The Science Hub - SARASWATI HOUSE

(An imprint of New Saraswati House (India) Pvt. Ltd.)New Delhi-110002 (INDIA)

TEACHER’S MANUAL

Class 5

Neha JindalMSc, M Phil, BEd

Science HubThe

(An imprint of New Saraswati House (India) Pvt. Ltd.)

R

First published 2016

ISBN: 978-93-5199-716-0

Preface Th e purpose of � e Science Hub series (1 to 8) teacher’s resource pack is to empower teachers to make classroom teaching a holistic experience. It will enable teachers to explain the chapters in the most eff ective way, which will not only impart knowledge, but also ignite interest in the minds of young learners towards the subject. A wide array of resources complement these manuals, which makes learning an interesting process instead of a routine chore.

Teacher’s ManualTeacher’s Manual resources have been carefully prepared with an aim to make the process of teaching and learning interesting and intriguing for the teachers and learners alike. It comprises detailed lesson plans and answers to the coursebook along with solved worksheets and model test papers. Th ese have been prepared keeping in mind the explanation of the concepts and the level appropriateness of the topics. Easily available teaching aids are used to make teaching and learning an interactive and lucid process.Th e lesson plans give a topic-wise explanation of each chapter. Its components are:

• Warm up section guides the teacher to start the topic in an interesting way.

• Speci� c learning objectives give the list of measurable aims of each chapter, which should be achieved aft er teaching the chapter.

• Concept explanation gives a detailed method of explaining the important concepts of the chapter using various teaching aids.

• Reinforce section allows the teacher to check the progress of the concepts learned by the students with the help of textual questions and worksheets and allows them to revisit and revise the concepts, if required.

• Explore section helps the learners to do various activities , oft en taking them beyond their classroom learning.

Teacher’s CDTeacher’s CD comprises animations, activities, fl ip book, detailed lesson plans and answers to the coursebook along with solved worksheets and model test papers.

Web SupportTh e web support consists of worksheets, model test papers, and answers to worksheets and model test papers. Th ese would help teachers in assessing students on the concepts taught in the class.

Contents S. No. Chapters Pages

1. Growing Plants 5

2. Food and Health 12

3. Animal: Habitat and Adaptation 19

4. Bones and Muscles 25

5. Our Nervous System 32

6. Safety and First Aid 38

7. Solids, Liquids and Gases 44

8. Rocks and Minerals 49

9. Measurement 56

• Model Test Paper 1 64

10. Soil 66

11. Force and Energy 73

12. Air and Water 81

13. Earth, Sun and Moon 88

14. Light and Shadows 96

15. Natural Disasters 102


Contents S. No. Chapters Pages S. No. Chapters Pages

1. Growing Plants 5

2. Food and Health 12

3. Animal: Habitat and Adaptation 19

4. Bones and Muscles 25

5. Our Nervous System 32

6. Safety and First Aid 38

7. Solids, Liquids and Gases 44

8. Rocks and Minerals 49

9. Measurement 56


10. Soil 66

11. Force and Energy 73

12. Air and Water 81

13. Earth, Sun and Moon 88

14. Light and Shadows 96

15. Natural Disasters 102


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Specific learning objectives

Aft er the completion of this chapter, the students will be able to: • appreciatetheimportanceofplantsinourlife • describetheprocessofgrowingplantsfromseeds • grownewplantsfromroots,stems,leavesandspores • identifyvariousagentsofseeddispersalinoursurroundings • explainthemeaningandimportanceofcropsandagriculture

Materials Required

Garden soil, water, plant pots, seeds, etc.

Warm Up

Th eteachermaybeginthetopicbyaskingquestionslike,whatdowegetfromplants;howdowegetfreshairtobreathe;doyougotoplayinthegardenorformorningwalk,etc.Tellthestudentsaboutthevariouswaysinwhichplantsareusefulforus.Later,askthemtocompletetheexercisegivenintheDelphi’sCornersection.

Concept Explanation

• Growing plants from seeds: Ask students to bring bean seeds soaked overnight,wrappedinamuslinclothtotheclass.Askthemtostudythepartsoftheseedanddrawadiagramintheirnotebooks.Askthemtolabelthepartsoftheseed.Explaintothemaboutthevariouspartsoftheseeds.

• Seed germination: Tellstudentswhyplantsproducealargenumberofseeds.Givethemtimetosoakgramseedsforadayinwater.Letthemthenstoretheseedsinamoistclothorcotton.Makethemstudythewayseedsgerminate.Discussthestagesofgerminationofseeds.Alsoaskthemtolistthenecessaryconditionsforgermination.Performtheexperimentonconditionsrequiredforseedgermination.

• Seed dispersal: Talk to students about how seeds get dispersed from one place toanother.Giveexamplesofthemodesofseeddispersal.Tellthemwhyseeddispersalisimportant.Giveexamplesofseedsdispersedbywind,water,animalsandfruitexplosionwith reasons for the same.

• Growing new plants from other plant parts:Askstudentstobringcarrot,potato,etc.toclass.Showthemthatcarrotisactuallyaroot.Showtheeyesofthepotatoandexplaintothemthatpotatoisastem.Givemoresuchexamplestoexplainthatnewplantscanalsogrowfromotherplantparts.

CHAPTER 1Growing Plants

6

• Agriculture and crops: Studentscanbetakentoafarmforanexposuretoagriculturalpractices.Avideoonfarmingcanalsobeshowntostudentsinclass.Discussthestepsoffarmingwiththehelpofavideoorfieldvisitarrangedbyyou.

Reinforce

Helpthestudentsdeveloptheskill/value(researchandthinking)givenintheLifeSkillssectionofthechapter.Discussthetaskgiveninthesectionandaskthemtodothetaskgiven.Also,makethemunderstandtheimportanceoftheseskillsintheirlives.Discusstheimportanttermsandtheirmeaningsgiveninthechapter.Askthemtocompletetheexercisesgivenattheendofthechapter.Discusstheanswersintheclass.

Explore

AskstudentstocompletetheFunTimeandProjectgivenattheendofeachchapter.

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1. Identify the following stages of agriculture. (a) (b)

(c) (d)

(e)

WORKSHEET 1

2. Name the plant part by which the following plants grow. (a)Bryophyllum

(b)Beetroot

(c)Sugarcane

(d)Tomato

(e)Moneyplant

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1. Briefl y explain the following stages of seed germination.

Warmth

Soil

Water in soil

Roots

Shoot

Air

Leaf

2. State the mode of seed dispersal in the following plants.

(a)Poppy

(b)Xanthium

(c)Coconut

(d)Dandelion

(e)Speargrass

WORKSHEET 2

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Answers to Coursebook

A. 1. (a) Cotyledon (b) Rabicrops (c) Kharifcrops (d) Seeddispersal (e) Moneyplant 2. (a) T (b) F (c) T (d) F (e) FB. 1. (a) Th epracticeofgrowingplantsonalargescaleforfoodandotherpurposes. (b) Plantsofthesamekindthataregrownonalargeareaoveraperiodoftime. (c) Growingofcropsonthestepscutalongthemountainslope. (d) Th eprocessofgrowingofanewtinyplantfromaseedinthepresenceofthe

rightamountofair,waterandsunlight. 2. Type of crop Rabi crops Kharif crops

Duration FromNovembertoApril FromJunetoOctober

Characteristicfeature

Donotdependonmonsoons Depend largely onmonsoons

Examples Wheat,legumes,gram,beans Rice,maize,jowar, bajra

3. Th eharvestedgrainsarestoredinsealedair-tightsacsorcontainerssothattheydonotgetspoiledbymoistureandanimals.

4. (a) Stem (b) Root (c) Leaf (d) Stem 5. Seedcoat,cotyledons(seedleaves)andbabyplantC. 1. Somewaysinwhichseeddispersaltakesplaceareasfollows. • Wind: Someplantshavelight-weight,hairyandwingedseeds.Th esecanbeeasily

carriedbywind.Examplesofsuchseedsaresycamore,dandelion,madar, etc. • Water: Some plants have spongy seedswhich can float on the surface ofwater.

Suchseedsmayhaveafibrouscoveringtoowhichishelpfulinkeepingthemafloat.Watercurrentscarrytheseseedstolargedistances,sometimesseveralkilometres.Forexample,lotushasaspongyseedwhilecoconuthasafibrousoutercoveringonthe seed.

• Animals: Animalseatfruitsandthrowawaytheseeds.Th eseseedsgetdispersedtodifferent locations.Seedswhichareeatenupwiththe fruitbysomebirdsandanimalsarereleasedoutintheirdroppingsorfaeces.Someseedshavehooks,spinesorhairwhichclingtothebodyhairoftheanimalsandgetcarriedawayfromtheirparentplant.Forexample,xanthiumseedhashair,whilespeargrassandcockleburhavespines.

• Fruit explosion: Poppy,peaandbeanfruitsburstopenonripening.Th edryseedsgetscatteredinalldirectionsawayfromtheparentplant.

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2.

Fieldsareploughedwiththe help of tractors

Seeds are sown Th ecropsareirrigated.

Oncegrown,thecropsareharvested.

Forprotectingcropsfrominsectsandpests, insecticides and pesticides are

sprayedinthefields.

3. Roots:Rootsof certainplants such as carrots, radish, beetroot and sweetpotatocangrowintoanewplant.Ifthetopportionofacarrotiscut(thethickerportionofcarrotswhichhasleavesattheend)andimmersedinwaterinaglassandkeptinsunlightforafewdays,newplantwillgrowoutofit.

Leaves:Leavesofsomeplantscanbeusedtoproduceanewplant.Forexample,ifa Bryophyllum leaf iskept inthemoistsoil forafewdays,youngplantswillstartgrowingoutfromtheedgesoftheleaf.

Stem:Stemcuttingsofrose,hibiscus,moneyplant,sugarcane,etc.areusedtogrownewplants.Th estemcuttingisplantedinthesoilandanewplantgrowsinafewdays.

Undergroundstemssuchaspotato,ginger,onion,etc.cangrowintoacompletelynewplant.Th epotatostemcontainsbudscalled‘eyes’onitssurface.Whenaportionofthisstemcontaininganeyeisplantedinthesoil,newplantarisesfromtheeye.Similarly,ifanonionisplantedinthesoilandwateredregularly,newplantwillgrowfrom it.

