PHYSICS AND CHEMISTRY d
n
2
ESO
Enrique Andrés del Río Miguel Ángel Yuste Muñoz Ángel Rodríguez Cardona Antonio Pozas Magariños
Pedagogical Advisors
Juan Carlos Fajardo Gómez Alicia SampedroMontañés
MADRID · BUENOS AIRES · CARACAS · GUATEMALA · LISBOA · MÉXICO NUEVA YORK · PANAMÁ · SAN JUAN · BOGOTÁ · SÃO PAULO · AUCKLAND HAMBURGO · LONDRES · MILÁN · MONTREAL · NUEVA DELHI · PARÍS SAN FRANCISCO · SIDNEY · SINGAPUR · SAINT LOUIS · TOKIO · TORONTO
Unit introduction
HOW OW TO USE THIS BOOK
THE PROPERTIES OF MATTER
CHALLENGE Wearegoing to createa small rainbow of coloursina glass. You will need:syrup, honey, sunflower oil, oliveoil, water and alcohol. Wearegoing to mixeverythingin a champagneglassusing a spoon. 1. Pour somesyrup nthe i glass, usingthe spoonto help you. 2. Add alittlehoney. 3. Add a littlewater. 4. Add sunflower oil andthenolive oil. 5. Finally, pourinsome 96%alcohol. Answer thefollowingquestions: f) If you added theelements ina differentorder, would theresult bethe same? Testit. g) Canyou explainwhathappened?
Introductory text which presents each unit and relates it to your world. The list of contents shows you what topics each unit will cover.
Go to the Online Learning Centre to download the accompanying worksheets for this section.
Development Dev elopment of content Learning will be fun with this book. The theory is presented in clear, concise text accompanied by images and infographs. This visual format will make it easier for you to understand everything.
THINK AND REASON
Situationsto awaken your curiosity and motivate you to learn.
Wecalculatethevolumeof anobjectdifferentlydependingon itsshape. If it hasa regular shape, suchasa sphereor a prism, wecan calculateitsvolume mathematiicallywith callywith thecorrespondingformula. r
V=
·r 2 · h
π
V=
r
h
4 3
· π ·r 3
However, thereare notmanyregular shapesin nature. Normally, shapesare irregular, likea stoneor our ownbodies. How can you calculateyour eyour own volume?
Science in Society
SCIENCE 2.0
Read the articleyou can findat goo.gl/Y3T7bp Writefivethingsthat you do everyday thanks to scientificadvances.
Theevolutionof scienceisan unstoppablefact. Wehavemachines and instruments thatmake our dailylives easier and th hathave athave changed our behaviour. Societyhas continuallychanged andadapted withthe progressof science.
THINKAN D REASON Consider your normal dailyroutine, withall your obligationsand distractions. Now imagine itwithoutyour mobilephone. Would your daybe thesame? Would youbeable to adaptto a lifestylewithoutit? Think abouthow mobilesaffectour lives: Theycancausepeople to be come isolated fromsociety.
Th e yallow u sto con tactother peopleatany time.
Learnhow to do differenttypesof volumemeasurements withthis animation: goo.gl/SLNuxr.
THINKAND REASON
4.1. Advantages and Disadvantages
If you ask your parentswhattheir liveswerelike atyour age, theywill probably tell you thingswereverydifferentthan theyare for you. Ifyou ask your grandparents, theanswer will bethe same. Therearemany differences, but there will beone commontheme: society.
SCIENCE2.0
Imagineyou havea bathfilled to the brimwithwater and you climb into it.
InSection4 wetalkedaboutmobilephones.You probablynoticedthatwe mentioned bothpositive and negativeaspects. Wecan deducethat all progressalsohas itsdisadvantages. Societyneedsto y needsto progressatthesamepace asscientific and echnological e t chnological advances,butthis isnot alwayseasy. Weare goingto reflecton theadvantagesand disadvantagesof scientific progress.
a) Whathappensto thewater?
WORKSHEET
b) Onceyour wholebodyis inthebath and you sinkto thebottom, doesthe
samethinghappen?
Downloadthisunit’sworksheetanddoactivities16 and17.
Inthesecasesthereisnomathematicalformulatohelpus.Weusea fundamental principleof science:two objectscannotoccupythe samespace.Whenwe submergeanobjectinliquid, thevolumeof theliquid increases. Thevolumeof theobjectweput into theliquid isexactlyequal to theincrease ein in volume.
THINKANDREASON
LABORATORY The Volume ofaStone CLASSROOMLABORATORY
Find someoneinyour classthat usesFacebook. Thenfind another personthat usesa differentsoware, websiteor social network thatneedsthe internetto run. Makea listwiththe namesof thepeopleyou asked and their contributions. Brainstorm:Can you do thethings you do usingthese toolswithout theinternet? How?
CLASSROOM LABORATORY
A. The Positive Contributions ofScience Scienceand technologyhavebrought manybenefits. Here arejust a few of them: Th e yfacilitate con tact betweenpeople.
Thanksto GPS, wecan find anyaddress.
1. Wearegoingtodeterminethevolumeofanirregularobject.Youwillneed: agraduatedcylinder,wateranda marblestone. a) Fill thegraduated cylinder to thehalfwaymark with water. Writedown thelevel of water. b) Putthemarblestoneinto thewater and writedown thenew volume. c) Thedifferencebetweenthetwo volumesisthevolume of th hemarble emarble stone.
ACTIVITIES 4.Convertthe following units: a ) 500 gto kg. b ) 250 cm3 to L. c) 1200 dgto Hg. d) 1960m3 to mL. 5.Calculate the volumeinthe SIunitof asphere witha 10 cm radius.
Experiments to perform in thedesigned classroom. They will teach you how to resolve the theory through practical tasks.
Th e yfacilitate th e se arch forinformation.
or fr Theyare Th eyare veryuseful o ce rtain tasks th anksto their cameras and video recordingfeatures. Theycan cause dependency. T h ey m a ke liveseasier.
our
T h ey m a ke o u r w o r k simpler.
Theyhaveincreased our lifeexpectancy.
EXPERIMENT ScientificAdvances EXPERIMENT
WORKSHEET
Downloadthisunit’sworksheetanddo activity15.
18
4. Scientific advancesare presentin our homes. Find appliancesor devices whichdid notexist in your grandparents’time. Ask your parentsor grandparentsfor information. Takea photo of eachitemand make a data sheet for eachone withthe followinginformation: yearof manufacture, acture, utility, original n al pricewhenit cameonthe marketand currentaverageprice. In groupsof four, preparea poster showingthe mostimportant innovations (discussto decide) and theinformationyou havecollected aboutthem.
ACTIVITIES 16.Name five scientific advances inyourday-to-day life thathave helped you improve yourstandard ofliving. Share yourideas ingroups offour and decide onthe five mostimportantadvances.Brainstorm withthe restof the class tomake ‘The GreatFive’list.
U NI T1 T1
UNIT 1
UNIT 2
2.1. The International International System Onthepreviouspage weaskedyouto inventa newunitof measurement. We gaveyou twoexamples,but therearemanymore. Therefore, therearelotsof differentunits. Butwhichis theidealunit? The InternationalSystemof Units(SI) establisheswhichunit weusefor eachmagnitude.
19
TheSI aimstoprovidea commonreferenceso thatallcountriesusethesame unitforeachmagnitude.Thismeansitis easiertoworktogether.TheSI establishesthefollowingsevenbasicunitss:: Magnitude
EXPERIMENT
Simple demonstrations you can do with material from home. They only take a few minutes to do and have followup exercises.
Unit in th the SI SI
Abbreviation
Length
metre
m
Mass
k ilogram
kg
Time
s econd
Electriccurrent
a mp ere
A
Temperature
Kelvin
K
Amountof substance
mole
mol
Luminousintensity
cand ela
cd
s
2.2. Multiples and Submultiples Submultiples
WORKSHEET
Each unit has complementary activities distributed by headings. Download the worksheets from the
35
IMPORTANT Fundamental magnitudesare thosethatwe can determine directly, withoutneedingtousea secondmagnitude.They allappear inthetable. Derived magnitudesare Derived magnitudesare themagnitude t udes that do notmeetthiscondition. Youwilldiscovertheseas youstudymorephysics cs andchemistry.
WORKSHEET Downloadthisunit’sworksheetanddoactivity9.
Distanceismeasuredinmetresinthe SI. However,aswecan seeinthesetwo cases, itis notalwayshelpfulto measureinthisunit. Insciencewe oftenfind verylargeor verysmallnumbers. Inthesecasesweuse multiples and submultiples of theSIunit. D i a me t er o f a n ovum=0.00014m
Dis t ancefromt n cefromt hecent reoft he Eart ht o t hecent eoft er oft hemoon=384000 000m
ACTIVITIES 12.Indicate whichmultiple or submultiple youwould use in the following examples:the distance betweentwo cities,the mass ofaperson,the lengthof apencil and the size ofan insect.
Online Learning Centre.
UNIT 1
13
VIRTUAL SIMULATIONS
Science 2.0 and others.
SCIENCE2.0
1.2. Mass
B.Scientific Notation
Massisoneof theessential i alpropertiesthata substaancemusthaveto ncemusthavetobe consideredmatter.
Aswell as usingmultiples and submultiples,thereis a mathematical tool that allowsus to writeverylargeo r smallvaluesin a simplerway:scientific notation.
SOLVED EXAMPLES SCIENCE2.0
THINKA ND REASON You canfind exercisesto practiseconverting measurementsof mass and volume at thefollowing link: goo.gl/1fnjNZ.
Throughout the book you can access online virtual simulations of the most important physical and chemical processes. You can also access them from the OLC (Online Learning Centre)..
Scientificnotation isa wayof simplifyingwrittennumbers. Itusespowers of ten.
Wehavea piece of wood, a pieceof metal and a bottlecontainingwater.
These accompany the theory when the maths is more complex.
You canpractise conversionfactorsatthefollowinglink: goo.gl/VSbvdd
a) Do you know whichof thethree hasmore
matter? b) Canwemeasurethisquantity?
SOLVED EXAMPLE
Wecandefinemassinthefollowingway: Mass isa measurementof thequantityof matter anobject has. TheSI unit for massis kilograms(kg). Themass of a substanceis independentof temperature,pressureor location. Forexample e,,anastronautwith haa massof80kg hasthesamemasswhenheis onEarthaswhenheison themoon.Thequantityof i tyofmatteristhesame. To measuremassweuseinstrumentssuchas scales. scales.
2.Express the following numbers inscientific notation: a ) 156 000 000 b ) 0.0025 Solution a ) To expressa largenumber using scientific notation,wedo the following:
WORKSHEET Downloadthisunit’sworksheetanddo activity12.
1. Weonlyputonenumber beforethe decimal point. 2. Theexponentof tenisthe number of placesbetweenthefirstand last numbers.
156 156 000 000 000 = 1.56 · 108
b ) To expressa small number using scientific notation, ion, weuse a similar technique:
1.3. Volume
1. Weonlyput onenumberbeforethe decimal point. 2. Theexponentof tenisthe number of placesbetweenthefirstand last numbers. Theexponentis a negative number.
