Findabetterplace .”SoJacklookedaroundandhefoundacave .Hesays,“That’sperfect!I’llputallthatsawdustinthecave .”SoJackgrabbedthatsawdust,putitonawagon,dumpeditinthecave,andthecavewasfullfromtoptobottomwithsawdust .

Andtherewasalakenearby,andJackandJilllikedtogoswimminginthelake .Andinwintertime,let’ssupposeit’swinternow,andthelakefrozesolid .AndJackwasbored .Whatareyougoingtodo?It’swinter,it’ssnowing,andthere’salakeoutthere .Youcouldgoiceskating .SoJackgothischainsawandwentouticeskating .Hedidn’thaveanyiceskates,soJackfireduphischainsaw,puthimselfbackwardwiththechainsawinfrontofhim,touchedthechainsawtotheice,andthezoom-zoomybladelikethiswoulddrivehimbackwardsreallyfast,likesixtymilesanhour,acrossthelake .Nowwhenhegottotheotherside,he’dhitatree,andthe

snowwouldfalldownandburyhiminthesnow .He’ddighimselfout,turnaroundandgobrrrzzzzzandshootbacktheotherway .Well,hehadsomuchfundoingthis,heendedupcuttingthelakeintopieces .Thenhehadtogosideways,backandforththisway .Nextthingyouknow,there’sawholelakeoficecubes,andJacktryingtobalancefromoneicecubetothenext .

Jill with her axe and Jack with his chainsaw and a pile of sawdust.

Cave filled with sawdust.

Jack cut up the pond ice and took it to the cave on a toboggan.

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Imagination and Brainstorming Time

[Students make suggestions](THEREARENOWRONGANSWERS!Whatevertheysay,youshouldreply:“That’sagoodidea,”“Theymightdothat,”etc .Afterbrainstorming,proceedwiththeexperi-ments,thenfinishthestory .)

Okay,we’llleavethis“TobeContinued . . .”

AndJillsaid,“Hey,Jack,that’sperfect .Ilikethat .Let’sputtheicecubesinthecave .Jacksaid,“Youcan’t .It’sfullofsawdust .”AndJillsaid,“Well,digsomeoutandwe’llthrowsomeicecubesin .”SoJackhadtodigoutabunchofsawdust,andtheygotabigsled,atoboggankindofsled,andtheyputtheicecubesonit--bigicecubes .Andtheytookthemovertothecaveandburiedtheicecubesinthesawdust .

Jacksaid,“Well,now,thatwasdumb .Whatareyougoingtodowithabunchofburiedicecubes?”AndJillsaid,“Justwaittilsummerandyou’llsee .”Soallwinterlong,theycuticecubesandthey’dthrowtheminthecave .Prettysoontheyhadacavepackedwithburiedicecubes .

Nowsummer’scome .EvilMisterFredisfloatingtowardJackandJillwithhisballoons .Andtheminionisheadedtowardthem--barump,barump,barump,barump--onahorse .Theminionisn’twatchingwherehe’sgoing .Hefiguresthehorseknowswhereit’sgoing .Hedoesn’thavetowatch,sohe’sfacingbackwardsashe’sridingonthishorse .Andthehorseducksbecausetherewasabeehiverightinfrontofit .Andthebeehivehittheminion--splat!Knockedhimoffthehorse .He’scoveredwithhoney,andhesays,“Oh,boy,honey .”Andthebeesaremad .Nowthey’restingingtheminion--sting,sting,sting,sting,sting--andhe’sgoing,“Ooh,aah,stop,stop,don’tdothat!”Andhestartedrunninglikecrazy,andthebeeswerefollowinghimandstabbinghim,andsotheminionjumpedintoamuddyoldcreek .Andhecoveredhimselfwithmud .Mudworksgreatforkeepingoffthebees .

TheminionhadtowalktherestofthewaytowhereJackandJillwere .AndJackandJillweretheoneswhowerechosentopreparetheicecreamforEvilMisterFred .Theminionshowsupandsays,“Hereyougo .Here’stherecipeforyouricecream .”JackandJillsawthismuddyoldpieceofpaper .Sotheylaiditonaflatrockandtheyscrapedthemudoffthiswayandthemudoffthatway .Andtheycouldreadthetopofthisthing,anditsaid,“Tomakeicecream,mixtogetherabunchofcreamfromacow,honeyfromabeehive,someflavorings,andtoday’sflavoringofthedayisdillpickle .Andthenturnovertoseeinstructionsforfreezing .”Sotheyturneditover,andtheinkwasallgone .Themudhadjustwasheditaway .