4. Th eseedsaredispersedtodifferentplacesawayfromtheparentplantthroughtheprocessknownasseed dispersal.

Th eplantsarefixedatoneplaceandcannotmovefromplacetoplacetodispersetheirseeds.Ifsomanyseedsgrowtooclosetoeachother,thennoneofthemwillgetsufficientwaterandfoodfromthesoil.Alsoplantsgrowingtooclosetoeachotherwillnotgetsufficientsunlightandspaceforgrowth.Asaresult,healthyplantswillnotgrow.Th us,itisimportantthatseedsaredispersedatadistancefromthe

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parentplantsothatmostofthemgetenoughwater,food,space,airandsunlightforgrowth.

5. Th eseedswhichgetrightamountofair,waterandsunlightproduceaseedling or ababyplant.Th eprocessofdevelopmentofaseedintoaseedlingisknownasseed germination.

Ababyplantinsidetheseedgetsfoodfromtheseedleaves.Butwhenthisstoredfoodisusedup,thebabyplantneedsfoodfromoutside.Atthisstage,soilplaysanimportantroleintheseedgrowth.Th erootsoftheseedlingabsorbfoodandwaterfromthesoil.Th eairwhichispresentinthesoilporesisalsousedbytheseedling.Watermakestheseedcoatsoftandbabyplanteasilybreaksthroughit.Gradually,theseedlingdevelopsleavesandgrowsintoanewplant.

D. 2 4 1 5 3 6E. 1. Allseedsneedenoughspacetogerminateintoplants.Ifthereislessspace,theywill

notgerminateintohealthyplants.Th us,farmersleavespacebetweenseeds. 2. Seedwillnotgerminateasitrequiresenoughairtogerminatealongwithsunlight,

soil and water. 3. Harvestedgrainsshouldbekeptinair-tightcontainerssothatthereisnomoisture

aroundthem.Th eyshouldbeprotectedfrominsects,ratsandflies.

Answers to Worksheets

Worksheet 1

1. (a)Ploughing (b) Irrigation

(c) Harvesting (d) Sprayinginsecticides

2. (a) Leaf (b) Root (c)Stem

(d) Stem (e) StemWorksheet 2

1. Th eseedgetsair,waterandwarmthandanewplantemerges.Th enewplantdevelopsrootsandashoot.Th eshootthendevelopsleaves.

2. (a)Fruitexplosion (b) Animals (c) Water

(d)Wind (e) Animals

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Aft er the completion of this chapter, the students will be able to: • listthevariouscomponentsoffoodandstatetheirsignificance • explaintheimportanceofabalanceddiet • distinguishbetweencommunicableandnon-communicablediseases • discussthesignificanceofvaccinationforchildren

Materials Required

Differenttypesoffood,vaccinationchart

Warm Up

Beginthetopicbyfindingoutthefavouritefoodsofchildren,theirparentsandfriends.Tellthemthatchildrenoftheirageneedfoodtogrowupandtofightdiseases.Th eeldersneedfoodforenergytowork,whileoldpeopleneedlessenergy.Talkaboutenergy-richfoods,diseasefightingfoods,etc.AskthestudentstocompletetheexercisegivenintheDelphi’sCornersectionofthechapter.

Concept Explanation

• Food and its components:Discusstheenergygiving,bodybuildingfoodsandprotectivefoods.Giveampleexamplesofeachtypeoffood.Askchildrentomakeascrapbookonfoodsrichindifferenttypesofcomponents.Includewaterandroughagealsoinyourdiscussion.

• Balanced diet:Findoutfromthestudentswhattypeoffoodisofteneatenbythem.Askthemwhattheyhadfordinnerlastnightandtellthemtowritethat.Askthemtostate which food components were in their diet. Tell them about a balanced diet and its importance in our life.

• Staying healthy:Discussinclassthatbeinghealthyisnotjustbeingfreeofdiseases,butitalsomeansbeingfitandcheerfultoleadahappylife.Discusstheimportanceofwalk,play,exercise,restandproperfoodforstayinghealthy.

• Diseases:Talkaboutdiseasesandtheirtypes.Useoftheblackboardasateachingaidbecomesimportanthere.Classifythediseasesascommunicableandnon-communicablediseases.Discussaboutdeficiencydiseaseswhichoccurduetothe deficiencyofcertaincomponentsinfood.Alsotalkaboutthediseasesthatoccurduetoexcessiveintakeofcertaincomponents.Stressuponeatingabalanceddietalways.

CHAPTER 2Food and Health

13

Moveontocommunicablediseasesandtalkabouttheuseofhandkerchief,handwash,etc.toavoidthe spread of communicable diseases. A small discussion on ‘Swachh Bharat Abhiyaan’canalsobetakenup.

• Prevention of communicable diseases: Discuss the ways in which spread ofcommunicablediseasescanbeprevented.Askstudentstocomeupwiththeirsuggestionsbywhichcommunicablediseasescanbeprevented.Talkabouthandwash,hygieneand cleanliness.

Discussaboutvaccinesandtheiradministeringtoinfants.Avaccinationchartcanbeused.AlsotalkaboutthePulsePolioCampaignheldinIndia.

Reinforce


Explore


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1. Complete the table.

Nutrients Functions Examples

(a)Carbohydrates Rice, potatoes, sweetpotatoes, breads, etc.

(b)Fats

(c)Proteins

(d)

Th ese are called protectivefoods as they protect usagainstinfectionsandhelpustofightdiseases.

Fruitsandvegetables

(e)Minerals Green leafy vegetables,fruits,milk,etc.

2. What do you mean by a balanced diet? _______________________________________________________

3. List the functions and sources of roughage in our diet. _______________________________________________________

_______________________________________________________

WORKSHEET 1

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WORKSHEET 2


Disease Caused by the defi ciency of Symptoms

(a)Night blindness

(b) VitaminB

(c)Scurvy

(d)Rickets

(e) Iron

(f)Goitre

2. Write any fi ve healthy habits. _______________________________________________________

_______________________________________________________

_______________________________________________________

_______________________________________________________

_______________________________________________________

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A. 1. (a) Anaemia (b) Scurvy (c) Weakbones (d) Goitre (e) Rickets 2. (a) nightblindness (b) pasteurised (c) deficiency (d) communicableB. 1. Roughagehelpsinthedigestionoffood.Itpreventsconstipationandalsohelpsin

bowelmovements.Itkeepsourdigestivesystemhealthy. 2. Communicablediseasesspreadfrompersontopersonthroughcontactandvectors.

Non-communicablediseasesdonotspreadfrompersontoperson.Th eyoccurduetothedeficiencyorexcessofnutrientsinthebody.

3. (a) Malnutrition: A physical state of a person which results due to the lack ofnutrientsinthebody.

(b) Disease:Astateinwhichourbodyisnolongerinahealthycondition. (c) Vaccination:Th eprocessofgivingvaccinestoprotectpeoplefromdiseases. (d) Balanced diet: A diet that contains all nutrients in sufficient quantities for

healthyfunctioningofthebody. 4. Carbohydrates are called energy-giving components of the food as they provide

energytothebodytoworkandplay. 5. •Waterhelpsinthedigestionoffood. • Wateractsasamediuminvariouschemicalreactionsthatoccurinthebody. • Waterhelpsintheexcretionofbodywastesintheformofurineandsweat. • Watermaintainsthebodytemperature. • Waterisimportanttokeepourbodyhydrated.C. 1.

Nutrients Functions Examples Carbohydrates Th eseareknownasenergygivingfoods.

Th eyprovideuswithenergy.Rice,potatoes,sweetpota-toes, breads, etc.

Fats Fatsprovideuswithmuchmoreenergythancarbohydrates.Fatsarestoredinthebodytoprovideinsulationfromexternalcold.

Ghee, oil, butter, cheese, cream,nutsanddryfruits,etc.

Proteins Th eseareknownasthebodybuildingfoods.Proteinsareimportantforgrowthofthehumanbody.Th esealsohelpintherepair of worn out cells and tissues.

Pulses,soyabean,milk,eggs,fish,cheese,meat,etc.

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Vitamins Thesearecalledprotectivefoodsastheyprotectusagainstinfectionsandhelptofightdiseases.

Fruitsandvegetables

Minerals Thesearemainlyneededforthedevel-opmentofbonesandteeth.Theyarealsoinvolvedinmakingredbloodcellsinthehumanbody.

Greenleafyvegetables,fruits,milk,etc.

2. Thespreadofcommunicablediseasescanbepreventedifwefollowsimplehealthyhabits.

• Thehousesshouldbekeptclean,wellventilatedandfreeofmosquitoes.Thereshouldbesufficientsunlightenteringthehouse.Oneshouldalsokeepmattresses,sofacoversandblanketsinthesunlightregularlytodisinfectthem.

• Watershouldbeboiledandkeptcovered.Foodshouldalsobekeptcovered.Oneshouldnoteatstalefood.Nofliesshouldbeallowedtositonthefooditemsastheycarrygermsofvariousdiseases.

• Invillages,waterinthewellsshouldbechlorinatedregularly. • Mosquitoes should not be allowed to breed in and around the houses.Water

shouldnotbeallowedtostagnateasmosquitoeslayeggsinthestandingwater. • Kitchens should be kept clean and free of cockroaches and insects. Similarly,

bathroomsandtoiletsshouldbekeptcleananddisinfectedregularly. 3. Apersonwhosuffersfromthelackofnutrientsinhis/herdietoveralongperiodof

time is said to be in a state of malnutrition. Thedeficiencydiseasescanbecuredbytakingdietrichinspecificnutrientsregularly.

Excessofanutrientsisalsobadforhealth.Forexample,excessiveintakeoffatsinthedietmaymakeoneobese.Thus,itisimportantforapersontoeatahealthydiettostayhealthy.

4. The communicable diseases are the ones which get transmitted from person toperson.Thecommunicablediseasesspreadthroughgerms.Thesegermsenterintothebodyofahealthypersonduringbreathing,throughinfectedfoodorwaterorthroughcutsintheskin.

The communicable diseases may spread from person to person through air(coughingsneezing,etc.),water(drinkingcontaminatedwater),vector(mosquitobites).