0.0025 0.0025 = 2.5 · 10-3
Volumeis theotheressential propertya substancemusthaveto a ncemusthaveto beconsideredmatter. Volume isa measurementof howmuchspace anobject occupies. TheSI unitfor volumeiscubic metres(m3). Therefore,anobject witha greatervolumemeansthat itoccupiesmore space. Volumeisindependent of shape. For instance, if wehave1 L of water and distribute itbetweenseveral glasses, westill havethesame amount. Therefore,it occupies thesameamount of space.
a ) 230 hL to L e ) 6 580 gto kg
SOLVED EXAMPLE 1.We normally measure volume inlitres (L),eventhoughthe SI unitis m 3.Do the following conversion:500 cm3 toL. Solution Wehaveto calculatethe equivalency:1 dm3 =1 L 500 cm3 ·
34
ACTIVITIES 13.Change the following units using conversionfactors.Check your answers withapartner.
1 dm3 1L · 0.5 L 1000 cm3 1 dm3 =
c) 5.2 m2 to cm2 g) 470 hm3 to km3
b ) 0.8hto s f ) 3.9cL to daL
d) 56 mgto g h ) 6.25hto min
14.Express the following inSI units using conversionfactors. a ) 7dm b ) 1.2 h c) 3.4cm3
d) 4500 mg
e ) 5600 mm2 f ) 857000 m g) 120 min h ) 3.2 Gg 15.Express the following numbers using scientific notation.Check youranswers witha partner. a ) 9000 m/s
b ) 0.23000 km
c) 623 000 min
d) 0.2350 s
e ) 600 m
f ) 0.0006 h
U NI T2 T2
ACTIVITIES UNIT 1
Exercises to consolidate the theoretical concepts you have learned.
15
End of unit MIND MAP MIND MAP LABORATORY WORK
Download and printtheworksheetyou will find intheOLC to completetheconceptmap of theunit.
Diagram showing the most important concepts in each unit. We invite you complete
Observation
Provinga Hypothesis Units InternationalSystem (SI)
Hypothesis Meas uring
Scientif ic Met hod Experimentation i nvo vl es
d ev el op sstt hr ou gh th e Conclusions
SCIENCE Instruments
u suall yn ynee ds a Laboratory
impacts on on Society
Safetyrules
Advantagesand disadvantages Useof ICT
LevelofEmpathyand CerebralResponse
Thewayour brainrespondsto everythingpositiivethathappens vethathappens to thepeoplea round usdependson our level of empathy. Thisis theconclusion reached bytheresearcher Patricia Lockwoodatthe UniversityCollegeof London (UCL). Specifically, thisinvestigation showshow a partof thebraincalled theanterior cingulatecortex (ACC) seemsparticularlyattuned to good news. Thiscould provethe relevanceof thispartof thebrainin disordersof social behaviour and empathy, includingpsychopathy and autism. To reachthese conclusions, theresearchers scanned thebrains of 30 volunteersaged between19and 32. Theyused magnetic resonanceimagingwhilethe volunteers looked atsymbolsthatpredicted thattheyor other peoplewere goingto winsomemoney. Thestudyfound thattheACC wasactivated inall thevolunteerswhensomebody wasvery closeto winningmoney. However, therewere differencesin theway thispart of hebrain h t ebrain had specialised in itsreactions. Theyseem to berelated to theparticipants’level of empathy. Thepeople whoseACC activationwasmore specialised compared withothers showed aresponse onlywhen other peoplewereclose to winning. However, inother participantsthispart of thebrain activated whenthey themselveswere closeto winning. Thestudy classifiesthese peopleas having littleempathy.
LOOK AROUND YOU
Readings, debates and investigations to encourage reflection and critical thinking.
abc.es/ciencia, 7th October2015
Questions a) Writethe stepsof thescientific method in ther ightorder: results, conclusions, observation, experiment(materials), hypothesis. b) Workinginpairs, matchpartsof thetextwith thesteps of thescientific method. c) Writea questionthat tionthat summarisesthe aimof theresearch. Thenanswer thequestions. d) Canyou think of apossibleapplicationfor this research? Brainstormasa wholeclass.
24
Introduction Wehavedifferent typesof sponges. Wewantto findoutwhich typeabsorbs thelargest amountof water. To do this, wewill use thescientific method. Material • Sponges • B e ak e r
• W at e r • Crucible
Task 1. Describethe characteristicsyou observein eachsponge. Elaboratea hypothesison whichtype of spongeabsorbsmore water basedonyour observations. 2. Measuretheamountof water eachspongehas absorbed. Subtracttheinitial massof thedry spongefrom thefinal massof thewetsponge. Do h thisfor isfor eachsponge. 3. A useful wayof identifyingwhichsponge ismore effectiveisfinding outthe absorptioncapacity per gram. To do this, dividethemassof the absorbed water bythemassof the sponge. Compare thesevalues and deducewhichsponge ismore absorbent. 4. Reflect onthe data youobtained. Wasyour hypothesistrue? 5. Download and printtheworksheet‘Scientific Method Poster’. Makea poster to show theresults of your experiment.
U NI T1 T1
UNIT 1
25
FINAL ACTIVITIES
FINALACTIVITIES
Bread A baker makes bread bymixing flour, water, saltand yeast. Wheneverything ismixed, he placesthe doughin a contaainer iner for several hoursfor theprocess of fermentationto ationto occur. Duringfermentation, a chemical change occursinthe dough:theyeast(a single-celled fungus) transformsthestarchand sugar of the flour into carbondioxideand alcohol.
Themassofthedoughisthesameasat the beginningof eachoneof thefourexperiments shown.Whichtwoexperimentsshouldthebakercomparetodetermineiftheyeastis responsibleforthelossof mass? a ) Experiments
b ) Experiments
1 and 2. Experiments 2 and 4.
d) Experiments
c)
Question 1
Fermentationmakesthemix ionmakesthemix rise. Whydoesit rise? msinto sinto a) Itproducesalcohol,which transform gas. b) Itproducesagas, carbondioxide.
Thesingle-celledfungireproduceinside.
d) Thefermentatiiontransformstheliquidwaontransformstheliquidwa-
terintovapour. Question 2
A few hoursafter makingthedough,thebaker weighsit and observesthatitsmasshas decreased.
1 and 3. 3 and 4.
Question 3
Inthe dough,the yeasttransformsthestarch andsugarsofthe flourintocarbondioxideand alcoholthroughachemicalreaction.Wheredo thecarbonatomsthatmake upthe carbondioxideandalcoholcomefrom?Answer yes or no foreachoneof thepossibleexplanatiions. ons. a ) Somecarbonatomscomefromthesugars. b ) Somecarbonatoms werepart of thesalt molecules. c) Somecarbonatomscomefromthe water. d) Thecarbonatomsformed fromother elementsina chemicalreaction.
USE YOUR SKILLS
BasicActivities 1.
One PISA-type activity and one task per unit to put your knowledge, skills and abilities to the test.
2.
Indicate which of the following are simple substances and which are compounds: oxygen, ammonia, ozone, mercury, 96% alcohol, oil, plastic, a lump of coal, and pipe. Compare yourclassificationwithapartner. Matterhaselectricalproperties:
6.
19 and A = 39.Calculatehowmanyprotons,neutronsand electronsithas.
a) Because it contains electrically charged
particles. b) Becauseit containselectrons. c) Becauseit containsprotons. d) It does not have electrical properties, be-
8.
causeitdoesnotcontainchargedparticles. 3.
Choosethecorrectdefinitionofanatom:
a) A positive sphere with negative charges
a) Atoms of the same element with different
numbersofelectrons. b) Atoms of the same element with different
encrustedin it. c) A positive nucleus with negative charges revolvingaround it. d) A negative nucleus with positive charges revolvingaround it.
5.
Research as a small group about ‘quarks’. Wherecantheybefound? Indicate which of the following contain atoms: aspark,a bacterium,a pieceofwood,a flower, anecho, raindropsand a hair fromyour head.
Lid Container
Flour, water, salt withy ea st
Flour, water, salt withoutyeast
Whenthe ripe (fermented) bread dough is baked intheoven, thebubblesof gasand vapour ni thedough dilate. Whydo thegases and vapours dilatewhentheyareheated?
numbersofprotons. c) Atoms of the same element with different
numbersofneutrons. d) Atoms of the same element with different
numbersofthesethreeparticles. 10.
11.
12.
Explain the difference between natural and artificial isotopes. Work with a partner to search the internet for information on three artificial isotopes used in medicineandcommentontheir applications. Choosethecorrectdefinitionof anion: a) Atomswhichhavegainedorlost electrons. b) Atomswhichhavegainedorlostprotons.
a ) Theirmoleculesgetbigger.
E p xe ir me nt 2
The element copper (Cu) has Z = 29 and 30 neutrons. Calculate how many protons and electrons it has. Calculate its atomic number (A). Compare your answers to 6, 7 and 8 with a partner.
9. Choosethecorrectdefinitionofanisotope:
encrustedin it. b) A negative sphere with positive charges
4.
If a neutral atom has 16 protons and 16 neutrons, how many electrons does it have? What is its atomic number? What is its mass number?
7. The element potassium (K) has Z =
Question 4 Lid Container
E xpe ir me nt 1
With related tasks.
2. Fill thecruciblewith water. Putthe firstspongein it. Aswe need to eliminateall theair fromthe sponge, squeezeit several times. Leavethe spongein thecrucible for oneminute. 3. Removethe spongeand hold itup so theexcess water dripsout. Hold thesponge asgently as possibleso itretains asmuch water aspossible. 4. Putthe spongesoaked inwater inthe beaker and measurethe mass. 5. Put thedata ina table.Repeatthemeasurement several timesand calculatetheaverage mass. 6. Repeattheprocess witheach sponge.
USE YOUR SKILLS
c)
LABORATORY WORK
• Sc al e s • Procedure
Procedure Work ingroupsof threeor four. 1. Measurethe massof thebeaker andof hedifferent h t edifferent sponges.
LOOKAROUND YOU
themyou with other concepts have studied.
Objective Usingthe scientific method to solvea problem.
c) Atomswhichhavegainedorlost neutrons.
b ) Their moleculesmovefaster.
E xpe ir me nt 3
1 28
Open container
Open container
Flour, water, salt withy ea st
Flour, water, salt withoutyeast E p xe ir me nt 4
c)
Thenumberof moleculesincreases.
Check your answersto these questionswith your partner. Explainyour choiceif itis differentandlistentohis/herexplanation.Then,decidewhichoneis correct.
U NI T5
100
U N TI 4
OLC STUDENT
Remember, throughout the unit we recommend you visit the OLC and download the worksheets associated with the content of each unit. www.mheducation.es
13.
Challengea partneronthefollowingelements represented by their symbols. Which one is differentfromitsEnglishname?N,Ne, He,Cu, Niand Pt.
14.
If you have a substance which is a good conductor of electricity in its solid state, is it a metal or a non-metal?
d) Theirmoleculescollideless frequently
Separated into basic, consolidation and advanced activities so you can reach the required level of knowledge.