Now,JackandJillknowEvilMisterFrediscomingtocheckthingsout .TheyalsoknowthatifEvilMisterFredishappy,hewon’tkillthem .Butifhedoesn’tliketheicecream,andhe’sunhappy--offwiththeirheads!Now,ifyouwereJackandJill,whatwouldyoudo?

Rock-it Science Teacher’s Guide Ice Cream -- Page 12

Experiment: Ice CreamIce .Whattemperatureshoulditsay?[Students make guesses.] It’ssupposedtobe32,rightatthemelt-ingpoint,orzerodegreescelsius .Thiswetice,waterice .Itsays17 .4degreesfahrenheit .Howcoulditbe17 .4?Whatdoyouthink?Rightnow,it’snotmelting .It’sstillcoldfromthefreezer .Thefreezerisfivedegrees,soit’snottothepointwhereit’sstartedtomeltyet .Wheneveritstartstomelt,it’llbe32 .Soit’sgottogetwarmertobe32 .Deeperinthebagit’sabout16 .Sothisiceisprettycold .It’scolderthanthefreezingpoint .Soifweputicecreammixinthere,itshouldfreeze .Wewanttoseeifitreallydoesthat .

We’regoingtogiveyousomeofthisiceandacontainerlikethis .You’regoingtoputmeltedicecreaminwithit .Yourmeltedicecreamisgoingtobeinaziplockbag .Soyou’llhaveicecubesinhere,you’llputyourzi-plockbaginthere,putalidonit .Thesearepaddedlids .Andthen,we’regoingtoshakeitforthreemin-

utes--shakey,shakey,shakey .You’regoingtotaketurnsbe-causeyou’regoingtohaveapartner .Afteryoushakeforthirtyseconds,you’regoingtohandittoyourpartnerandshe’sgoingtoshakeitforthirtyseconds--shakey,shakey,shakey .AndthenI’llsay,“Switch,”andshe’llhanditback .ThenI’llgoshakey,shakey,shakey .AndthenafterthirtysecondsI’llgiveitbackandshe’llgoshakey,shakey,shakey .Andafterthirtyseconds,thenI’lltellyouwhenthethreeminutesareup .

Attheendofthethreeminutes,we’lltakethecapoffandthenyou’llpulloutyourziplockbag .Ifit’sfrozen,itshouldfeelstiff,likeicecreamfeelsstiff .Ifit’snotfrozen,we’lljustcutoffyourheads .No?Okay,wewon’t .Sopickapartner .Iwentandlookedfordillpickleicecream,buttheydidn’thavedillpickleicecream .

Yourjob,whenyougetabagwithicecreaminit,istomeltitwithyourfingers .Oryoucanputitonyourtummy .Some-placesothatitwill[getwarmer .]Yeah,youcanputicecreaminyourarmpit .Isanybodyhereallergictoanythinginthisstuff?Ifyouwantto,youcantrytofreezesomethingelse .

Somepeoplemightwanttofreezeicecream,somepeoplemightwanttofreezesodapop,somepeoplemightwanttofreezewater .Ifyoudon’twanttofreezeicecream,comeoverhere .Makealinerightthere .You’vegotachoiceofvitaminwater,rootbeer,fruitflavorstuff . . .Trytogetmostoftheairoutofyourbagsbeforeyousealthem .

Checking the temperature of the ice.

Scooping ice into plastic bottle.

Rock-it Science Teacher’s Guide Ice Cream -- Page 13

[Instructors scoop chopped ice into plastic bottles and hand out ziplock bags containing a small scoop of ice cream or water, soda pop, etc. Students try to melt the ice cream by pressing the bag with their hands. When it’s melted, they put the bag inside the bottle with the ice and screw the lid on.]

Okay,haseverybodygottheirsfilledup?Nosittingdown,youneedtobestand-ingupsomeplace .[Instructor gives the

signal to start, and students start shaking their bottles. Every thirty seconds, the Instructor yells, “Switch!” and the students hand the bottles to their partners to shake. After three minutes, Instructor gives the signal to stop.]

Bringthembacktothetable .Now,whatyou’regoingtodoisopenthetop,takethebagout,feelandseeifit’sfrozen,anddon’topenthebag .Youcanfeelthroughthebag .Doesany-bodyhaveonethat’sfrozenhard?Isitfrozen?[Students: No!]Everybodyputyourbagbackin .Now,somebodysaidthere’sasecretingredienttomakeicecreamfreeze .[Student: Salt.]Salt .We’regoingtoaddsaltinthere,andsaltisgoingtomelttheicecubes .Wherewillthecoldnessgo?We’llfindout . [In-structor adds a small scoop of rock salt to each bottle.]Onceyougettherocksaltinside,putthelidsbackonandtwiddleyourthumbsuntilit’stime .Afteryougetdoneshaking,we’regoingtocomearoundandmeasurethetemperatureinyourbottlebeforeyouopenit .Sowhenwe’redoneshakingit,justsetitonthetable .Ready,getset,go![Instructor counts the time again as the students shake their bottles.]