D. 1. Measles 2. Communicable 3. Itspreadsthroughairorcontact.E. 1. Rahulgotinfectedduetocontaminatedfoodandwassufferingfromcholera. 2. Sheshouldavoideatingfat-richfoods.

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3. Proteinsaregrowthnutrients.Th eyareneededbygrowingchildrenso that theygrowwell.

4. A labourer needs energy to work hard for the whole day. So, he should eat anenergy-richdiet.


Worksheet 1 1. (a)Carbohydrates:Th eygiveenergy. (b)Fats:Th eygivemoreenergycomparedtocarbohydrates.Ghee, oil and butter are

examplesoffats. (c)Proteins:Th eyareresponsibleforgrowth.Pulses,eggs,milkandfishareexamples

ofprotein-richfood. (d)Vitamins (e)Minerals:Th eyprotectusagainstinfectionsandhelptofightdiseases. 2. Adietthatcontainsadequateamountofdifferentcomponentsoffoodforthehealthy

functioningofourbodyiscalledabalanceddiet. 3. Roughage:Itisfoundinpulses,cerealsandleafyvegetables.Itaddsbulktothefood

andhelpsindigestion.Itpreventsconstipationandalsohelpsinbowelmovements.Worksheet 2 1. (a)VitaminA:Inabilitytoseeclearlyindimlight (b)Beri-beri:Problemindigestion (c)VitaminC:Bleedingandswollengums (d)VitaminD:Softeningandbendingofbones (e)Anaemia:Weakness,lethargy,darkcirclesaroundeyes (f)Iodine:Unhealthyteeth,weakbones 3. • Weshouldeatabalanceddiet. • Weshouldexerciseregularlytostayfitandforproperbloodcirculation.Yogais

alsorecommendedforhealthyliving. • We must maintain a proper posture while sitting, standing, walking and even

sleeping. • Weshouldtakesufficientrestasitrejuvenatesourmindandrepairsourbody. • Weshouldgoformorningwalkandeveningwalkregularly.

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Aft er the completion of this chapter, the students will be able to: • defineahabitat • listthecharacteristicsofdifferenttypesofhabitats • discussadaptivefeaturesofanimalsindifferenthabitats

Materials Required

Picturechartofforest,desert,mountains,etc.alongwiththeanimalslivingthere;movieclipsofdifferenttypesofhabitats

Warm Up

Tellthestudentsaboutdifferentbirdswhichmigratefromoneplacetoanotherinwinters.Ask themif theyhaveseenanymigratorybirds.Discusshowanimalssurvive thebestin favourable conditions.Also talk about different types of places on the earthwheredifferenttypesofanimalslive.Th enaskthemtocompletethetaskgivenintheDelphi’sCornersection.

Concept Explanation

• Habitat:Askstudentstolocatedifferentanimalsintheirsurroundings.Tellthemthatanimalsliveinthesurroundingsorplaceswhicharethemostsuitableforthem.Th eyprovideenoughfoodandproperclimateforthepropersurvivaloftheanimals.Definehabitatafterthisdiscussion.Movieclipsofdifferenttypesofhabitatsacrosstheworldcanbeusedtoexplaindifferenttypesoflivingconditionsthatprevailintheworld.Tomake thediscussionmore interesting, studentsmaybeaskedtodrawtheir favouritehabitats.

• Adaptation in animals:Continuethediscussiononhabitatandproceedtothetypesofanimalsthatliveindifferenthabitats.Giveexamplesandencouragestudentstoidentifythefeatureswhichhelpthemtoadapttotheirsurroundings.

Discussaboutthemovementsofdifferenttypesofanimalslivingindifferenthabitats.Bodycoveringssuchasfur,feathers,scales,shellandcuticlecanbediscussedwiththepicturesofanimalsthathavethese.Talkaboutdifferentorgansofbreathinginanimalsofdifferenthabitats.Alsotellthestudentsaboutmigrationindifferentanimals.

CHAPTER 3Animals: Habitat and Adaptation

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Reinforce


Explore


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1. State the body coverings in the following animals.

(a) (b)

__________________ __________________ (c) (d)

__________________ __________________ (e) (f)

__________________ __________________ Also state why the animals have diff erent types of body coverings. _______________________________________________________

2. Defi ne habitat. _______________________________________________________

3. List the adaptations of birds which help them to fl y. _______________________________________________________

WORKSHEET 1

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1. Name the breathing organs of the following.

(a) (b)

__________________ __________________ (c) (d)

__________________ __________________ (e) (f)

__________________ __________________


Name ofhabitat Forest Desert Mountain polar regions Ocean

Animal(1)

Features(2)

WORKSHEET 2

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A. 1. (a) migration (b) cold,rocky (c) skin,lungs (d) polar 2. (a) Spiracles (b) Blowholes (c) Lungs (d) Moistskin (e) Gills (f) LungsandskinB. 1 (a) Fur–Polarbear (b) Scales–Fish (c) Shell–Turtle (d) Cuticle–Insects 2. Fishswimswiththehelpofitsfins.Th etailfinhelpsthefishtochangedirections

whileswimming.Th efinsofthefishhelpittomoveforwardinwater. 3. Th e mass movement of animals over large distances in search of favourable

conditionsiscalledmigration.SiberiancranemigratesfromSiberiatoIndiaeveryyearinwinters.

4. Frogsbreathewiththehelpoftheirlungsonlandandwithmoistskininwater. 5. Th eadaptivefeaturesofbirdsareasfollows. • Th ebirdshavelightandstrongflightmuscles. • Th ebonesarehollowsothatthebirdcankeepafloatinair. • Th eupperlimbsaremodifiedtoformwings. • Th ebodyofbirdsiscoveredwithfeatherswhichkeepthebirdswarm. 6. Characteristicfeaturesofadesertareasfollows. • Desertisadryandhotplace. • Th etemperatureishighandrainfallislimited. • Soilcontainsmainlysandinwhichlimitedvegetationoccurs. • Animalssuchascamels,rats,snakesandplantssuchascactus,babool,etc.are

found in deserts.C. 1. • Animalssuchasearthwormsbreathewiththehelpoftheirskin.Frogsbreathe

throughtheirlungsaswellasskin. • Fishhavegillstobreathe. • Insectsbreathewiththehelpoftheirspiracles. • Whalesanddolphinshaveblowholestobreathe. • Humanbeingsandmanyanimalsbreathewiththehelpoflungs. 2. • Animalslivingincoldregionshavefurontheirbody,suchaspolarbear. • Animalslikefishandsnakeshavescalesontheirbody. • Turtles,tortoisesandsnailshaveshellovertheirbodies. • Insectssuchasbeetleshavecuticleontheirbody. • Birdshavefeathersontheirbodywhichkeepthemwarm. 3. Ahabitatisanaturaldwellingplaceofanorganism.Itprovidesproperfood,shelter

andprotectiontotheorganism.Typesofhabitatareasfollows.

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• Forest:Ithasgrasses,treesandfertilesoil.Th elandundertreesreceiveslimitedsunlight.Animalssuchasdeer,elephant,lionliveinforests.

• Desert:Desertisadry,sandyandhotplacethatreceiveslimitedsunlight.Itis hotduringthedayandcoldduringthenight.Camelsliveindesert. •Mountain: Th esearehillyregionswithcoldclimateandrockysurface.Snowfall occursinwinters.Snowleopard,yakandmountaingoatarecommonhere. 4. Animalsmovefromoneplacetoanotherinsearchoffood,favourableconditions

and protection from enemies. D. Fishhasastreamlinedbody.Th ishelpsittocutthroughwatereasily. • Th etailfinhelpsthefishtochangedirectionswhileswimming.Th efinsofthefish

helpittomoveforwardinwater. • Afishhasgillswhichhelpittobreatheinwater.Itinhalestheoxygendissolvedin

water.E. 1. Afishbreathesthroughgills.Gillstakeinoxygendissolvedinwater. 2. Tadpolesareaquaticcreaturesthatcanonlybreatheandsurviveinwater.So,they

breathethroughgills. 3. Unlikebirds,thewingsofinsectsarethinanddonothavemusclesattachedtothem

tobringaboutmovements.Th eymoveusingthemuscleswhicharefoundinsidethechest of the insect.


Worksheet 1 1. (a) Fur (b) Scales (c) Scales (d)Shell (e) Cuticle (f) Feathers Th ecoveringoftheirbodydependsuponthetypeofhabitattheanimalslivein. 2. Habitatisthenaturaldwellingplaceofanorganism. 3. Birds flywith the help of wings. Birds have hollow streamlined bodies, bones and

strongflightmuscleswhichhelptheminflying.Worksheet 2 1. (a) Lungsonlandandskininwater (b) Gills (c) Lungs(d) Blowholes(e) Spiracles (f) Lungs 2. Forest:Lion;Lotsoftreesandfertilesoil Desert:Camel;Dryandreceivesverylittlerainfall Mountain:Snowleopard;Rockysurfaceandcoldclimate PolarRegions:Polarbear;Extremelycoldanddry Ocean:Whale;Deepandsaltywater

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Aft er the completion of this chapter, the students will be able to: • describetheimportanceofskeletalsysteminourbody • identifydifferentbonesandjointsinthebody • preparemodelsofjointsandexplaintheirfunctioning • appreciatethesignificanceofwell-developedmuscles

Materials Required

Humanskeleton,modelsofjointsofdifferenttypes.

Warm Up

Askthestudentsabouttheirfavouriteoutdoorsports.Askthemwhydotheyplay.Whatistheimportanceofplayingandexercisinginlife?Tellthemthatplayingandexercisingareasimportantaseatingfoodanddrinkingwater.Oneshouldplayandexerciseregularlytokeephis/herbonesandmuscleshealthyandfit.Now,askthemtocompletethetaskgivenintheDelphi’sCornersectionofthechapter.

Concept Explanation

• Skeletal system:Introducetheskeletontotheclassanddiscussitsuses.Amodelofaskeletoncanbeusedintheclasstoexplainthearrangementofbonesindifferentskeletalpartssuchasribcage,skull,etc.Explainthefunctionofeachpartseparately.Talkaboutbone health and importance of nutritious food.