TABLE OF CONTENTS
UNIT – – – – – – – – –– – – – – – – –– – – – – – – –– – – – – – – – –– – – – – – – –– – – – – – – – –– – – – – – – –– – – – – – – –– – – – – – – – –– – – – – – – –– – – 1. Introductionn to the Scientific Method ........................... Introductio ............................ ............................ ............................ ............................ ............................ ........................... ............. Scientific Activity 2. Magnitudes..................................... ............................ ............................. ............................. ............................ ............................ ............................ ............................ ............................ ........................... ............. 3. The Laboratory ........................... ............................ ............................ ............................ ............................. ............................. ............................ ............................ ............................ ............................ ............... 4. Science in Society.................................... ............................ ............................ ............................. ............................. ............................ ............................ ............................ ............................ ............... 5. Your First Research Project ............................ ............................ ............................ ............................ ............................. ............................. ............................ ............................ .................... Mind Map ................ ........................... ............................ ............................. ............................. ............................ ............................ ............................ ............................ ............................ ............................. ............................. .................... .... Look around You ............. ........................... ............................ ............................ ............................ ............................. ............................. ............................ ............................ ............................ ............................ ...................... ........ Laboratory Work .............. ............................ ............................ ............................. ............................. ............................ ............................ ............................ ............................ ............................. ............................. .................... .... Final Activities ............... ............................. ............................ ............................ ............................ ............................ ............................ ............................. ............................. ............................ ............................ ........................ .......... Use Your Skills ................. ............................ ............................ ............................ ............................ ............................. ............................. ............................ ............................ ............................ ............................ ...................... ........ UNIT – – – – – – – – –– – – – – – – –– – – – – – – –– – – – – – – – –– – – – – – – –– – – – – – – – –– – – – – – – –– – – – – – – –– – – – – – – – –– – – – – – – –– – – 1. Matter and Its Properties............ Propertie s.......................... ............................ ............................ ............................ ............................ ............................ ............................. ............................. ........................ .......... The Properties 2. Density ............... .............. . ............. .............. . ............. .............. . ............. .............. . ............. .............. . ............. ............... . .............. .............. . ............. .............. . ............. .............. . ............. .............. . ............. .............. . ............. . of Matter 3. States of Aggregation ........................... ............................ ............................. ............................. ............................ ............................ ............................ ............................ ............................. ............... 4. The Kinetic Theory Theor y of Matter........................... ............................ ............................. ............................. ............................ ............................ ............................ ............................ ............... 5. The Gas Laws ....................... ............................ ............................ ............................. ............................. ............................ ............................ ............................ ............................ ............................ ...................... ........ Mind Map ....................... ............................ ............................. ............................. ............................ ............................ ............................ ............................ ............................ ............................. ............................. .......................... ............ Look around You ............... ........................... ............................ ............................. ............................. ............................ ............................ ............................ ............................ ............................ ............................. ..................... .... Laboratory Work .............. ............................ ............................ ............................. ............................. ............................ ............................ ............................ ............................ ............................. ............................. .................... .... Final Activities ............... ............................. ............................ ............................ ............................ ............................ ............................ ............................. ............................. ............................ ............................ ........................ .......... Use Your Skills ................. ............................ ............................ ............................ ............................ ............................. ............................. ............................ ............................ ............................ ............................ ...................... ........ Research Project I – – – – – – – – –– – – – – – – –– – – – – – – – –– – – – – – – –– – – – – – – –– – – – – – – – –– – – – – – – –– – – – – – – –– – – – – – – – –– – – – – – – –– – – 1st stage: Identifying the Problem ............................ ............................ ............................. ............................. ............................ ............................ ............................ ............................ ............... Playing with Density 2nd stage: Formulating the Hypothesis..................... ............................ ............................ ............................ ............................ ............................ ............................. ........................... ............ 3rd stage: Research Resea rch ........................... ............................ ............................ ............................ ............................ ............................ ............................. ............................. ............................ ............................ .................... 4th stage: Materials and Methods ............................ ............................ ............................. ............................. ............................ ............................ ............................ ............................ ............... 5th stage: Conclusion Conclusio n ........................... ............................. ............................. ............................ ............................ ............................ ............................ ............................ ............................. ........................... ............ UNIT – – – – – – – – –– – – – – – – –– – – – – – – –– – – – – – – – –– – – – – – – –– – – – – – – – –– – – – – – – –– – – – – – – –– – – – – – – – –– – – – – – – –– – – 1. Classifying Classifyi ng Matter ............................ ............................ ............................ ............................ ............................ ............................. ............................. ............................ ............................ ...................... ........ Matter Systems 2. Solutionss ............................ Solution ............................ ............................ ............................. ............................. ............................ ............................ ............................ ............................ ............................ ........................... ............. 3. Types of Solutions ................ ............................ ............................ ............................. ............................. ............................ ............................ ............................ ............................ ............................ ..................... ..... 4. Concentra Concentration tion of Solutions ............................. ............................ ............................ ............................ ............................ ............................ ............................. ............................. .................... 5. Techniques for Separating Separatin g Mixtures ........................... ............................ ............................. ............................. ............................ ............................ ............................ ............... Mind Map .............. ............................ ............................ ............................ ............................ ............................ ............................. ............................. ............................ ............................ ............................ ............................ ...................... ........ Look around You ............. ........................... ............................ ............................ ............................ ............................ ............................. ............................. ............................ ............................ ............................ ...................... ........ Laboratory Work .............. ............................ ............................ ............................ ............................. ............................. ............................ ............................ ............................ ............................ ............................. ..................... .... Final Activities .............. ............................. ............................. ............................ ............................ ............................ ............................ ............................ ............................. ............................. ............................ ........................ .......... Use Your Skills ................. ............................ ............................ ............................ ............................ ............................ ............................. ............................. ............................ ............................ ............................ ...................... ........ UNIT – – – – – – – – –– – – – – – – –– – – – – – – –– – – – – – – – –– – – – – – – –– – – – – – – – –– – – – – – – –– – – – – – – –– – – – – – – – –– – – – – – – –– – – 1. Pure Substances: Substances : Simple and Compound Substances ........................... ............................. ............................ ............................ ...................... ........ The Structure 2. Atoms and Subatomic Particles Particles.............. .............. .............. . ............. .............. . ............. .............. . ............. .............. . ............. .............. . ............. ............... . .............. .............. . ............. .......... . ......... of Matter 3. Atomic Models Mode ls ............................ ............................ ............................ ............................ ............................ ............................. ............................. ............................ ............................ ............................ ............... 4. Atomic and Mass Numbers ............................. ............................ ............................ ............................ ............................ ............................ ............................. ............................. .................... 5. Introductio Introductionn to the Periodic System System ........................... ............................ ............................. ............................. ............................ ............................ ............................ ............... 6. Chemica Chemicall Bonds: Molecules and Crystals ............................ ............................ ............................ ............................. ............................. ............................ .................... Mind Map .................. ............................. ............................. ............................ ............................ ............................ ............................ ............................ ............................. ............................. ............................ ............................ .................... Look around You ............. ........................... ............................ ............................ ............................ ............................ ............................. ............................. ............................ ............................ ............................ ...................... ........ Laboratory Work .............. ............................ ............................ ............................ ............................. ............................. ............................ ............................ ............................ ............................ ............................. ..................... .... Final Activities ............................. ............................. ............................ ............................ ............................ ............................ ............................ ............................. ............................. ............................ ........................ .......... Use Your Skills ............................ ............................. ............................. ............................ ............................ ............................ ............................ ............................. ............................. ............................ ........................ ..........
UNIT 5
6 8 12 16 18 22 24 24 25 26 28 30 32 36 38 40 46 50 50 51 52 54 56 56 56 56 57 57 58 60 64 66 70 72 74 74 75 76 78 80 82 83 86 88 92 94 98 98 99 100 102
Chemical Reactions
1. Changes in Matter M atter ............................. ............................ ............................ ............................ ............................ ............................. ............................. ............................ ............................ ..................... ..... 2. Chemicall Re Chemica Reactions actions ........................... ............................ ............................ ............................ ............................ ............................. ............................. ............................ ............................ ..................... ..... 3. Law of Conservation Conser vation of Mass ........................... ............................ ............................ ............................ ............................ ............................. ............................. ............................ ............... 4. Energy in Reactions Reacti ons ........................... ............................ ............................ ............................ ............................. ............................. ............................ ............................ ............................ ..................... ..... 5. Reaction Rate ........................... ............................ ............................ ............................. ............................. ............................ ............................ ............................ ............................ ............................ ................... ... 6. Importa Important nt Chemical Reactions ............................. ............................. ............................ ............................ ............................ ............................ ............................ ......................... ........... 7. Chemistryy in Our Lives ........................... Chemistr ............................ ............................ ............................. ............................. ............................ ............................ ............................ ........................... ............. 8. Chemistr Chemistryy and the Environment Envi ronment ............................ ............................ ............................ ............................ ............................. ............................. ............................ ...................... ........ Mind Map. .................................... ............................ ............................ ............................ ............................. ............................. ............................ ............................ ............................ ............................ ........................... ............. Look around You ............................. ............................ ............................ ............................ ............................ ............................. ............................. ............................ ............................ ............................ ..................... ..... Laboratory Work ............................ ............................ ............................ ............................ ............................ ............................. ............................. ............................ ............................ ............................ ..................... ..... Final Activities ............................... ............................. ............................ ............................ ............................ ............................ ............................. ............................. ............................ ............................ ...................... ........ Use Your Skills ...................................... ............................. ............................ ............................ ............................ ............................ ............................ ............................. ............................. ............................ ...............
UNIT ––––––––––––––––––– ––––––––––––––––––––– ––––––––––––––––––––– –––––––––––––––––––––– –––– 1. Kinematicss ................................. Kinematic ............................ ............................. ............................. ............................ ............................ ............................ ............................ ............................ ............................. ..................... Forces and Movement 2. The Concept Con cept of Force ............................. ............................ ............................ ............................. ............................. ............................ ............................ ............................ ........................... ............. 3. Friction ............................ ............................. ............................. ............................ ............................ ............................ ............................ ............................ ............................. ............................. ............................ ............... 4. The Force of Gravity Gravit y .................. ............................ ............................ ............................ ............................. ............................. ............................ ............................ ............................ ........................... ............. 5. Electric Force ......................... ............................ ............................ ............................ ............................. ............................. ............................ ............................ ............................ ............................ ..................... ..... 6. Magnetic Force ................................. ............................ ............................ ............................ ............................ ............................. ............................. ............................ ............................ ...................... ........ 7. Electricity Electrici ty and Magnetism ............................ ............................ ............................ ............................. ............................. ............................ ............................ ............................ ..................... ..... Mind Map. .................................. ............................. ............................ ............................ ............................ ............................ ............................ ............................. ............................. ............................ ............................ ............... Look around You .......................... ............................. ............................. ............................ ............................ ............................ ............................ ............................. ............................. ............................ ...................... ........ Laboratory Work .............................. ............................ ............................. ............................. ............................ ............................ ............................ ............................ ............................ ............................. ..................... Final Activities. ................................ ............................ ............................ ............................ ............................. ............................. ............................ ............................ ............................ ............................ ..................... ..... Use Your Skills ........................................ ............................ ............................ ............................ ............................. ............................. ............................ ............................ ............................ ........................... ............. Research – – – – – – – – –Project – – – – – –II– – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – –
130 132 138 143 144 148 150 151 152 152 153 154 156
1st stage: Identifying Identify ing the Problem ..................... ............................ ............................ ............................ ............................ ............................. ............................. ............................ ...................... ........ 2nd stage: Formulating the Hypothesis.............................. ............................ ............................ ............................ ............................ ............................ ............................. ..................... 3rd stage: st age: Research ..................... ............................. ............................. ............................ ............................ ............................ ............................ ............................. ............................. ............................ ...................... ........ 4th stage: Materials Mater ials and Methods Metho ds ............................ ............................ ............................ ............................ ............................ ............................. ............................. ............................ ............... 5th stage: sta ge: Conclusion Co nclusion ...................... ............................ ............................. ............................. ............................ ............................ ............................ ............................ ............................ ............................. .....................