Nowbringthembacktothetable,butdon’topenthemupyet .Wewanttomeasurethetemperatureofthebottle .[Instructor uses infrared thermometer to check bottles. Most are around 20 degrees.]Okay,ithastobebelow32toevenstartfreez

Melting ice cream with hands.

Instructor scoops ice cream into ziplock bag.

Shaking the bottle.

After the first round of shaking, the ice cream is still soft.

Adding rock salt.

Rock-it Science Teacher’s Guide Ice Cream -- Page 14

ing .Thecoldestoneherewasabout15 .Isthereanyfrostontheoutsideofyourbottle?Ifthere’sfrostontheoutside,thatmeansit’sfreezingsomeofthemoistureintheair .

Now,we’regoingtoputafewofthesebigtubsout .Dumptheiceinthetubandseeifyoursisfrozen .Ifyoursseemslikeit’sfrozen,youmayriskyourtongueandtrytotasteit .It’llproba-blytastevery,verysalty .Tryitandsee .Justwhat’sinthebag,notwhat’sontheoutsideofthebag .Isitsalty?Actually,it’sveryrareforthesetonotendupallsalty,sowhatwe’regoingtodoisgiveyousomeicecreamoutofthecontainerthatyou

cantaste,orsomedrink .Soifyouwantalittlebitoficecreamoralittlebitofdrinkstuff,comeup .

[Student: What do we do with the ice cream we made?]We’regoingtothrowitaway .

Everyone gets a little ice cream (or soda) to eat, from the original container (not from the ziplock bags).

Checking temperature of the bottle.

Dumping out the bottle to see the frozen ice cream.

End of Lesson

If y0u have questions about this lesson, please ask them through the online Teacher Support Forum on our web site.

Rock-it Science Teacher’s Guide Ice Cream -- Page 15

End of Story * DO NOT * present this part of the lesson until after the experiments![Note: There was no additional draw-ing done for the story ending.]

SoEvilMisterFredisfloatingwiththousandsofballoons,onhiswaytowardsJackandJill’splace .JackandJillweretryingtofreezetheicecream .Theydugaholeinthecavewithallthesawdustandtheicecubesleftoverfromwintertime .Andtheyputthebagsthatthey’dmixedtogeth-erontheice,andtheysaid,“Ihopeitfreezes,Ihopeitfreezes,Ihopeitfreezes .”Butitdidn’tfreeze .Theysaid,“Oh,no .We’reintroublenow .”

AndEvilMisterFredshowedup,andJack,beinginpanicmode,grabbedhischainsawandstartedswingingitaround .He’sinthecaveandhe’sgoingbrzzz,brzzz,brzzz--he’scuttingtheceiling,he’scuttingthesawdust,he’scuttingicecubes,andhe’smakingabigmess .Andluckilyforhim,hedidn’tknowitatthetime,butthetopofthecavewascoveredwithsalt .Andsaltfelldownallovertheicewheretheicecreamwas .Andashewasrun-ningthiswayandrunningthatway,hemixeditallup .AndJillsaid,“Jack!Stop!”AndJacksaid,“No!”Jillranoverandsaid,“Stop!”andmadehimturnoffhischainsaw .Shesaid,“Lookatthis .”Jacksaid,“Whoa--it’shard!That’sreallygood .We’resaved!Yeah!”

Aboutthattime,EvilMisterFredfloatedalongonhisballoons .Andhesaid,“I’mhungry!Where’smydillpickleicecream?”AndJackandJillsaid,“Righthere,your--whateveryouare--youracreage!”He’sbig,likeacreage .“Righthereinthiscave .”AndEvilMisterFredsaid,“Yeah!Minions,putmeinthecave .”AndtheminionstookEvilMisterFred,andhealmostfitinthecaveopening .Andthemin-ionshadtogopush,push,shove,shove,putsomebutteronhim,untilhepoppedintothecave .AndEvilMisterFredsaid,“Yeahhh!”Andheatealloftheicecream .

Ofcourse,EvilMisterFred,aftereatingfivehundredpoundsoficecream,becamebigger,andhecouldn’tgetout .AndJackandJilldecided,“We’dbettergonow .”Sotheywanderedoffandlivedhap-pilyeverafter .Andeverybodyelsedid,exceptEvilMisterFred .