• Cartilage:Discusshowbonesarepreventedfromgettingdamagedbyrubbingagainsteachother.Pointtothemodeloftheskeletonwherecartilagearelocated.

• Joints:Pointtothetypeofjointsintheskeleton.Askstudentstoidentifythetypesofjointsintheirknees,elbows,shouldersandneck.Explainhowdifferenttypesofjointsallowthemovementsofbonesaboutthemselves.

• Muscles:Discusshowmusclesmakethemovementofbonespossible.Statethetypesandfunctionsofdifferenttypesofmuscles.Ashortquizmayalsobeconductedintheclassafterthecompletionofthisdiscussion.Tellthemhowmusclesbecomestrongwithregularexercise.

Reinforce

Helpthestudentsdeveloptheskill/value(researchandthinking)givenintheLifeSkillssectionofthechapter.Discussthetaskgiveninthesectionandaskthemtodothetask

CHAPTER 4Bones and Muscles

26

given.Also,makethemunderstandtheimportanceoftheseskillsintheirlives.Discusstheimportanttermsandtheirmeaningsgiveninthechapter.Askthemtocompletetheexercisesgivenattheendofthechapter.Discusstheanswersintheclass.

Explore


27

1. Tick () the correct option.

(a)Th ecardiacmuscleshaveastructurelikethatofvoluntary/involuntary musclesbuttheyfunctionlikevoluntary/involuntary muscles.

(b)Musclesareattachedtobonesbyfibre-likestructurescalledtendons/ligaments.

(c)Th eshoulderjointisaball-and-socket/hingejoint.

(d)Th elongestboneinthebodyisbackbone/femur.

(e)Twobonesmeeteachotheratmuscles/joints.

2. Label the parts in the skeleton.

(a)_____________

(b)_____________(c)_____________

(d)_____________

(e)_____________

WORKSHEET 1

28

1. Give one word answer for the following.

(a)Th eframeworkofbonesinthebody. ___________

(b)Alongbreastbonewhichholdstheribs. ___________

(c)Th eelasticandhardtissuewhichprotectsthebonesatjoints.

___________

(d)Th epointsatwhichbonesarejoinedtogether. ___________

(e)Strongandflexibletissueswhichholdthebonesatthejoints.

___________

2. Name the type of joint at the following body parts.

(a)Shoulder _____________________

(b)Neck _____________________

(c)Wrist _____________________

(d)Elbow _____________________

(e)skull _____________________

3. Write the function of each of the following.

(a)Ribcage _________________________________________

(b)Backbone _________________________________________

(c)Limbs _________________________________________

(d)Skull _________________________________________

WORKSHEET 2

29


A. 1. (a) T (b) T (c) F

(d) T (e) T

2. Ball-and-socketjoint—hipjoint,Hingejoint—Elbowjoint,

Pivotjoint—Betweenskullandfirsttwovertebrae,Glidingjoint—Wristandankle,

Immovablejoint—Bonesofskull

B. 1. (a) Pivot joint: Th epivotjointisfoundbetweenthefirstandsecondvertebraeinthebackbone.Th isjointhelpsinthemovementoftheheadupwards,downwardsandsideways.

Gliding joint : Th etypeofjointwhichallowsthebonestoglideovereachotheriscalledglidingjoint.Itisfoundin

(b) Th e jointswhich allowmovement about themaremovable joints.Th e jointswhichdonotallowanymovementaboutthemareimmovable.

(c) Voluntary muscles:Th emuscleswhichareattachedtotheskeletonandwhosefunctionisunderourcontrolarecalledvoluntarymuscles.

Involuntary muscles:Th emuscleswhicharenotattachedtotheskeletonandwhosefunctionisnotunderourcontrolarecalledinvoluntarymuscles.

2. Th eskeletongivesshapeandsupporttothebody.Itprotectsourinternalorgans.Itallowsthemovementofdifferentbodyparts.Somehollowbonescontainbonemarrow where blood is manufactured.

3. Inadditiontobones,ourskeletalsystemalsohasatoughbutelasticsubstancecalledthecartilage.Th emainfunctionofthecartilageistoholdthebonesintheirplace.Italsoprotectsthebonesattheirjoints.Th eboneswouldotherwiserubagainsteachotherandgetdamaged.Cartilagealsoformsourearpinnaandthefrontpartofthenose.

4. Th emuscleswhosestructureislikevoluntarymusclesandfunctionisinvoluntaryarefoundintheheart.Th esearecalledcardiacmuscles.Th esecontractandrelaxtopumpbloodinourbody.Th eseworkthroughoutthelifeofanindividualwithoutanyfatigue.

C. 1. Whenonemusclecontracts, itbecomesshorterandpullsthebonetowhichit isattached.Atthesametime,theothermusclerelaxesandbecomeslonger.Whenthe

30

movementisreversed,theformermusclerelaxesandthelattercontracts.Thus,thepairedactionoftwomusclescausesthemovementofaboneinonedirection.

2. Limbs:Therearetwopairsoflimbsinourskeleton—theforelimbs(arms)andthehindlimbs(legs).Theselimbsarejoinedtothespinewiththehelpoftheshouldergirdleandthepelvicgirdle,respectively.Thelongbonesarehollowandarefilledwith a substance called bone marrow. The blood is manufactured in the bone marrow.

Ribcage:Thebonesaroundthechestarecalledribs.Theribcageenclosessomevitalinternalorgansincludingheartandlungs.Thereare12pairsofribsinourribcage.Alongbreastbonecalledsternumholdstheribsintheirplaceatoneside.Theotherendsoftheribsareattachedtothebackbone.Thelowesttworibsarenotattachedtothesternum.Thesearecalledfloatingribs.Theseareattachedonlytothebackbone.

3. Thereareanumberofjointsinourskeleton.Theseareoffollowingtypes. Ball-and-socket joint: Thetypeofjointinwhichoneboneendsataballandfitsinto

thesocketshapedotherbone.Insuchjoints,thebonesshowmaximummovementabouteachother.Theshoulderjointisaball-and-socketjoint.Anothersuchjointinourbodyisthehipjoint.

Hinge joint: Asthenamesuggests,thistypeofjointworkslikehingesinthedoor.Thismeansthebonescanmoveabouteachotherinonedirectiononly.Forexample,theelbowjoints,kneejoints,fingersandtoes,allhavehingejoints.

Pivot joint: Thepivotjointisfoundbetweenthefirstandthesecondvertebraeinthebackbone.Thisjointhelpsinthemovementoftheheadupwards,downwardsandsideways.

Gliding joint: Thetypeofjointwhichallowsthebonestoglideovereachotheriscalledglidingjoint.Itisfoundinthewristandankle.

4. (a) Itconsistsof22bones.Thebonesinaskullareinterlocked.Theycannotmoveexceptthelowerjaw.Weeat,talk,singandcheeronlywhenthelowerjawmoves.

Eightbonesintheskullprotectthebrain.Fourteenotherbonesformthefacialbones.

(b) Thebackboneorthespineisoneofthemostimportantpartsoftheskeleton.Itisattachedtotheskull.Itsmainfunctionistoprotectthespinalcordofthebody.Ifyoubendandrunyourhandalongyourback,youcanfeelyourbackbone.

(c) The bones around the chest are called ribs.The ribcage encloses some vitalinternalorgansincludingheartandlungs.

(d) There are two pairs of limbs in our skeleton—the forelimbs (arms) and thehindlimbs(legs).Theselimbsarejoinedtothespinewiththehelpoftheshoulder

31

girdleandthepelvicgirdle,respectively.Th elongbonesarehollowandarefilledwith a substance called bone marrow. Th e blood is manufactured in the bone marrow.

(e) Th ebonesareheldtogetheratthejointswiththehelpofstrongstructuresortissuescalledligaments.

(f) Inadditiontobones,ourskeletalsystemalsohasatoughbutelasticsubstancecalledthecartilage.Th emainfunctionofthecartilageistoholdthebonesintheirplace.Italsoprotectsthebonesattheirjoints.Th eboneswouldrubagainsteachotherandgetdamaged.

D. Neck—Pivotjoint Shoulder—Ball-and-socketjoint Elbow—Hingejoint Wrist—Glidingjoint Hip—Ball-and-socketjoint Knee—HingejointE. 1. If thebackbonedidnothavevertebrae, itwouldhavebeenonestraight rod.We

wouldbestraightandunabletobend. 2. No,musclescontractandrelax.Th eyareattachedtothebonesandcausemovements

ofthebody. 3. Wewouldnotbeabletoopenourmouthforchewingfood,eatingfood,talking,etc.


Worksheet 1 1. (a) voluntary,involuntary (b) tendons (c) ball-and-socket (d) femur (e) joints 2. (a) Skull (b) Ribcage (c) Forelimb (d) Backbone (e) HindlimbWorksheet 2 1. (a) Skeleton (b) Sternum (c) Cartilage (d) Joints (e) Ligament 2. (a) Ball-and-socketjoint (b) Pivotjoint (c) Glidingjoint (d)Hingejoint (e) Fixedjoint 3. (a) Itprotectstheheartandthelungs. (b) Itprotectsthespinalcord. (c) Ithelpstodoactivitieslikegraspingobjectsandmovement. (d) Itprotectsthebrain.

32


Aft er the completion of this chapter, the students will be able to: • appreciatetheimportanceofhumannervoussystem • listthefunctionsofbraininthebody • discusstheworkingofoursenseorgans • explainhowtotakecareofthesenseorgans

Materials Required

Diagramsofnervoussystem,brainandspinalcord

Warm Up

Slightlyrunafeatherorapaperthroughthehairofachild.Hewillmovehisheadaway.Askhimwhyhemovedhishead.Alsoaskwhichorganofthebodydirectsapersontoactinaparticularway.Telltheclassthatallouractionsandreactionsaredirectedbythenervoussystemofthebody.Evenwhenweareasleep,ourbrainhelpsinourheartbeat,breathingandbloodcirculation.NowaskthestudentstocompletethetaskgivenintheDelphi’sCorner section.

Concept Explanation

• Th e human nervous system:Use thediagramof thenervous system in class. Showhownervesfrombrainandspinalcordconnecttoeachandeverypartofthebody.Askstudentstolabelthebrain,thespinalcordandthenerves.