158 158 158 158 159 159
UNIT ––––––––––––––––––– ––––––––––––––––––––– ––––––––––––––––––––– –––––––––––––––––––––– –––– 1. Energy ........................... ............................ ............................ ............................. ............................. ............................ ............................ ............................ ............................ ............................ ............................. ..................... Energy 2. Energy, Heat and Temperature Temperatu re ............................ ............................. ............................ ............................ ............................ ............................ ............................ ......................... ........... 3. Thermal Expansion ...................................... ............................. ............................ ............................ ............................ ............................ ............................ ............................. ......................... .......... 4. Energy in Our Lives .................... ............................ ............................. ............................. ............................ ............................ ............................ ............................ ............................ ........................... ............. 5. The Need for Energy Saving S aving ................ ............................. ............................. ............................ ............................ ............................ ............................ ............................ ........................... ............. Mind Map ............................ ............................. ............................ ............................ ............................ ............................ ............................. ............................. ............................ ............................ ............................ ...................... ........ Look around You ........................... ............................. ............................ ............................ ............................ ............................ ............................. ............................. ............................ ............................ ...................... ........ Laboratory Work ................... ............................. ............................ ............................ ............................ ............................ ............................ ............................. ............................. ............................ ............................ ...............
160 162 166 170 172 178 180 180 181
Final Activities .................. .............. .............. .............. .............. .............. .............. ............... ............... .............. .............. .............. .............. .............. .............. .............. .............. .............. .............. .............. .............. ....... ..... Use Your Skills ............... ........................... .............. .............. .............. ............... ............... .............. .............. .............. .............. .............. .............. .............. .............. .............. .............. .............. .............. ............... ............... .......... ..........
182 184
UNIT – – – – – – – –– – – – – – – – –– – – – – – – –– – – – – – – – –– – – – – – – –– – – – – – – –– – – – – – – – –– – – – – – – –– – – – – – – –– – – – – – – – –– – – 1. Electric Current .................................... ............................. ............................. ............................ ............................ ............................ ............................ ............................ ............................ ................... ... Electric Current 2. Electrical Electric al Magnitudes M agnitudes ............................ ............................. ............................ ............................ ............................ ............................ ............................ ............................. ............................. ............... 3. Electric Circuits .................. ............................. ............................. ............................ ............................ ............................ ............................ ............................. ............................. ............................ ...................... ........ 4. Electrical Machines.............. Machines............................ ............................ ............................ ............................ ............................ ............................. ............................. ............................ ............................ ..................... ..... 5. How is the Electrical Energy in Our Homes Produced? ............................ ............................ ............................ ............................ ................... ... 6. The Electronic Electroni c Revolution Revolu tion ................................. ............................ ............................ ............................ ............................ ............................. ............................. ............................ ............... Mind Map ........................... ............................ ............................. ............................. ............................ ............................ ............................ ............................ ............................. ............................. ............................ ...................... ........ Look around You............... ............................. ............................ ............................ ............................ ............................ ............................ ............................. ............................. ............................ ............................ ..................... ..... Laboratory Work ............................ ............................ ............................ ............................ ............................ ............................ ............................. ............................. ............................ ............................ ..................... ..... Final Activities ............................ ............................ ............................ ............................. ............................. ............................ ............................ ............................ ............................ ............................ ......................... ........... Use Your Skills ............................ ............................ ............................ ............................ ............................. ............................. ............................ ............................ ............................ ............................ ......................... ...........
186 188 189 192 198 199 204 206 206 207 208 210
Two Experiments Which Changed the World
Annex
104 106 108 110 112 114 116 118 120 124 124 125 126 128
Chemical Formulation Formulatio n ............................ ............................ ............................ ............................. ............................. ............................ ............................ ............................ ............................ ......................... ........... 212
ENERGY
WORK WITH THE TEXT
Download and print the worksheet Work with the Text . Answer the following questions about the text: 1. Name the three d discoveries iscoveries that hav have e changed how w we e liv live. e. 2. What did humans use fire for in prehi prehistory? story? 3. Do you know how a steam machine works works?? T Try ry to explain it. 4. Working with yyour our partner partner,, explain the me meaning aning of 'renewable energy source’ and give an example.
CHALLENGE The batteries in our mobile phones accumulate energy and transform it into light, sound, waves, images and colour. Turn off your mobile and take out the battery. Find the battery capacity (for example, 2600 mAh) and the nominal voltage (for example, 3.8 V). Write down the values and do the following calculation: Battery energy (J) = battery capacity (mAh) · 3.6 · voltage (V). (V ). J in this equation stands for joules, the unit we use to measure energy. Now discuss with your partner: • Which one of you has the best battery? • How much energy (in joules) do your batterie batteriess still have? • Why do yyour our mobile batterie batteriess run down down?? • Look at your your percentages. W Which hich systems on your mobile mobiless consume the most energy? • Suggest ideas about how to red reduce uce this percentage.
KEYWORDS
Download and print the activities that will guide you through the essential vocabulary of this unit.
FIND A CLAS CLASSMATE SMATE
Download and print the worksheet ‘Find a Classmate: Energy Sources’. Share experiences about this topic with your classmates and discover interesting inter esting things about them.
Energy
DID YOU KNOW?
When we heat a sheet of steel, part of its en-
Physics and chemistry are sciences that study the behaviour of matter. Anything that happens to a material object implies a change in this object or its environment. Science has a very powerful tool to study these changes: energy.
ergy becomes luminous radiation. At a low temperature it is red, but it can become white or even blue as the temperature increases. The same phenomenon occurs with stars: we can know their temperature according to the colour we see.
WORKSHEET
Download this unit's worksheet and do activity 1.
THINK AND REASON Which of these systems has a greater capacity to produce a change in its surroundings? What types of changes can they produce? • A red-hot sheet of steel or the same sheet at room temperature. • A car travelling travelling at 100 km/h or the same car trav travelling elling at 60 km/h. • A kilogram of coal or a kilogram of wood. Scientists analyse the changes that occur in nature. To predict these changes, they defined a magnitude called energy. energy. It is one of the most important magnitudes in science. Energy is the magnitude which quantifies the capacity of an object to proEnergy is duce changes. These changes can be within itself or in its environment. As you learned in the unit on scientific activity, a magnitude is any property of a system that we can measure. This means we can give it a numerical value and a unit. The unit unit of of energy in the International System is the joule the joule (J). Other units of energy are the calorie (cal), the kilowatt hour (kWh) and the tonne of oil equivalent (toe). 1 cal = 4.19 J
1 kWh = 3.6 · 106 J
1 toe = 4.19 · 1019 J
ACTIVITIES 1. What type of changes can a litre of petrol, a car travelling at 80 km/h and a mobile battery produce? Assign the following quantities of energy to each one: 3.5 · 104 J, 3.5 · 107 J, 3.5 · 10 5 J. 2. Interpret the graph using the definition of energy given above. Comment on your results with your partner. 3. What needs more batteries: a talking doll or a doll that talks and crawls?
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Mobile battery
45000 ) J ( y g r e n e d e t a l u m u c c A
40000 35000 30000 25000
Musical toy battery
20000 15000 10000 5000
Watch battery
0
U NIT 7
1.1.. Types of Energy 1.1 Objects can produce changes in many ways. Scientists group these properties into different types of energy. Observing a family in their country home, we find many types of energy.
Potential energy measures
The light The light and sound sound emitted emitted by the
Kinetic energy measures the capacity of an object to produce changes depending on its mass and its velocity. This plane has a very large amount of kinetic energy.
the capacity of an object to produce changes depending on its mass and the height at which it is positioned.
television are two forms of energy energy called electromagnetic called electromagnetic energy and and sound energy.
Electrical energy energy is associated with electric currents.
Chemical energy measures the capacity of different types of substances to produce changes. The wood is burning and this is how it releases its chemical energy.
Thermal energy energy measures the capacity of a system to produce changes depending on its mass and its temperature.
1.2. 1. 2. The Prope Properties rties of Ener Energy gy An object has a specific amount of energy depending on its velocity velocity,, height height,, temperature and temperature and molecular properties. properties. This amount of energy can:
ENERGY 2.0
• Transform into Transform into another type of energy that still belongs to the same object. For example, a television transforms electrical energy into electromagnetic energy.
Go to the following link: goo.gl/xd7uoE Combine different elements to see how energy is transformed, transfers and dissipates, but it is always conserved.
• Transfer to another object in the same form or in a different form. For example, the chemical energy of burning wood transforms into thermal energy. This thermal energy is then transferred to the receptacle on the fire. • Dissipate. This means that the energy is transferred to the air, to water or to the ground. It is divided among these molecules, sothe thefire energy becomes useless. For example, part of theall thermal energy from dissipate dissipates s into the surrounding air. The most important thing to remember about energy is:
WORKSHEET Energy is always conserved. It cannot be created or destroyed. Any process always obeys the following rule: Initial energy = Transformed energy + Transferred energy + Dissipated energy
Download this unit’s work sheet and do activities 2 sheet and 3.
UNIT 7
WORKSHEET
Energy is conserved and this is its main property. If we know the energy an object has, we can calculate the magnitude of changes this object can produce. This is very useful for science and technology. Here are two examples to help you understand the properties of energy.
Download this unit's worksheet and do activities activities 4, 5 and 6. All the petrol’s energy is energy is used in other forms or it dissipates. The energy is conserved, so the two columns have the same height.
60% of the energy dissipates as 60% thermal energy into energy into the air and the ground or as sound energy, energy, making the noise of the engine, etc.
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) s e l u o j f o s n o i l l i m ( y g r e n E
2000 1800 1600 1400 1200 1000 800 600 400 200 0 Chemical energy contained in 50 litres of petrol
40% of the energy transforms into kinetic 40% kinetic,, electromagnetic (lights) electromagnetic (lights),, sound (radio) (radio) and thermal (heating) energy. energy. This is the energy which makes the vehicle work.
Energy consumed
The two columns are the same height. This indicates that the energy is conserved. conserved. Part of the energy of the gas is used to heat the th e water and pasta. However, part of it dissipates, increasing the temperature of the air and becoming useless.
6.00E+02 5.00E+02 4.00E+02 3.00E+02
2.00E+02 1.00E+02 0.00E+02 Chemical energy contained in the gas
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Energy consumed during cooking
U NIT 7
CLASSROOM LABORATORY
Different Types of Energy
1. Any laboratory experiment produces changes and therefore involves different types of energy. For the following experiment you will need: a system to heat water (hotplate, Bunsen burner, etc.), a saucepan, water, a funnel and a paper windmill. (You can find instructions on how to make the paper windmill at goo.gl/nbceeW goo.gl/nbceeW.) .) Put the water in the saucepan and bring it to the boil. Carefully hold the funnel upside down (with the wide part at the bottom) over the steam. Put the windmill above the narrow part of the funnel, where steam should be coming out.
• Green shows the energy that dissipates into the air during the cooking process. • Red shows the t he thermal energy the pasta gains as its temperature increases. • Yellow shows the thermal energy the water gains as its temperature increases.
• What happens to the windmill? windmill? • Indicate all the energy transformations transformations and transfer transferences ences that oc oc-cur in this experiment. Is energy dissipating in any way? • If we turn off the heat, the windmill will eventu eventually ally stop spinning. Explain why using the concept of energy conservation.