Now,switchtothediagramofthebrain.Labelitsparts.Explainthefunctionsofeachpart.Askstudentstorepeatthefunctionsofeachpartsothattheyareabletoremember.Askquestionstorecapitulate.Repeattheexerciseforspinalcordandnerves.Distinguishbetweendifferenttypesofnervesanddiscusstheimportanceofeach.

Toexplainthereflexactions,giveexamplesinclassbasedonstimulusandresponse.Askstudentstocomeupwiththeirexperiences.Drawreflexarcandmakestudentspractisethe same.

Reinforce

Helpthestudentsdeveloptheskill/value(researchandthinking)givenintheLifeSkillssectionofthechapter.Discussthetaskgiveninthesectionandaskthemtodothetaskgiven.Also,makethemunderstandtheimportanceoftheseskillsintheirlives.Discuss

CHAPTER 5Our Nervous System

33

theimportanttermsandtheirmeaningsgiveninthechapter.Askthemtocompletetheexercisesgivenattheendofthechapter.Discusstheanswersintheclass.

Explore


34

1. Label the main parts of the following system and name the system.

2. State the main functions of the parts labelled by you in Question 1.

(a) ________________________________________________

(b) ________________________________________________

(c) ________________________________________________

WORKSHEET 1

(d)_____________________

(a)____________

(b)____________

(c)____________

35

1. Complete the given fl ow chart.

Nervoussystem

(a)

(e) (f)(d)

(b) (c)

2. Write the functions of each part of the brain.

______________________________________________________

______________________________________________________

______________________________________________________

______________________________________________________

3. Write the names of diff erent types of nerves. Also, mention their functions.

______________________________________________________

______________________________________________________

______________________________________________________

______________________________________________________

WORKSHEET 2

36


A. 1. Nerve—CarriesmessagesCerebrum—Memory Medulla—controlsheartbeatsCerebellum—maintainsbodybalance 2. (a) Sensorynerve (b) Medulla (c) Cerebellum (d) Backbone (e) SpinalcordB. 1. Partsofnervoussystemarethebrain,nervesandthespinalcord. 2. Th e main function of the spinal cord is to transfer the information from the brain to

therestofthebody.Itcontrolsthereflexactions. 3. Th ebackbonesurroundsthespinalcordandprotectsit. 4. Th ebrainisthelargestandthemostimportantpartofthenervoussystem.Itcontrols

thewholebody.Itisthecentreforcontrolofallouractions,thoughts,feelingsandactivities.Itstoresinformationinthememory.Itreceivesandsendssignalsfromandtodifferentpartsofthebody,respectively.

C. 1. Cerebrum:Itisthelargestpartofthebrain.Itisresponsibleforthinking,learning,intelligence,memoryandlogic.Itcontrolstheworkingofoureyes,ears,noseandtongue.

Cerebellum: It isthepartofbrainlyingbelowthecerebrum.Itisresponsibleforthecontrolofourbodymovements.Itmaintainsthepostureandbalanceofthebody.

Brain stem/medulla: It remains active throughout the life without stopping.It controls the involuntary activities of our body such as heart beat, breathing,sneezing,swallowing,etc.

2. Someactionsperformedbyourbodyareasuddenandautomaticresponsetoanevent.Th eseactionsarecalledreflexactions.Th eseactionsareveryfast.Th emessageissentbythespinalcordonly.Th ebrainisnotinvolvedatallinreflexactions.Forexample,ifyousteponsomethingpointed,thensuddenlyyoumoveyourfootaway.Ifyouaccidentallytouchahotobject,thensuddenlyyouwithdrawyourhand.

3. Nervesareofthreemaintypes. • Sensory nerves:Th esensorynervespassthroughthespinalcord.Th esebring

messagefromthesenseorgansofthebodytothebrainortothespinalcord. • Motor nerves:Th emotornervescarrymessagesfromthebrainorspinalcord

todifferentpartsofthebody. • Mixed nerves:Mixednervesaretheoneswhichcarrymessagesfromthebrain

orspinalcordaswellasfromdifferentorganstobrainorspinalcord.D. 1. ReferFigure5.1onpage47.

37

2. Spinal cord: Th e main function of the spinal cord is to transfer the information fromthebraintotherestofthebody.Itcontrolsthereflexactions.

Brain:Th ebrainisthecentreforcontrolofallouractions,thoughts,feelingsandactivities.Itstoresinformationinthememory.Itreceivesandsendssignalsfromandtodifferentpartsofthebody,respectively.

Nerves:Th enervesare thosenumerous thread-likestructurespresent insideourbody.Th enervesconnectthebraintoallpartsofthebody.Th enervesconnectthebodypartstothebraindirectlyortothespinalcord.

E. 1. Th ebrainwouldsufferdamagesduetojerks.Itwouldcollidewiththeskullandgetaff ected.

2. Th e person will hardly survive as the heart beat and breathing control will bedestroyed.

3. Th ecerebrumcouldbeunderdevelopedorinjured.


Worksheet 1 1. (a) Brain (b) Nerves (c) Spinalcord 2. (a)Brainisthecontrolcentreofourbody.Itstoresinformationintheformofmemory.

Itreceivesandsendssignalstoandfromthedifferentpartsofthebody. (b)Nervescarrymessagesfromthevariousorganstothebrainorthespinalcordand

viceversa. (c)Spinalcordtransfersinformationfromthebraintotherestofthebody.Worksheet 2 1. (a)Brain (b) Spinalcord (c) Nerves (d)Cerebrum (e) Cerebellum (f) Medulla 2. Cerebrumisresponsibleforthinking,learning,intelligenceandmemory.Cerebellum

regulatesmuscularmovementsandcoordination.Medullacontrolsactivitiessuchasheartbeat,breathing,sneezingandswallowing.

3. Sensory nerves:Th eycarrymessage fromthevariousorgans to thebrainor to thespinal cord.

Motor nerves:Th eycarrymessagefromthebrainorthespinalcordtodifferentpartsofourbody.

Mixed nerves:Th eycarrymessagesfromthebrainorthespinalcordtodifferentorgansaswellasviceversa.

38


Aft er the completion of this chapter, the students will be able to: • identifythetrafficsignsandstatetheirmeanings • appreciatetheimportanceofroadsafety • discussthesignificanceoffiresafetyinoursurroundings • prepareafirstaidkitanduseitwhenneeded

Materials Required

Firstaidkit,visualclippingsonaccidentsandsafetyhabits,fireextinguisherWarm Up

Talktothestudentsaboutthetimetheygothurtandhow?Tellthemthataccidentshappenallofasudden.Wedonotexpectaccidents.Butwhenwearecareless,accidentsoccur.AskthemtocompletetheexercisegivenintheDelphi’sCornersection.

Concept Explanation

• Safety from fi re:Discuss inclass theusesoffire incookingfood,heating,etc.Th endiscussthehazardsoffire.Continuegivingexamplesofkitchenfire,electricalfireandotherdomesticfires.Tellthestudentsthatiffireisnothandledproperly,itcancausesevereharmto lifeandproperty.Discuss somesafety tipswhichshouldbe followedto prevent fire hazards.Th e teacher could also bring a fire extinguisher to class todemonstratefirefighting.Useofvisualclippingsonfireaccidentswouldprovetobemore impactful.

• First aid:Explaintothestudentsthataninjuredpersonorasickpersoncanbesavedbyprovidingsomeimmediatehelpbeforetheactualmedicalhelparrives.Th isiscalledfirstaid.Reinforcethediscussionbygivingexamplesofthetypeoffirstaidgivenindifferenttypesof injuries.Bringafirstaidboxtoclassandexplaintheuseof itscomponents.Encouragethestudentstomakeafirstaidboxfortheirhomestoo.

Reinforce


Explore


CHAPTER 6Safety and First Aid

39


(a)Aphysicalharmcausedtoabodypartduringanaccident. _____________

(b)Acollectionofmaterialsusedtoprovidefirstaidtotheneedy. _____________

(c)Adeviceusedtoputoutfires. _____________

(d)Aclinicalbandagemadeofsterilethread. _____________

(e)Athingmadetosupportafracturedhand. _____________

2. Tick () the right practices that you should follow for safety at home.

(a) (b)

(c) (d)

(e)

WORKSHEET 1

40

1. Write the steps to be taken in case of the following accidents.

(a)Forcutsandscratches

_______________________________________________________

_______________________________________________________

_______________________________________________________

(b)Forburns

_______________________________________________________

_______________________________________________________

_______________________________________________________

(a)Forfractures

_______________________________________________________

_______________________________________________________

_______________________________________________________

(a)Foranimalbite

_______________________________________________________

_______________________________________________________

_______________________________________________________

2. What are the components of a fi rst aid box?

_______________________________________________________

_______________________________________________________

WORKSHEET 2

41


A. 1. (a) fracture (b) firstaid (c) sprain (d) moved (e) vinegar/lemonjuice 2. (a) (iv) (b) (i) (c) (iv) (d) (iii) (e) (iv)B. 1. Firecancausesevereaccidents. Itmayburnarticles,buildings,peopleaswellas

vehicles. 2. Th eslinghelpstorestrictthemovementofthefracturedhandandsupportsit.One

shouldprepareaslingwiththehelpofacloth,andtiethroughtheneckiffracturehas occurred in hand.

3. Th eburningarticleiscoveredwithsandorathickblanket.Th iscutsthesupplyofairtotheobject.Th eobjectcannotburnintheabsenceofoxygenandthefireisputout.

4. Waterispouredontheburningobjectasitcoolsitdownandputsoutfire.Butoneshouldneverpourwateronfirecausedbyelectricaldefects. Itmaygiveasevereelectricshock.

5. Iffirehaseruptedinoil/petrol,neverusewatertoputitout.Oilislighterthanwaterandfloatsonit.Th us,firewillspreadfurther.Forelectricalfiresandfireinpetrol,sandshouldbepouredontheburningareainsteadofwater.

6. Th ewoundshouldbewashedthoroughlywithplentyofwaterandsoap.Antisepticcream should be applied and a bandage should be wrapped around the woundbeforetakingthepatienttothedoctor.

C. 1. Th eimmediatehelpandtreatmentgiventoaperson,whohasmetwithaninjuryoranaccident,beforehe/sheistakentothehospital,iscalledthefirstaid.

Intheeventofaburninjury,followingstepsshouldbetaken- • Lettheburntarearemainundercoldrunningwaterforsometime.Th isrelieves

pain. • Applysomeantisepticlotionontheburntareaandapproachadoctor. • Incasetheburnsaresevere,covertheburntareawithacleancottonorcloth

soakedinbakingsodasolution. • Th ewoundshouldbecoveredsothatdustandgermsdonotcauseanyinfection. • Ifblistersareformedontheburntarea,theyshouldnotbepricked. 2. Fireiscausedduetothefollowingreasons. (a) Kitchenfiresoccurduetoleakageofgasfromthegaspipeortheburner. (b) Electricalfirebreaksoutduetofaultinthewiringandoverloading.

42

(c) Domesticfiresmayoccurduetomishandlingofmatchsticks,carelessness,useofsyntheticclothesnearfire,etc.

Firehazardscanbepreventedinthefollowingways. •Electricalappliancesshouldbecheckedregularlyforanyfaults. •Neverwearsyntheticclotheswhilecooking. •Gaspipesshouldberegularlycheckedforany leakage.Doorsandwindows

shouldbeopenedincaseofaleakage. 3. Afire extinguisher is a special devicewhich is used toput outminorfires. It is

installedinschools,offices,hospitals,homes,etc.asasafetydevice.Ifafirebreaksout,thepinofthenozzleispulledoutandthechemicalissprayedontheburningobject. Itspreadsa layeronitandextinguishesthefire.Itcanbeusedincaseofelectricalfiresaswell.

4. Followingaresomewaystoputoutdifferenttypesoffire: • Theburningarticleiscoveredwithsandorathickblanket.Thiscutsthesupply

ofairtotheobject.Forexample,ifapersoncatchesfire,makehim/herrollonthegroundandcoverhim/herwithathickblanket.

• Waterispouredontheburningobjectasitcoolsitdownandputsoutfire. • Forelectricalfiresandfireinpetrol,sandshouldbepouredontheburningarea

instead of water. • Curtains,woodendoors,cushions,carpets, straw,paper,etc.are fuels forfire

tospreadfurther.Thus,oneshouldtaketheseobjectsawayfromtheburningobject.

D. 1. Fireextinguisher:Afireextinguisher isaspecialdevicewhich isusedtoputoutminorfire.Itisinstalledinschools,offices,hospitals,homes,etc.asasafetydevice.

E. 1. Asmokealarmissensitivetosmoke.Asthesmokerisesupandcomesincontactwithit,thealarmstartsringingandalertsthesurroundingpeople.Italsohelpstoinform further for help.

2. Theburntareaiskeptunderwaterforsometimeasitrelievespainandcalmsthepatient.

43


Worksheet 1 1. (a) Wound (b) Firstaidkit (c) Fireextinguisher (d)Gauzebandage (e) Sling 2. (a),(e)Worksheet 2 1. (a)Washthewoundthoroughlywithwaterandapplyanantisepticlotion. (b)Holdtheburntareaunderrunningwaterandapplyanantisepticlotionandconsult

a doctor. (c)Th efracturedareashouldnotbemoved.Givesupportbytyingaclothslingacross

theneckandthearmtopreventmovement.Takethepatienttothehospital. (d)Washthewoundthoroughlywithwaterandapplyanantisepticcreamandcover

itwithabandage.Incaseofasnakebite,tieatightbandageaboveandbelowthewoundtostopthespreadofvenominthebody.

2. Afirstaidkitmusthavebandages,apairofscissors,anantisepticlotion,thermometer,cotton, etc.

44


Aft er the completion of this chapter, the students will be able to: • explaintheparticle/moleculararrangementinsolids,liquidsandgases • listthepropertiesofstatesofmatter • explaintheeffectsofheatingandcoolingonmatter

Materials Required

Modelstoshowthemoleculararrangementsinsolids,liquidsandgases;injectionsyringes;balloons, etc.

Warm Up

Takeapieceofchalkandbreakitintopieces.Keeponbreakingitfurtherandfurthertillitcan’tbebrokenanyfurther.Tellthestudentsthatlikethechalk,everythingintheworldismadeoftinypiecesjoinedtogether.Th esepiecesformmatter.Introducethemtothethreestatesofmattergivingvariousexamples.AskthemtocompletethetaskgivenintheDelphi’sCornersection.

Concept Explanation

• States of matter:Usemodelsofsolids,liquidsandgasesandcomparethethreestatesofmatter.Encouragestudentstogivemoreexamplesofmaterialsofdifferentstatesofmatter.

• Change of state: TakethestudentsonashorttourtotheChemistrylabofyourschool.Demonstratetheprocessofevaporationandmeltingtothestudents.Explaintheprocessofcondensationandfreezing.Giveampleexamplesofinstancesofchangeofstateinourdailylife.Alsotalkaboutexpansionandcontractionwithexamples.

Reinforce


Explore


CHAPTER 7States of Matter

45

1. Complete the table to compare the properties of solids, liquids and gases.

Features Solid Liquid Gas

Packingofparticles

Shape

Volume

2. Identify the processes taking place in the following

(a) (b)

________________ ________________

(c) (d)

________________ ________________

WORKSHEET 1

46

1. Give two examples of each of the following.

(a)Solid

(b)Liquid

(c)Gas

2. Match the columns.

(a)Particlesmovefreely (i)Solid

(b)Particlestightlypacked (ii)Contraction

(c)Changeinsizeonheating (iii)Gas

(d)Changeinsizeoncooling (iv)Expansion

3. What is expansion? Explain it with the help of an example.

________________________________________________________

________________________________________________________

________________________________________________________

________________________________________________________

4. What is contraction?

________________________________________________________

________________________________________________________

WORKSHEET 2

47


A. 1. (a) (ii) (b) (i) (c) (iv) (d) (ii) (e) (iii) 2. (a) Condensation (b) Expansion (c) Freezing (d) Solid (e) SolidB. 1. When a substance is heated, its particles startmoving rapidly and occupymore

space.Th iscausesexpansion.Whenasubstanceiscooled,itsparticlesstartmovingslowlyandoccupylessspace.Th iscausescontraction.

2. Solid-chalk,salt;liquid-water,milk;gas-air,watervapour 3. A pooriswellsuponfrying.Th isisbecausetheairpresentinthedoughexpandson

heating. 4. Th eprocessofconversionofaliquidintogasonheatingiscalledevaporation. 5. Contractionoccurswhenasubstanceiscooleddown.Th eparticlesslowdownon

coolingandtakelessspace.Forexample,telephonecablesandelectricwiresappearstretched between the poles in winters.

6. Matterchanges its statewhen it isheatedorcooled.Forexample,whenwater iscooled,itformsice.Whenwaterisheated,itformswatervapours.

C. 1.

Features Solid Liquid Gas

Packing of parti-cles

Closelypacked Looselypacked Movefreely

Shape fixed Notfixed Notfixed

Volume fixed fixed Notfixed

2. Expansionandcontractionarethechangeswhichinvolveachangeinthesizeofasubstanceonheatingorcooling.

When a substance is heated, it expands. It means that the dimensions (length,thicknessorvolume)ofthesubstanceincreasewhenitisheated.

When a substance is cooled, it contracts. It means that the dimensions of thesubstancereduceoncooling.

3. Th eprocessofconversionofaliquidintoagasonheatingiscalledevaporation.Ontheotherhand,theprocessofconversionofagasintoaliquidoncoolingiscalledcondensation.

48

4. Water exists in all the three forms—solid (ice), liquid (water) and gas (vapour).Wheniceisheated,itmeltstoformwater.Onheatingwater,wegetvapours.Th evapourscondenseoncoolingtoformwaterandwaterfreezesonfurthercoolingtoform ice.

D. 1. Cracksoccurwhenthematerialusedtomakeroadexpandsinsummers.Itswellsandgetscracked.

E. 1. Water cycle involves evaporation ofwater from rivers and seas.Th iswater riseshigherupwhereit iscold.Watervapourscondensetoformwaterdropletsagainwhichcombinetogethertoformrain.

2. Th eairparticlesarefreetomovethroughouttheroom.Th eycarrythefragrancetoall parts of the room.

3. Deodorant spraysexpand in sunlight.Th eyneedmore spaceand thebottlemayburst.


Worksheet 1 1. Solid:Packingofparticles-Tight;Shape-Fixed;Volume-Fixed Liquid:Packingofparticles-Lesstight;Shape-Notfixed;Volume-Fixed Gas:Packingofparticles-Loose;Shape-Notfixed;Volume-Notfixed 2. (a)Melting (b) Evaporation (c)Freezing (d) CondensationWorksheet 2 1. (a)Ice,rock (b) Juice,water (c) Oxygen,nitrogen 2. (a)(iii),(b)(i),(c)(iv),(d)(ii) 3. Whenasubstanceisheated,itsparticlesstartmovingrapidlyandthusthesubstance

expands. A poori swells up on frying because the water present in the dough getsconvertedintosteamwhichexpandsonheating.

4. Whenasubstanceiscooleddown,themovementoftheparticlesslowsdownandthustheseparticlesoccupylessspace.

49


Aft er the completion of this chapter, the students will be able to: • classifyrocksintodifferenttypes • identifyusesofdifferenttypesofrocks • classifymineralsintodifferenttypes • identifyusesofdifferenttypesofminerals

Materials Required

Samplesofdifferenttypesofrocks

Warm Up

Beginyourtopicwiththetypeofflooringintheclass,schoolauditoriumandthehomesofthechildren.Askthemaboutthetypesofmaterialsusedtomakeashow-piece,floor,statues,etc.Tellthemaboutthedifferenttypesofrocksusedinmakingofdifferenttypesofmonuments.Th ereafter, ask the students to complete the task given in theDelphi’sCornersectionofthechapter.

Concept Explanation

• Rocks and their types:Beginthediscussionwiththestructureof the interiorof theearth.Discussaboutthecrust,mantleandcore.Th enproceedtothestudyofcrustoftheearthandrocks.Classifytherocksonthebasisoftheircompositionandproperties.Explaintheoccurrenceofigneousrocks,sedimentaryrocksandmetamorphicrocks.Makeatableontheboarddepictingclassificationandusesofdifferenttypesofrocks.Samples of rock pieces of different types can be brought to the class to explain thepropertiesofrocks.