EXPERIMENT 1. Look for a semi-spherical object at home, such as a salad bowl, cereal bowl, etc. Put a marble on the top part and let it ffall all into the receptacle. • What type of energy energy does the marble have have when you let it rrest est on the top part of your semi-spherical object? What type of energy does it have when it finally stops? Is there conservation of energy?
ACTIVITIES 4. Create a poster similar to the compositions in section 1.2 1.2.. Find three images on the internet and describe the energy transformations linked to each image. Make sure you use examples involving the transformation, transference, dissipation and conservation of energy. 5. Working with your partner, describe the energy transformations that take place in the following situations:
The energy captured by a solar panel transforms into the energy transmitted by a television.
The electrical energy that heats a ceramic hob results in a cooked potato.
The sun’s electromagnetic energy results in a sack of flour.
The energy from a sack of flour results in a person running in the park.
6. Laura is four years old and has a toy phone with batteries. The keys light up and make sounds when pressed. Laura does not understand u nderstand why her father says that the batteries will run out. Can you explain why?
UNIT 7
ENERGY 2.0
To understand the concepts of temperature and thermal energy, watch the simulation at goo.gl/qm4h1r When microwaves transfer thermal energy to the molecules, they increase
Energy, Heat and Temperature
In the unit on the properties of matter, you learned that the temperature of an object is a consequence of the average speed of its particles. These particles can produce changes because of their speed. Therefore, they have a type of energy called kinetic called kinetic energy. The temperature of an object is a property which measures the average kinetic energy of the particles in the object. The capacity of objects to produce changes because of their temperature and their mass is called thermal energy. Therefore, thermal energy is a macroscopic term to measure the kinetic energy of the enormous number of particles in
165
the kinetic energy of the molecules. Therefore, the temperature of the water also rises.
WORKSHEET
unit ’s workDownload this unit’s
an object. The higher the temperature of an object, the more kinetic energy its particles have. The greater the mass of an object, the more particles it has. Therefore, the higher the temperature and the greater the mass, the more thermal energy an object has. Heat is the term used in physics to group all the ways of transferring thermal energy between objects. Objects have thermal energy and this transfers to other objects as heat. This transference always goes from the ob ject with the highe higherr tempe temperature rature to th the e object with th the e low lower er tempe temperature rature..
sheet and do activities 7 and 8.
low temperature
high temperature Mass: 5 kg Temperature: 150 °C Thermal energy: 950 J HEAT
Mass: 10 kg Temperature: 60 °C Thermal energy: energy: 1500 1 500 J
ACTIVITIES 7. Which has more thermal energy: a bucket with 20 litres of water at 60 °C or a glass full of water at 80 °C? What experiment could you do to prove this? Is there a transfer of energy as heat in this experiment? Share your results with your partner. 8. Imagine we put the water from the two receptacles in Activity 7 together. Would the energy transfer as heat from the water at 60 °C to the water at 80 °C or vice versa versa? ?
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9. Sparklers burn at temperatures of over 1000 °C. Working in pairs, apply the ideas from Activity 7 to explain why the small sparks from a sparkler are not dangerous. 10. Compare the normal meaning of the word ‘hot’ with the scientific meaning based on the following phrases: 'I'm so hot!' and 'The soup is very hot.' Write them in a way that is scientifically correct. Compare your sentences with the rest of the class class..
U NIT 7
2.1.. Ways of Transferring Thermal 2.1 Energy There are three ways an object can transfer thermal energy to another object:
CONDUCTION
CONVECTION
Conduction is the transference Conduction of thermal energy between two objects as a result of collisions between their particles. In these col-
Convection is the transference of thermal energy linked to Convection the movement of matter. It occurs in liquids and gases. These are the states of matter which can flow.
lisions, the particles of the object with a higher temperature transfer part of their energy to the object
The air in contact with a radiator increases its temperature by conduction. As the air temperature increases, its density decreases and the now hot air rises. Cold air is denser, so it descends and comes into contact with the radiator, increasing
with a lower temperature. It is the same as when two balls collide: the faster ball increases the speed of the slower ball.
its temperature. This is how all the air in the room heats up.
Your hand or the air heat up by conduction when they are in contact with the radiator. Energy transfers from the area with a higher temperature to the area with a lower temperature.
If two objects are in contact for enough time, their temperature ends up being the same. The transfer of energy through particle collision then stops because their particles have the same amount of energy. At this point we say the ob jects have reached thermal equilibrium. The redistribution of energy by con-
RADIATION
duction depends the characteristics of the colliding collidinon g particles.
Radiation Radiation is is the transferen transference ce is ofthe thermal energy through tromagnetic waves. Radiation only mechanism whicheleccan occur in a vacuum. In other words, where there is an absence of matter. All objects emit energy by radiation. The higher their temperature, the more energy they emit.
• Materials such as metal are good at transferring heat. They are called thermal conductors. conductors. • Materials such as plastic plastic are no nott good at transferring heat. They are called insulators insulators..
The particles in the metal of the radiator are very hot, so they vibrate with a lot of energy. They emit part of this energy in the form of waves. These waves transfer the energy to any other object they come into contact with.
UNIT 7
Conduction, convection and radiation are present everywhere in our daily lives. Here are some examples.
The energy from the sun reaches Earth by radiation.. In other words, in the form of radiation electromagnetic waves. Remember that there is no matter in space. Therefore, this is the only possible way this energy can be transferred. The water vapour that evaporates from the sea rises by convection convection.. When it reaches a certain height, the temperature is much lower. The water then condenses to form clouds.
Air is an excellent thermal insulator. That is why double-glazed windows are very effective. The
When we swim in the sea, we notice that the deeper water is colder. Cold water has a higher density, so it sinks downwards. The surface water receives the sun’s energy and warms up. Because it is less dense, it
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stays at the top.
two panes of glass have to be close together to stop convection currents from forming. Convection currents transfer thermal energy from one place to another.
Wind is the movement of air. The main factor in wind is convection convection currents. Hot air rises and a cold mass of air takes it place, producing wind.
WORKSHEET
Download this unit’s unit ’s worksheet and do activities 9 and 10.
In tall buildings, the higher flats are warmer than the lower flats because of convection convection currents.
Plastic is a thermal insulator. The plastic handle stops the thermal energy from the pan reaching your hand. Modern houses have thermal insulating material inside their walls. This stops heat being transferred from inside to outside the house through conduction conduction.. Old houses did not have this material, but they had thicker walls. This made the exchange of o f heat diffi di fficult.
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They are frying vegetables in this kitchen. The pan is metal, an excellent thermal conductor. This allows the thermal energy from the flame to reach the vegetables by conduction conduction..
U NIT 7
2.2. 2. 2. isEnergy Transfer by Sound Sound is Sound a form of energy transference through sound waves. In contrast to electromagnetic waves, sound waves cannot travel in a vacuum. This is because their energy is propagated through the vibrations of physical matter.
WORKSHEET
A good example is a guitar string or the membrane of a drum, where kinetic energy transforms into sound energy.
Before experiment 3, download this unit’s worksheet and do activity 11.
EXPERIMENT How do you wrap up warm? 2. Wrap one ice cube in aluminium foil and another one in a jumper. Wait 45 minutes, then unwrap the ice cubes and observe what has happened. Which material is a better thermal conductor: the aluminium foil or the fabric?
A pupil makes this comment: ‘Jumpers keep us warm in winter, but this one kept the ice cube cold.’ Explain this apparent contradiction to the student.
Dancing ink 3. We are going to observe the phenomenon of convection using hot and cold water. You will need: water, ink or colorant for the water, a small glass jar (a jam or pepper jar, for instance), and a large glass jar or a plastic bottle. b ottle. Make a hole in the lid of the small jar (using a screwdriver and a hammer, for example). Fill the large jar or bottle with cold water with no colorant. Now fill the small jar with colour-
ed hot water and put it inside the large receptacle filled with clear cold water. What happens to the hot water in the small jar? Explain this behaviour behaviour..
ACTIVITIES 11. People have compared heat conduction to a human chain that passes a bucket of water from per-
13. Greenhouses are essential to farming nowadays. Make a slide show about these constructions.
son todoes. person. move, but the water CanThe youpeople explaindo thisnot comparison?
What are they What concepts physics do they use? Whatfor? is planted in them?of Give an oral presentation of the slide show in class.
12. Find information about a system called underfloor heating. Why is it installed under the floors in houses? Why are air conditioning vents installed in high locations? Discuss your answers with your partner and after reaching an agreement share your answer with the whole class.
14. Make a poster tto o explain how the human ear works. In particular, show the transference of sound to mechanical energy that occurs in our eardrum.
UNIT 7
WORKSHEET
unit ’s workDownload this unit’s sheet and do activities 12 and 13.
Thermal Expansion
When an object absorbs energy in the form of heat, its temperature can increase or it can change its state of aggregation. (You studied this in Unit 2.) An increase in temperature implies an increase in the agitation of particles. This producess changes in the properties of the object. produce
THINK AND REASON If you put a dented (but not broken) ping pong ball into a pan of boiling water, the dents disappear. The ball contains the same amount of air when it is dented as when it is repaire repaired. d. Why have the dents disappeared?
To understand what happens when a substance absorbs thermal energy, you must take into account what happens at both a macroscopic and molecular scale. The object absorbs thermal energy. Therefore, the agitation of its particles
As a consequence, the separation between the particles
Macroscopically, the increase in agitation corresponds to an increase in temperature. The increased separation between the
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increases.
increases.
particles results in an increase in the volume of the object. We call this expansion. Final temperature
Initial temperature
Initial length
Final length
>
Initial length
The more intensely united the particles, the less the material expands. Remember what you know about the states of aggregation. This will help you understand why gases expand more than liquids and why liquids expand more than solids.
ACTIVITIES 15. Find information about the expansion joints used in paving, bridges and buildings. Record a video talking about the importance and usefulness of these elements.
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3 .1. The Thermomet Thermometer er Liquid thermometers thermometers are are instruments that measure the temperature of an ob ject. They are based on the expansion expansion of a lliquid iquid when its ttemperatur emperature e varies.
The molecules collide in the two liquids and against the wall of the thermometer. This allows the transfer of energy between the two liquids by conduction until they reach thermal equilibrium.
When the alcohol absorbs thermal energy, it expands and rises up the thermometer tube. The tube is graduated and indicates the temperature of the alcohol. This therefore tells us the object. temperature of
WORKSHEET unit ’s workDownload this unit’s worksheet and do activities 14 and 15.
REMEMBER The equivalence between Celsius and Kelvin degrees is: T (K) = T (ºC) + 273
The Celsius temperature scale uses scale uses the melting point of ice and the boiling point of water as a reference. It divides the difference between these two temperatures by one hundred to define one degree Celsius (°C).
EXPERIMENT 4. You are going to make a homema homemade de thermometer and ca calibrate librate it in degrees centigrade. You will need: water, rubbing alcohol, colorant, a plastic bottle, plasticine, a straw, a sheet of paper, a roll of adhesive tape and a dropper. Mix equal parts of water and alcohol. Dye it with the colorant and fill the bottle with the mixture. Construct an instrument like the one in the picture. The modelling clay must seal the bottle opening completely completely.. Partially fill the straw with liquid using the dropper dropper.. Put some ice into a bowl and wait for it to partially melt. Put the bottle into the bowl. Mark the height of the liquid in the straw as 0 ºC. Now do the same with a bowl containing boiling water and mark the height of the liquid in the straw as 100 ºC. Now divide the distance between 0 ºC and 100 ºC into equal parts. • Can we use our thermome thermometer ter to meas measure ure a temperature temperature below 0 ºC? • Put your thermometer thermometer on top of of a heated radiator and comp compare are your measur measurement ement with the value giv given en by a commercial thermometer.