• Minerals and their types: Continue your discussion to the composition of rocks.Explainhowmineralsareformedbyvariouschangesinnature.Classifythemineralsasmetallicandnon-metallicminerals.Reinforcetheconceptbyaskingexamplesofeachtypeofminerals.

• Uses of rocks and minerals:Askquestions to the students about the uses of diff erent typesofrocksandmineralsandlistthemontheboard.

Reinforce


CHAPTER 8Rocks and Minerals

50


Explore


51

1. Match the columns.

(a)Sandstone (i)Formedbythemetamorphismofgranite

(b)Limestone (ii)Rockwhichismadeofroundedstones

(c)Granite (iii)Porousrock

(d)Marble (iv)Formedbythemetamorphismofshale

(e)Pumice (v)Formedbytheslowcoolingoflava

(f)Shale (vi)UsedinmakingtheRedFortinDelhi

(g)Conglomerate (vii)Formedofsolidifiedclay

(h)Obsidian (viii)Metamorphosedrockrichinquartz

(i) Slate (ix)Softrockwithcalciumandanimalshells

(j) Gneiss (x)Formedbythemetamorphismoflimestone

2. What are the types of igneous rock?

____________________________________________________________

____________________________________________________________

3. Write any four uses of rocks.

____________________________________________________________

____________________________________________________________

____________________________________________________________

____________________________________________________________

WORKSHEET 1

52

1. Fill in the blanks.

(a)___________ is themolten hotmaterial which reaches the earth’ssurfacethroughavolcano.

(b)Th e_____________ismadeofwhitemarble. (c)____________isarockusedtomaketiles. (d)_____________rockcontainsmineralcalcite. (e)Th e___________isalsoknownasblackgold.

2. Write one use of each of the following.

(a)Slate ____________________________________________ (b)Sandstone ____________________________________________ (c)Limestone____________________________________________ (d)Gneiss ____________________________________________

3. Label the given picture.

(a)

(b)(c)

(d)

(e)

WORKSHEET 2

53


A. 1. (a) Ore (b) Coal (c) Coal (d) Sulphates (e) Gold 2. Sandstone—UsedinRedFortofDelhi Shale—Formedofsolidifiedclay Granite—Formedbyslowcoolingoflava Pumice—Porousrock Marble—FormedbymetamorphismoflimestoneB. 1. Whenthesurroundingrocksexertpressureonthemagma,itispusheduptothe

surfaceoftheearthduringavolcaniceruption.Th emoltenrockwhichflowsouttothesurfaceiscalledlava.Lavacoolsdowngraduallyandsolidifies.Itgetshardenedandformstheigneousrocks.Example:granite,obsidian,etc.

2. Th erocksonmountainsareweatheredbyrain,windandrivers.Th esmallbitsofrocks,pebbles, sand,mudandclaygetdeposited at river andoceanbeds.Th esesedimentspileovereachotherintheformoflayers.Upperlayersexertpressureonlowerrocksandhardenthem.Th eseformlayersofhardrockwhichareknownassedimentaryrocks.Example:sandstone,shale,etc.

3. Th erockswhichhavechangedtheirformarecalledmetamorphicrocks.Th eprocessofchangeinformiscalledmetamorphism,hencethename‘metamorphic’.Th eserockshadbeenigneousorsedimentaryinthepast.Example:slate,gneiss,etc.

4. Th e minerals which are used to obtain certain metals are called metallic minerals orores.Forexample,haematiteisusedtoextractiron.Gypsum,feldspar,micaandcalciteareexamplesofnon-metallicminerals.Th esearenotusedtoobtainmetals.

C. 1. Granite Obsidian Pumice • Granite is the most

common igneous rockformed by the slow coolingoflava.

• It mainly consists ofminerals such as quartz,feldspar and mica.

• It is of different coloursdependingonthequantityof feldspar in it.

• It is used as building,statueandfloormaterial.

• It isformedbyquickcoolingoflava.

• It is a smooth andglassyrock.

• It is used in makingcutting tools and inmaking ornamentsandjewellery.

• It is the only rockwhich canfloat as it hasnumerousairpocketsorpores.

• Ithaslightgreyorpeachcolour.

• Itisusedinmakinglight-weightbuildingmaterial,skin scrubber etc. It isalso used by dentistswho polish teeth usingpowdered pumice.

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2. Sandstone Conglomerate Shale Limestone

• Itisasoftrockmadeofsand particles cemented together.

• Itisfoundinred,pink,brownandyellowcolours.

• Itisusedinmakingbuildings.Themost famous exampleistheRedFortinDelhi.

• Itismadeofround pebbles, gravelandsand cemented together.

• Itisgreyororangeincolour.

• Itisusedinmakingornaments when polished.

• Itismadeofsolidifiedclayandmudwhich form layers.

• Itisusedtomaketiles,bricksandcement due to itshighclaycontent.

• Itismadeofcalcite which is also a part of animal shells.

• Itisfoundingreyandwhitecolour.

• Itisusedinmakinglime, cement, chewinggum,chalk,glass,linoleum etc.

3. Marble Slate Gneiss Quartzite

• Itisformedfromlimestone.Itiswidelyusedinmakingfloors,statues and ornamentalobjects.Itshinesonbeingpolished.TheTajMahalinAgraisthe most beautiful construction made bywhitemarble.

• Slateismadefrom shale. Itcanbebrokenintothinlayersand is used inmakingbricks,cement, black-boardand slates.

• Gneissisformed from granite.Ithas striped appearance and is used asabuildingstone.

• Itismadefromsandstone and containsquartzmineralinhighpercentage.Itisanextremelyhardrock.Tisusedinmakingstatues.Itfindswide application in ceramic industry.

D. 1. Sedimentaryrock 2. Itisformedfromdeadremainsofswampyforestsandvegetation. 3. Itisusedasacookingfuelandasaheatingfuelinthermalpowerplants.E. 1. Thepreciousstonesarefoundintheformofcrystals.Theyhavebeautifulcolours,

shineandareextractedfromtheearth.thusthesearecostlyandusedinmakingjewellery.

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2. Sandissofttotouch.Whensandparticlesarecementedtogether,theyformveryhardrockcalledsandstone.

3. Limestoneisnotasstrongassandstoneandgranite.Italsoreactswithwater.


Worksheet 1 1. (a)(vi),(b)(ix),(c)(v),(d)(x),(e)(iii),(f)(vii),(g)(ii),(h)(viii),(i)(iv),(j)(i) 2. Granite,obsidianandpumicearethetypesofigneousrocks. 3. Rocksareusedasbuildingmaterials,asgemstones,asafuelandasasourceofvarious

metals.Worksheet 2 1. (a) Magma (b) TajMahal (c) Marble (d) Limestone (e) Petroleum 2. (a)Itisusedtomakeblackboardandcement. (b)Itisusedinconstructionofbuildings. (c)Itisusedinmakinglime,cement,chewinggum,chalkandglass. (d)Itisusedasabuildingstone. 3. (a)Ashandgascloud (b) Lava (c) Cratercone (d)Vent (e) Magmachamber

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Aft er the completion of this chapter, the students will be able to: • tracethehistoryofmeasurementoflength,massandtime • makemodelsofstandardmeasuringdevices • comparethenon-standardandstandardmeansofmeasurement

Materials Required

Ruler,measuringtape,thermometer,stopwatchmeasuringcan,standardweights,etc.

Warm Up

Beginwithsimpleexamplesfromdailylifesuchaswhatwouldhappenifyourtailorsewedclotheswithout takingmeasures;whydoes a vegetable vendormeasure the vegetablesbeforeselling,etc.Discussthevariousinstanceswheremeasuringisimportant.Th ereafter,askthestudentstocompletethetaskgiveninDelphi’sCornersection.

Concept Explanation

• History of measurement: Makethesessioninteractivebyexplainingtheconceptintheformofastory.Allowstudentstocomparethelengthsoftheirtablesusinghandspanandcubit.Explainwhytheyarecallednon-standardunits.

•SI units of measurement:Explaintheusesofstandardunits.Explainthemeaningoflength,mass,capacity,timeandtemperature.

• Measurements of some physical quantities:Showthemeasuringdevicesfor length,mass, time, capacity and temperature. Demonstrate their working. Give hands-on experience to the students by using these devices. Talk about the accuracy ofmeasurements.

Reinforce


Explore


CHAPTER 9Measurement

57


(a)Th elengthofthefootfromitsheeltoitsbiggesttoe. _________

(b)Anobjectwhichoscillatestomeasuretime. _________

(c)Anyquantitythatcanbemeasurednumerically. _________

(d)Aninstrumentusedtomeasurelengthofalinesegment._________

(e)Adeviceusedtomeasuretemperature. _________

2. Write the SI unit of each of the following.

(a)Time

(b)Temperature

(c)Capacity

(d)Mass

(e)Length

3. Convert the following.

(a)5days = ________ seconds

(b)2600mL = ________ L

(c)56kg = ________ g

(d)5000mm = ________ m

(e)765cm = ________ m

WORKSHEET 1

58

1. Identify each of the following devices and state its use.

(a) _________________________________

_________________________________

(b) _________________________________

_________________________________

(c) _________________________________

_________________________________

(d) _________________________________

_________________________________

WORKSHEET 2

59


A. 1. (a) 1000 (b) 86400 (c) 100 (d) 3600 (e) 1000 2. (a) Th ermometer (b) Measuringcan (c) Odometer (d) Balance (e) MeterscaleB. 1. Th ermometerisusedtomeasuretemperature. 2. (a) Centimetre (b) Metre (c) Kilometre 3. We use submultiples of kilogram to measure smaller masses. For example, the

massofafootballismeasuredin‘gram(g)’whilethemassofdoseofamedicineismeasuredinmilligram(mg).

4. Non-standardisedunitsformeasuringtimearesandclockandsun-dial. 5. Evenbeforethedevelopmentofmodernmeasuringtechniques,measurementshave

been made since ancient times. Time was measured earlier with the help of position ofsunormoon.Lengthwasmeasuredintermsoflengthofbodypartssuchashand,arm or foot.