UNIT 7
Energy in Our Lives Lives WORKSHEET
Throughout our lives we consume energy in various forms: heat, light, motion, sound, etc. sound, etc.
unit ’s workDownload this unit’s sheet and do activity 16.
THINK AND REASON The map below shows the energy consumption per person in each country of the world.
than 400 million Btu/person per year More
250-400 million Btu/ Btu/person person per year 150-249 million Btu/ Btu/person person per year 75-149 million Btu/person per year 25-74 million Btu/person per year 10-24 million Btu/person Btu/person per year 5-9 million Btu/person per year Less than 5 million Btu/person per year
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• Which countries’ citizens consume the most energy per person? Is there a relationship between this consumption and the degree of the country’s economical and social development? • China is the first or second economic world power power,, but iits ts energy consumption per person is relatively low. Why do you think this is?
DID YOU KNOW?
Approximately 25% of the energy generated in the world each year dissipates as it is generated or during its transportation. Therefore, 25% of the energy generated is useless energy.
Humans obtain the energy we consume from different resources we call sources of energy. An energy source is source is any resource from which humans extract energy that transforms in accordance with their needs. Energy sources can be renewbe renewable or able or non-renewable non-renewable.. Nowadays, Nowada ys, the energy obtained from these sources has three uses: • We mainly use non-renewab non-renewable le energy sources for transport. • We mainly use non-renewable energy sources and a smaller proportion of of renewable sources to produce heat produce heat for for the central heating in heating in our homes and industrial and industrial facilities. • We produce electrical energy for electrical devices devices with renewable and non-renewable non-renewab le sources.
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4 .1. Non-Renewab Non-Renewable le Ener Energy gy Sources Non-renewable energy sources are sources are finite. This means that we consume them at a faster rate than they are created, so they eventually run out.
COAL
NATURAL NA TURAL GAS
URANIUM
We extract oil from under-
We extract coal from un-
We extract gas from un-
We obtain uranium from
ground wells. We use it to obtain different combustible substances (fuels such as petrol, diesel and kerosene), but also plastics or asphalt.
derground mines. We mostly use it to obtain electrical energy in thermal power stations.
derground wells. We use it for cooking, central heating and industrial furnaces. We also use it to obtain electrical energy in thermal power stations.
underground mines. It has to be concentrated. It is the main fuel in nuclear power stations. These use nuclear fission to obtain electrical energy.
OIL
We use the term fossil fuels to refer to oil oil,, coal coal and and natural gas. gas. Fossil fuels and uranium uranium are the most widely used non-renewable energy sources at present.
WORKSHEET Download this unit’s workunit ’s work-
Oil is the main energy source, as it allows humans to obtain the fuels needed to transport people or goods.
sheet and do activities 17 and 18.
ACTIVITIES 16. The following diagram shows the origin of the energy consumed in the world in 2006. What percentage of the energy used is from a nonrenewable source? 17. State three examples from your everyday life where you consume energy for each one of the three main uses described above. Share them with the rest of the class and make a list in your notebook with all the examples. 18. Investigate th the e controversy that aarose rose in the Canary Islands about the possibility of surveying for oil deposits there. Prepare a brief oral presentation in favour of these operations and another one against them and show them to your class.
Natural gas 20.5% Coal 26.1%
Nuclear 6.2% Biomass and Renewable 12.9%
residues 10.1 10.1 % Hydraulic 2.2%
Oil 34.3%
Solar, wind and geothermal 0.6%
UNIT 7
4 .2 .2.. Rene Renewable wable Ener Energy gy Sources Renewable energy sources are inexhaustible. This means that we consume them at a lower rate than nature creates them, so they never run out.
SOLAR
SOLAR THERMAL
GEOTHERMAL
TIDAL
PHOTOVOLTAIC
Sunlight heats the water circulating through pipes. We can use this hot water directly in the kitchen and bathroom or for central heating.
The Earth’s internal heat transforms liquid water into steam. The steam propels turbines, which transform the motion into electric current.
The tides, waves and currents in the sea move the blades of underground turbines. The turbines then transform this motion into electric current.
Solar panels convert sunlight into an electric current. This process can only take place during daylight hours and this is one of its major problems.
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BIOMASS RESIDUES We can transform the waste from crops, cattle or water treatment into fuel for central heating or industrial furnaces.
BIOFUELS
LAND OR SEA WIND
HYDROELECTRICAL
We can convert crops such as sunflowers, soya or sugar cane into fuels like bioethanol or biodiesel. They substitute fossil fuels.
Wind moves the blades of the turbines, which transform this motion into electrical energy.
The water in dams flows through pipes with turbines at the end. The turbines transform this motion into electrical energy.
ACTIVITIES 19. Choose one of the eight types of renewable energy and create a presentation about it. The presentation can be: a slide show, a poster, a documentary video, an audio production (similar to a radio show), a blog, etc.
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4 .3 .3.. Rene Renewable wable or Non-Renewab Non-Renewable le Energy?
Access to energy is fundamental to the development of societies. Over the next few pages, we are going to compare different aspects of renewable and non-renewable energy sources. This will help you to reflect on how humans should manage the way we obtain energy.
WORKSHEET unit ’s workDownload this unit’s worksheet and do activities 19 and 20.
A. Geographical G eographical and Economic Economic Aspects One of the main objectives of every country in the world is to have a large enough energy supply. They need energy for their industries and services, and for their citizens to have an adequate standard of living.
THINK AND REASON Observe the following data from 2014 on the main oil-producing countries and the countries that produce electricity from renewable sources: Main producers of oil (percentage of the total number of barrels in the world produced by each country) USA
13.1
Saudi Arabia
13.0
Canada
4.9
China
4.8
Iran
Gigawatts
4.2
125 105 100 86 75 50 32
4.1 25
Iraq
3.7
153
150
12.2
Russia
United Arab Emirates
Main producers of electrical energy from renewable sources
32
31
31
Kuwait Mexico
3.5
0
China
USA Germany
Italy
Spain
Japan
India
3.1 Source: REN 21
Source: BP
• No European country is an important oil producer, but three of them (including Spain) are large producers of electricity from renewable sources. Do you think there is a relationship between these two facts? • Why do you think that China and the United States are investing in renewable energies, even though they produce lots of oil? Why aren’t countries such as Iran, Iraq and Kuwait producing renewable energies? Renewable energies are not limited to specific territories. They can be used by all countries. Renewable energies allow many countries to overcome their foreign energy dependence. dependence. This dependence means they have to buy fuel from other countries and are therefore partially dependent on them. There is a lot of economic power associated with energy. Large companies and individual countries try to obtain the best position and ensure they have sufficient energy resources. UNIT 7
B. Environmental Aspects Any method of obtaining energy produces a change in the environment. In particular, non-renewable energies cause serious problems with grave consequences for mankind and nature. Climate Change
DID YOU KNOW?
The ITER project is an international project to obtain energy through nuclear fusion. fusion. This energy source would be almost inexhaustible and would not generate environmental problems. There is currently intense research into nuclear fusion. Scientists are slowly resolving the enormous technical problems it presents. However, they are still not ready to confirm that it will become a stable new source of energy for mankind.
This is the greatest environmental problem humans face at present. Burning fossil fuels emits carbon dioxide (CO2), which accumulates in the atmosphere. This gas absorbs and then emits again part of the solar radiation which should leave the planet. This causes the temperature to rise, leading to droughts, torrential rains, tornados, polar ice melt, alterations in the lifecycle of plants and animals, etc.
Part of the heat is lost in space
Solar energy
Gases with greenhouse effect
The Earth and the oceans absorb solar radiation The Earth and the oceans radiate heat (infrared radiation)
The greenhouse gases retain part of the heat
Acid Rain Burning fossil fuels emits nitrogen oxide and sulphur sulphur dioxide dioxide into the atmosphere. When these oxides come into contact with the water in clouds, they transform into sulphuric and nitric nitric acids. acids. These acids return to the ground dissolved in rainwater. This causes serious problems in lakes, soils and stone buildings.
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Nitrogen oxides
Formation of sulphuric acid and nitric acid
Sulphur dioxides
WORKSHEET Acid rain
Download this unit unit’s ’s worksheet and do activities 21 and 22.
Radioactive Waste Waste and Nuclear Accidents Nuclear power stations produce highly carcinogenic and toxic radioactive waste. This waste can be active for thousands of years. In addition, the power stations can have accidents if their reactors are out of control. This has very serious consequences consequences for humans and the envir environment. onment.
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C. Technological Aspects Non-renewable energies use consolidated technology. Petrol or diesel engines and electricity-generating thermal or nuclear power stations are perfectly linked to our societies. Renewable energies must still complete this adaptation.
THINK AND REASON The graph shows electricity consumption in Spain over a single day. • Describe the graph and interpret the peaks and troughs in electricity consumption, thinking about the Spanish lifestyle. • What is the problem with renewable energies to meet the peak hours of demand? Does the wind blow with the same force all the time?
36000 34000 32000
) W30000 M ( 28 000 d n 26000 a m 24000 e D 22000
20000 18000 12
0
2
4
6
8
10
12 12
14
16
18 18
20
22 22
0
2
Source: REE
Renewable energies currently provide around 51% of the electricity consumed in Spain. To increase this percentage, we need to implement two measures: • Improve energy storage. We need to make energy from renewable sources available when the wind is not blowing or there is no sunlight. • Modify the consumption habits of habits of the population. We must commit to using energy at the most propitious times for renewable energies. As well as obtaining electrical energy from renewable sources, the other great change to our energy consumption will come from the use of electric cars. cars. There are currently vehicles which are completely electric and there are others that are hybrids hybrids.. These have two engines: one is for fossil fuel and the
ENERGY 2.0
Go to the following link: goo.gl/hUwx You can see the origin of the electrical energy consumed in Spain hour by hour for any day of
other is electric. These vehicles charge their batteries by plugging them into an electric current with a normal socket or a fast-charge socket. The main problem is still their battery range, but scientists are working hard to improve this. At the moment they need to be recharged approximately every 200 km. As a result, they are not very useful for long journeys.
the year. Work with your partner to locate in which month of the year we consume the most and try to explain it.
ACTIVITIES 20. Renewable energies present far fewer problems for the environment than non-renewable ones. Investigate and describe the environmental problems presented by solar, wind, hydroelectric and biofuel energies.
21. Look at the following link: goo.gl/hUwxjp goo.gl/hUwxjp Com Compare the origin of the electrical energy consumed in Spain during the day and during the night. Now compare the electrical energy consumed in a winter day and in a summer day.
UNIT 7
The Need for Energy Saving
WORKSHEET
Mankind is consuming increasing amounts of energy. Obtaining this energy is causing for serious problems and this is forcing us to consider energy saving as a priority our societies.
unit ’s workDownload this unit’s sheet and do activities 23 and 24.
THINK AND REASON Observe the followi following ng figures: World energy consumption (1970-2025) 800
600 u t B n o i l l 400 i r d a u Q 200
World population Energy consumption
0 Source: Saladié, O.; Oliveras, J. 2010
19 1970 70 1197 975 5
19 1980 80 1985 19 199 9 0 19 95 95 200 2005 5 20 2010 10 2015 2015 20 2020 20 20 2025 25
Source: Saladié, O.; Oliveras, J. 2010
Based on the data on the map, what differences do you think there are between a North American person’s life and that of an African person? The world’s population is increasing. Do you think world energy consumption will continue to increase? Why? Who has a greater responsibility to save energy: a European country or a South American one?
The current growth in world energy consumption is unsustainable. The main reasons are as follows:
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Climateofchange is aScientists real threatbelieve to the future mankind. we have to reduce the burning of fossil fuels dramatically. Consequently, we have to reduce the energy obtained in this way.
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Fossil at fuels finite. finite . If we them our are current rate, theyconsume will run out in the medium term. In addition, these resources are very useful for obtaining plastics, for example. Some experts consider it a waste to burn them as fuel.
Renewable energies are cannot an excellent energy source, but they meet the growing energy demand. There is currently a lot of research into increasing increasi ng its i ts efficiency and finding findin g new energy sources that complement them.
U NIT 7
5 .1. How Can W We e Save Energy Energy? ? There are many things we can do in our everyday lives to save energy.
MOST EFFICIENT
AT HOME HOM E
Energy consumption lower than 30% of the average
A++
• Always use electrical appliances when when they are full and buy the t he most effi cient ones. on es. Look Loo k at the diagram explaining the meaning of each energy class so you can interpret the meaning of the labels on your appliances.
A+
Between 30 and 42% A
Between 42 and 55% B
• Recycle everything you can. • Cook with a pressure cooker. Don’t pre-heat pre-h eat the oven if it isn’t necessary. Put the lid on pans when cooking on the hob.
Between 55 and 75% C
Between 75 and 90% Between 90 and 100%
D
• Use low-energy low-energy lighting lighting and only turn on the lights when you need them.
E
• switched Don’t leave plugged in when they are offdevices or on standby.
Between 100 and 110% F
• In winter, winter, put the heating heating on between 19 and 21 ºC. Put the air conditioning on at 7 or 8 ºC below the external temperature.
Between 110 and 125% G
Higher than 125%
LEAST EFFICIENT
TRANSPORT
SHOPPING
Walk or ride a bike for short journeys. Share the car with other passengers. Use public transport.
Try to buy locally produced food that is in season. When buying clothes and technology, only buy goods you really need.
IN YOUR CITY, CIT Y, AT AT WORK, AT SCHOOL SCHOO L When you see bad energy habits, always tell someone who can change them. For example, the mayor in your
town, your headteacher, etc.
ACTIVITIES 22. Find information on the internet about world en-
23. Create a list of ten energy-saving measures to
ergy consumption from the mid-19th century until the present. How much has this consumption multiplied? Give several reasons for this increase. Compare your conclusions with your partner.
apply in your school. Compare all the lists in the class and create a new final list of the ten best measures. Make a presentation with the items in the list and show it to the class.
UNIT 7
MIND MAP Download and print the worksheet you will find in the OLC to complete the concept map of the unit. ENERGY
quantifies the Capacity to produce changes
its properties are it tranforms
it transfers
it dissipates
it is conserved
how
Chemical energy it is related to
Temperature
in the
...
in the ground
Electrical energy Fuels
... energy
Thermal energy ...
in the form of ... energy
Potential energy
it is used
it can be produced by
it can be transferred by
...
Convection
Electrical energy
...
... sources
... sources
LOOK AROUND YOU
Wind Pro Provides vides El Hierro with All Its Electricity for Four Hours
The island of El Hierro reached a world record. It is the first isolated territory in the world to achieve 100% of its energy supply from a renewable energy source. At 12 o’clock midday on Sunday 9th August, the Gorona del Viento hydro-wind dro-win d power station began to generate the entire electricity supply for the island from clean sources. It maintained the supply for four hours. The technicians achieved this thanks to the combination of two sources of renewable energy: hydraulic power from the Gorona power station coupled with a wind farm with five wind turbines. This system will save 80 million euros over the next two decades, because 6000 fewer tonnes of diesel will be burned each year year.. The project cost 82 million euros and represents an innovativ innovative e technological achievement. Source: El País. 20th August 2015.
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Questions a) Where is the island of El Hierro Hierro?? What is the size of its population? Does it have any important meteorological characteristics? b) What positive environmental aspects does a completely renewable energy supply have have?? Why do experts believe that different renewable energies should always be combined to work together? c) Do you think that your city could be supplied only by renewable energy sources? Discuss your answer with your partner and make a proposal for your city's mayor on how your city can be supplied only by renewable sources.
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LABORATORY WORK
Energy Energy,, Thermal Conductivity and Expansion Objective The objectives of this experimental class are to: study the transformatio transformation n of energy from one kind to another; compare the conductive capacity of different metals; and experimentally observe the process of thermal expansion. Material Glass jar with lid (a jam jar jar,, for example), sand, thermal conductivity apparatus, apparatu s, Bunse Bunsen n burner, wax or paraffi n, and expan expansion sion ball and ring apparatus. Methodology a) Fill jar with sand to approximately thirdthe full.jar Measure the theglass temperature of the sand in the jar.one Close and shake the sand hard for one minute. If you get tired, pass the jar to one of your classmates to continue shaking it. Aer one minute, open the jar quickly and measure the temperature of the sand again. b) Use the thermal conductivity measurement apparatus. (Remember, thermal conductivity is the capacity of different materials to conduct thermal energy.) Put a portion of wax or paraffin on the end of each met metal al wand wand.. Heat the ce centre ntre of the apparatus with the Bunsen burner. Observe the order in which each portion of wax melts. c) Finally Finally,, we are going to monitor the thermal expansion of a solid.
To do this, we are going to use a ball and ring apparatus. First, check that the ball can pass through the ring. Now Now,, with the ball inside the ring, heat the ball with the Bunsen burner for a few minutes. Then try to take the ball out of the ring.
Thermal conductivity measurement apparatus
Metal ball and ring apparatus
Questions • In experiment a), what energy transformation has taken place place?? The grains of sand have increased in temperature. What does that indicate about their properties properties??
• In experiment b), what heat transference mechanism takes place? Put the different materials of the apparatus in order, from best to worst thermal conductor and check your results with your partner.. What does it mean at a particle level that a material is a good heat conductor partner conductor?? • In experiment c), why can’t you take the ball out aer you have heated it? One pupil explains it in the following way: ‘When we heat the ball, its particles increase in size. As a result, the volume of the ball increases and cannot be removed from the ring.’ Is this explanation correct? Can you clarify what really happens? Discuss this with your partner.
UNIT 7
FINAL ACTIVITIES
Basic Activities 1. Design an A3-sized poem poster which includes several images of systems with changes happening in them. Explain the types of energy there are. The title of the poster is: ‘Where There Is Change, There Is Energy.’ It should contain a poem about energy and its transformations. On the back of the poster, write a list of the sources you have used to make the poster. 2. There is one receptacle containing three litres of water at 20 ºC on a hot plate and another receptacle containing one litre of water at 20 ºC on an identical hot plate. Twenty minutes later: a) Will the same amount of energy be transferred to both receptacles? b) Will the water in the two receptacles be the same temperature? Which one will be higher? c) Will the molecules of water in both receptacles have the same kinetic energy? energy? Which one will have more? d) Can you compare the above situation to a father sharing 100 euros with his two children and another father sharing 100 euros with his five children? Explain the analogy. Take turns with your partner to answer the questions and reach an agreement.
3. A car travelling at 80 km/h possesses a large amount of kinetic energy. When the driver steps on the brakes and the car stops, what is this energy transformed transform ed into? Is it transferred to another object or does it dissipate? Is the principle of energy conservation true here? Why? Compare your answers with your partner. 4. We have all burned ourselves eating croquettes at some point. When we pick them up with our fingers,, they don’t feel very hot. However, when fingers we bite into them, we burn our mouth. Does the
contact with the iron for a short time? What do we mean by: 'thermal equilibrium will be reached' by maintaining contact?
6. A 100-gram piece of iron at 90 ºC is put into a receptacle containing a litre of water at 25 ºC. Which way does the transfer of heat go? Describe how this energy transference transference occurs. 7. The image shows a simplified explanation of the movement of tectonic plates. Explain the diagram and indicate the implied heat transfer mechanism.
8. Why does installing an awning over windows and terraces help to reduce the temperature inside the house? Which thermal energy transfer mechanism is important here? Discuss this with your partner. 9. A mechanic wants to join a bar and a ring together. He cannot remember if he has to adjust the hot ring inside the cold bar or the cold ring inside the hot bar. Can you help him? 10. With the help of your partner, search for information on the current situation and future prospects for energy from nuclear fission. Are there more or fewer nuclear power stations in the world now? Why do you think this is?
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coating on the croquette have a thermal conductivity similar to metal or to plastic plastic?? 5. The iron in the picture has reached a temperature of 120 °C. Working in pairs, answer the following questions: How will the temperature on the thermometers change after coming into
1 82
11. In December 2015 there was a Climate Summit to find solutions to the problem of climate change. Prepare an elevator pitch to convince the heads of government of the need to change our energy sources and our current mode of consumption.
U NIT 7
Advanced Activities
Consolidation Activities 12. Explain the energy transformation that occurs when somebody jumps down a slide at a water park. How is energy being transferred or dissipated in this situation? 13. Record a video explaining energy conservation based on the functioning of a light bulb. Pay attention to three aspects: the electricity supply, the emission of light and the temperature the bulb reaches when it is on. 14. Wo Work rk in pairs. Draw a bar chart showing the division between electromagnetic (light), sound and thermal energy in a mobile. Estimate the percentage of each type of energy as if they were proportional to the time the mobile emits light or sound and dissipates energy in the form of heat. 15. We have three different liquids to make a thermometer. Liquid A triples in volume when it goes from 15 to 50 ºC. º C. Liquid B multiplies its volume by 1.2 in the same process. Liquid C multiplies its volume by 6. Which is the best liquid to make the thermometer? What is the problem with the other two? Think how long the thermometer would have to be if you used those liquids. 16. Observe the data on energy consumption in the home. Where do you think it is most feasible to save energy? Suggest two energy-saving measures for each section on the graph. Share them with the class and make a poster with the best proposals.
17. Which consumes more energy: a television with a 10-inch 10 -inch screen or one with a 40-inch screen? 18. David takes an orange out of the fridge. He squeezes it and puts the glass of juice in the microwave microwa ve for thirty seconds. Andrew puts th the e whole orange in the microwave for the same amount of time and then squeezes it. Which receives receives more thermal energy: the glass of juice or the whole orange? Which glass of juice will have a higher temperatur temperature? e? Explain your answer using the principle of energy conservation. 19. Think, pair up and share: indicate three situations in your everyday life where the energy dissipation is positive and three situations where it is negative. Share your situations with your partner and then with the whole class. 20. Some isothermal bottles consist of a container surrounded by a vacuum chamber. In other words, there is an absence of matter inside the chamber. Explain why this system keeps the liquid inside the flask at a constant temperatur temperature. e. 21. At the beginning of December 2013, there was very little wind in Spain. A few days later, an explosive cyclogenesis produced an enormous amount of wind. What does this information tell you about the limitations of wind energy? We define drought as the absence of rain for a long period of time. What energy source does drought affect? 22. Reflect on the importance of being able to store electrical energy at a competitive price to improve the implementation of renewable energies. Write a newspaper article. Y You ou can download the parts of an article from the OLC.
1% 8% 32%
Heating Hot water
27 %
Light Electrical appliances
26 %
Cooking
6%
Air conditioning
UNIT 7
USE YOUR SKILLS
The Greenhouse Effect: Reality or Fiction? It is a fact that the average temperature of the atmosphere has increased. People often say that the main cause of the rise in temperatur temperature e in the 20th century is carbon dioxide emissions. A student called Andrew is interested in the possible relationship between the average temperature of the Earth’s atmosphere and the carbon dioxide emissions on Earth. He finds the following graph in the library. Based on this graph, Andrew concludes that it is true that the rise in the average temperature of the Earth’s atmosphere is caused by the increase in carbon dioxide emissions. Carbon dioxide Temperature
) s r n a o e i y s r s i e m p e s e e d n o n i x o t i f d o n s o n b o r i l a l i C b (
20
15.4
10
15.0
A E v a e r r a t h g ’ e s a e t t m m o p s e p r h a t e u r r e e ( º o f C t ) h e
14.6 18 1860 60 18 1870 70 1880 1880 189 1890 0 19 1900 00 19 1910 10 1920 1920 1930 1930 19 1940 40 1950 1950 1960 1960 1970 1970 198 1980 0 1990 1990 years
Working in pairs, answer the following questions about Andrew's work:
Question 1 What information in the graph supports Andrew’s conclusion?
Question 2 Another pupil, Joanne, does not agree with Andrew’s conclusion. She compares the two lines and says that some parts of the graph do not support his conclusio conclusion. n. Select one part of the graph which does not confirm Andrew’s conclusion. Explain your answer answer..
Question 3 Andrew insists that the cause for the rise in the average temperature temperature of the Earth’s atmosphere is the increase in carbon dioxide emissions. But
must check that the other factors influencing the greenhouse effect have remained constant.’ Name one of the factors fac tors Joanne is referring to.
Question 4 Andrew wants to start a debate about global warming at his school. He wants to invite six participants to the debate. Which six professions do you think would be best to explain the entire phenomenon? Follow the example: A biologist can talk to us about how climate change is affecting animals.
Question 5 Andrew reads that ‘climate change’ is the preferred term nowadays, not ‘global warming’. What do both terms mean? Why do you think it is preferable to use ‘climate change’? Use the
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Joanne thinks his conclusion is premature. She says, ‘Before accepting this conclusion, you
1 84
following structure to answer the questions: Global warming means...
U NIT 7
Mobilise the World and Save S ave Energy Objective The objective of this task is to create an energy-saving campaign involving your friends, classmates, families, etc. You can do this task individually,, but it will be much more effective if individually the whole class does it as a team.
Final Product The final product you must create is a sign motivating people to join the energy-saving campaign. You You must also think of a way to count the people who join your campaign.
Step by Step 1. Make a list of fi five ve energy-saving goals yyou ou are going to propose to various people you know. These five goals must be feasible, be effective and a nd have va varying rying d degrees egrees of diffi culty. For example, a simple goal might be: ‘I turn off all the lights I don’t need. I don’t waste a single photon of light.’ 2. Assign a medal to each goal. For example, wood, plastic, bronze, silver and gold medals (from the simplest to the most complex goal). 3. Create an attr attractive active logo ffor or each goal. Draw the five medals with their respective logos in the centre. For instance, you could set the example goal above to earn the plastic medal. The diagram shows a possible logo. 4. Create a sign showing the five medals with the five goals next to them. If the whole class is doing the project together, you can hang the sign in a prominent place in your school. In that way, all the pupils in the school can join the ca campaign mpaign..
Competency Task 5. Make an individual medal count counter er or one fo forr the whole class. If it is for the whole class, make a poster and put it up in the classroom. 6. Use all your resources. F First, irst, choose the goal you are going to achieve, photograph the corresponding medal and make stickers, badges or something else with this photo. Share these emblems among people you know who promise to reach the goal. 7. Ask yyour our teachers if you can go to other classes in the school to explain the project. 8. Every time somebody friend,one family member, etc.) promises(pupil, to achieve of the goals, add them to your medal counter counter.. 9. Tell everyone involved how many medals you have earned. Encourage everyone you know to reach a common goal. 250 medals? 500 medals? 1000 medals? With every medal you earn, you are doing the Earth a favour. Earn as many as you can!
Self-Assessment Evaluate your work and your classmates' work with the guidelines that you can download from the OLC.
UNIT 7
Publicacione Publicacioness personalizadas a tu medida
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O M I O P R E M O M
S I N E D U C A C I Ó Ó 1 5
2 0
d e l r d a d o r
® g g a n a l o o k , c a c i ó B B ó n a t r a u d S m E E M O S I M o S L T A e m i o G I T P r e D I G O D S R U A A C I R E T O R L J O R R E D I T
Una nuev nueva a forma de d e leer... Una nueva forma de aprender
E M E E A Ó N E I Ó a s C R C o g í a o D E C T e c n o l a a d T d d i i l a a l d a u . l a m o la m e l a e e n l a a r a p p s o s s r e c u r e y r
es la primera SmartBook® es SmartBook®
¿Te imaginas un libro de texto adaptado a las necesidades individuales de cada estudiante?
y única experiencia de lectura y aprendizaje adaptativo diseñada para cambiar la forma en la que los estudiantes leen y aprenden, rompiendo con el camino lineal de los libros de texto tradicionales y adaptándose a las necesidades y al ritmo de cada estudiante.
Porque el aprendizaje lo cambia todo
SmartBook®
¿Qué es? SmartBook® es una herramienta herramient a de aprendizaje adaptativo que combina
una revolucionaria tecnología desarrollada de sarrollada por McGraw-H McGraw-Hill ill Education con c on un libro digital interactivo. SmartBook® analiza la forma en la que lee y aprende el estudiante y, en función de sus respuestas a preguntas sobre lo estudiado y la seguridad sobre sus conocimientos, le va guiando a través de los contenidos del libro, de una manera personalizada y adaptada a su propio ritmo de aprendizaje, para que cada minuto que pasa el alumno estudiando sea lo más efectivo posible.
¿Cómo funciona? SmartBook® consta de varias fases:
Lee En la fase de lectura, el estudiante es guiado a través del texto para que lea de una manera adaptada a sus necesidades. En SmartBook® SmartBook® el el estudiante tiene acceso al texto completo, pero se le mostrarán áreas resaltadas en amarillo que indican el contenido en el que debería centrar su estudio en ese momento concreto. Las áreas resaltadas del texto van variando en función de sus respuestas en la parte práctica, subrayando nuevos temas y conceptos de más nivel, una vez que el estudiante ha demostrado el dominio de los conceptos esenciales del tema.
2
Practica En la fase de práctica, los estudiantes afianzan lo aprendido hasta el momento realizando una serie de actividades de diversa tipología. Antes de responder, se pedirá al estudiante que evalúe el grado de seguridad sobre sus conocimientos:
Sé la respuesta
Eso creo
No estoy seguro
Ni idea
En función de las las respuestas a esas preguntas, el grado de seguridad que establezcan y otros datos que va recogiendo el sistema mientras los estudiantes trabajan, SmartBook® SmartBook® irá ajustando el camino de aprendizaje de cada estudiante adaptándolo a su ritmo y necesidades y determinando cuál será la siguiente pregunta.
Lee
Prac t i c a
De vuelta en la fase Lee, el estudiante se encontrará con nuevas partes del texto resaltadas en amarillo, que indic an el nuevo contenido a estudiar, y otras resaltadas en verde, que son los temas o conceptos c onceptos que el estudiante h haa demostrado que domina al responder correctamente a las preguntas en la fase de práctica. Subrayado amarillo: muestra el contenido que es importante para el estudiante en este momento. Subrayado Subray ado verde: muestra el e l contenido que el estudiante es tudiante ha demostrado que domina realizando preguntas en la fase de práctica. La mejor manera de estudiar est udiar con SmartBook® SmartBook® es es ir pasando de una fase a otra hasta completar la unidad. La propia herramienta herramient a ayudará al estudiante a identificar ccuándo uándo ha llegado el momento de cambiar de fase.
Repasa Para asegurar el dominio de los temas y la retención a largo plazo de los conceptos aprendidos, en esta fase el estudiante repasa en forma de actividades el contenido importante que el sistema ha identificado que es más probable que olvide.
Informes
Informes completos sobre el progreso del curso Profesor Los informes del profesor le permiten conocer en tiempo real las fortalezas y las debilidades de sus alumnos de manera individual y a nivel global, y adaptar así sus clases y tutorías.
Estudiante Los informes del estudiante proporcionan detalles sobre su progreso, sobre los temas que domina y los que necesita estudiar más, para que pueda maximizar su tiempo de estudio.
Beneficios
Todo son ventajas Para el profesor:
Para el estudiante:
• Mejora la calidad y la productividad de las clases.
• Ofrece Ofrece el contenido adecuado para cada estudiante en el
• Facilita Facilita la adaptación de las clases al nivel y necesidades de los alumnos.
• Ayuda Ayuda a prevenir el posible fracaso escolar y a remediarlo antes de que ocurra.
• Mejora Mejora el rendimiento de los alumnos y su nivel de notas.
momento preciso para maximizar el tiempo de estudio.
• Excelente Excelente preparación para clase y para los exámenes. Ayuda a retener conceptos clave a largo plazo. • Ayuda
• Ayuda Ayuda a conseguir mejores notas. • Herramienta Herramienta online: sin sin descargas, sin necesidad de grabar el progreso.
• Acceso Acceso en cualquier momento a través de una conexión a Internet y desde múltiples dispositivos.
• Interfaz Interfaz intuitiva y atractiva. Es divertido, porque permite competir con otros usuarios. • Es
Integra SmartBook® en tu curso La mejor manera de sacar el máximo provecho a las ventajas de SmartBook® es crear una clase a la que se apuntarán tus alumnos. Los estudiantes pueden trabajar independientemente independientemente o asociados asoci ados a tu clase, pero la experiencia es mucho más positiva y productiva si se integra SmartBook® como una parte más de la asignatura. Te Te damos algunas opciones o ideas:
...... ... antes de ir a clase
Puedes decir a tus alumnos que estudien con SmartBook® SmartBook® antes antes de ir a clase. Así, podrás basar tus clases en los datos que obtengas con la herramienta.
... como deberes Puedes presentar el contenido en clase y después, a modo de deberes, decirles que estudien el tema con SmartBook®. Posteriormente, SmartBook®. Posteriormente, en función de los datos que obtengas sobre el progreso, las fortalezas y las debilidades de tus alumnos, podrás reforzar ciertos contenidos y hacer un seguimiento general e individual de lo que realmente se ha aprendido.
... antes del examen Puedes dar la unidad completa y recomendar a tus alumnos que utilicen SmartBook® SmartBook® para para preparar el examen. Si tienen examen de final de curso, recuerda a tus alumnos que utilicen regularmente la fase Repasa para Repasa para estar preparados cuando llegue el gran día.
Si tus alumnos tienen dificultades para acceder a Internet, una buena solución puede ser dedicar periódicamente tiempo de clase a SmartBook® en el aula de informática.
McGraw-Hill Education
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