C. 1. Weusemeasurementofmasstoweighfruitsandvegetables,medicines,grains,etc. Tomeasuremass,theSIunitiskilogram(kg).Kilogramisusedtomeasuremasses

suchasabagofwheat,massofababy,etc. We use submultiples of kilogram to measure smaller masses. For example, the

massofafootballismeasuredin‘gram(g)’whilethemassofdoseofamedicineismeasuredinmilligram(mg).

2. Measurementplaysanimportantroleinourlife.Rightfromthemorningtobedinnight,wemeasureseveralthings.Wemeasuremilkgivenbymilkman.Wemeasuretimetogetup,timetoreachschool,timetoplay,etc.Wemeasuredistancebetweenthewicketsonacricketpitch.Wemeasuremassofvegetablesandfruitsboughtbyus and so on.

Measuring different quantities is an important part of our life. We measure anumberofthingsinoureverydaylife.Anythingwhichcanbemeasuredisknownasaphysicalquantity.Wemeasurevariousphysicalquantitiessuchaslength,mass,capacity,temperature,time,etc.inourdailylife.

3. Th eunitswhichareinternationallyacceptedandhavethesamemeasureeverywhereintheworldarecalledSIunitsofmeasurement.Th eSIunitsofdifferentphysicalquantitiesaregivenbelow.

Length metre(m) Mass kilogram(kg)

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Capacity litre(L) Time second(s) Temperature Kelvin(K) 4. Th e non-standardised units of measurement are not the standard means of

measuring.Th usweneedtoswitchtomoreaccuratemeansofmeasurement.Th isinvolvestheuseofstandardunitsformeasurement.SIunitsaremoreaccurateandacceptedworldover.Th eydonotvaryfrompersontoperson.

D. 1. Th ermometer 2. Tomeasuretemperatureofabody 3. Kelvin(K) 4. DegreeCentigrade(°C)anddegreeFahrenheit(°F)E. 1. Measuringtapeismoreaccuratethanhandspan.Th ehandspanwillchangewiththe

ageofthechild. 2. Th e mass of one litre volume of oil is 910 g. So, the given information is not

misleading.


Worksheet 1 1. (a)Foot (b) Pendulum (c) Physicalquantity (d)Ruler (e) Th ermometer 2. (a) Second (b) Kelvin (c) Litre (d)Kilogram (e) Metre 3. (a) 1day=86400s;So,5days=5×86400=432000s (b) 1000mL=1L;So,2600mL=2.6L (c) 1kg=1000g;So,56kg=56×1000=56000g (d) 1000mm=1m;So,5000mm=5m (e) 100cm=1m;So,765cm=7.65mWorksheet 21. (a) Clock;Itisusedtomeasuretime. (b)Th ermometer;Itisusedtomeasurebodytemperature. (c)Tank;Itisusedtomeasurethecapacity. (d)Measuringtape;Itisusedtomeasurelength.

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Answers to Summative Assessment 1

A. 1. Germination 2. Potato 3. Vitamins 4. Siberiancranes 5. Sternum 6. Communicable 7. Fireextinguisher 8. Freezing 9. Melting 10. OdometerB. 1. F 2.F 3. T 4. T 5.TC. Poliovaccine-helpstopreventpolio Cartilage-outerear Pivotjoint-foundbetweenskullandbackbone Bonemarrow-helpsinredbloodcellformation Pumice-porousrockD. 1. Inhumanbreathingorgansarelungswhilefishbreathethroughgills. 2. Habitat is thenaturaldwellingplaceof anorganism.Forest anddesert are two

examplesofhabitat. 3. Th eactionsthatarecarriedoutbyourbodyasasuddenandautomaticresponse

toaneventarecalledreflexactions.Forexample,ifyouaccidentallyputyourhandoveracandle,yousuddenlymoveyourhandaway.

4. Togiveimmediatehelpandtreatmenttoavictim,firstaidkitisimportant. 5.Whena substance isheated, itsparticles startmoving rapidly and the substance

expandswhilewhenasubstanceiscooleddown,themovementofparticlesslowsdownandtheseparticlesoccupylessspaceandthisiscalledcontraction.

E. 1. Intheearlystagesofgermination,theseedlinggetsitsfoodfromthecotyledons.Th eseedlingsoonstartstogrowrootsinthedownwarddirection.Itabsorbswaterandnutrientsfromthesoilwiththehelpoftheseroots.Next,theshootdevelops,whichgrowsintheupwarddirection.Th eshootthendevelopsleaves.Th eleavesstartpreparingfoodfortheplantbytheprocessofphotosynthesis.Agrowingseedgetsairthroughtheporesinthesoil.

ReferFigure1.1onpage9 2. Mona’smothershouldtellherthatabalanceddietmakesushealthyandfitand

keepsusawayfromdiseases.Monashouldunderstandtheimportanceofbalanceddiet.

3. Inball-and-socket joint, onebone ends in a ball andfits into theother socket-shapedbone.For example, shoulder joint.Pivot jointhelps inmovementof theheadupwards,downwardsandsideways.Th isjointisfoundbetweenskullandthefirsttwovertebraeinthebackbone.

4. Massofheavierobjectsismeasuredinkilogram(kg)whilethemassoflightobjectsismeasuredingram(g).

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5. Granite:Itisformedbyslowcoolingoflava.Itmainlyconsistsofmineralssuchasquartz,feldsparandmica.Itisusedforbuildingconstruction.

Obsidian:Itisformedbyquickcoolingoflava.Itisusedformakingcuttingtoolsand ornaments.

Pumice:Itistheonlyrockthatcanfloatonwaterasithasnumerousairpores.Itisusedasaskinscrubberanditspowderedformisusedforpolishingteeth.

F. 1. Dispersal by wind:Seedsofsomeplantsarelightweightandarehairyandwinged.Theseseedscanbeeasilycarriedawaybywind.Examplesaredandelion,cottonand madar.

Dispersal by water: Someplantshave spongy seedsor seedswithfibrousoutercovering,whichhelps these seeds stayafloat inwater.Watercarries these seedsto largedistances.Examplesof suchplantsare lotus (spongyseed)andcoconut(fibrousoutercoveringontheseed).

Dispersal by animals:Animalsusuallyeatfruitsandthrowawaytheseeds.Somefruitsareeatenupbybirdsandanimalsalongwiththeseeds.Theseseedsarethenexcretedinthedroppingsorfaecesoftheseanimalsandbirds.Someseedshavehooks,spinesorhair,whichclingtothebodyofanimalsandtheseseedsthengetcarriedawayfromtheirparentplant.Examplesarexanthium(hooks)andspeargrass(spines).

Dispersal by fruit explosion: Poppy, pea, violet and bean fruits burst open onripening.Theseedsgetscatteredinalldirections.

2. Skull:Itconsistsof22bones.Outofwhich8bonescoverthebrainwhile14bonesformtheface.Itprotectsthebrain.

Ribcage: The bones present around the chest are called ribs. There are 12 pairs of ribsinourribcage.Ribcageprotectstheheartandthelungs.

Backbone:Itconsistsofaseriesof33smallbones.Itprotectsthespinalcord. Limbs:Therearetwopairsof limbs intheskeleton: theforelimbsandthehind

limbs.Limbshelptodoactivitieslikegraspingobjectsandmovement. 3. Thebonesintheskeletonarejoinedtoeachotheratplacescalledjoints. Ball-and-socket joint: Thetypeofjointinwhichoneboneendsinaballandfits

intotheothersocket-shapedboneisaball-and-socketjoint.Shoulderjointandhipjointareexamplesoftheball-and-socketjoint.

Hinge joint:Asthenamesuggests,thistypeofjointworkslikeahingeinadoor.Forexample,theelbow,knee,fingersandtoes,allhavehingejoints.

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Pivot joint:Thepivotjointisfoundbetweentheskullandthefirsttwovertebraeinthebackbone.Thisjointhelpsinthemovementoftheheadupwards,downwardsandsideways.

Gliding joint:Thetypeofjointwhichallowsthebonestoglideovereachotheriscalledtheglidingjoint.Itisfoundinthewristandankle.

4. (a)Cause:Deficiencyofiron Symptoms:Weakness,lethargy,darkcirclesaroundeyesandlossofappetite (b)Cause:Deficiencyofiodine Symptoms:Swollenglandintheneckandimpropergrowth (c)Cause:DeficiencyofvitaminD Symptoms:Softeningandbendingofbones 5. Communicablediseasesarethosediseasesthataretransmittedfromasickperson

toahealthyperson.Thehousesshouldbekeptclean,well-ventilatedandfreeofmosquitoes.Thereshouldbesufficientsunlightenteringthehouse.Communicablediseasescanbepreventedbyfollowingthesehabits.

• Watershouldbeboiledandkeptcovered.Foodshouldalsobekeptcovered.Oneshould not eat stale food.

• Invillages,waterinthewellsshouldbechlorinatedregularly. • Watershouldnotbeallowedtostagnateasmosquitoeslayeggsinthestanding

water. • Oneshoulddrinkpasteurisedmilk. • Weshouldnotuseutensils, towels,handkerchiefsandother thingsusedbya

personsufferingfromcommunicabledisease. • Alwayswashhandswithsoapandwaterbeforeandaftereatingfood,andalso

after using the toilet. Use a handkerchief while coughing or sneezing. Thispreventsthespreadofdisease-causinggerms.

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Model Test Paper 1 50 marks

A. Fill in the blanks. (1 × 10 = 10) 1. __________isthemeasurementofthedegreeofhotnessorcoldness

ofabody. 2. The hot and molten rocks present in the earth’s core are called

____________. 3. A________isaconditioninwhichthetissuesareinjuredaroundthe

joints. 4. A pooriswellsuponfryingdueto____________. 5. ___________protectsthespinalcord. 6. Mixednervescarrymessagesfromthe__________tothe_________. 7. Whalesexchangeairthrough__________________. 8. Sheddingofskinbysnakesiscalled_________________. 9. Goitreoccursduetothedeficiencyof________________. 10. Inpoppyandpea,theseedsgetdispersedby____________.

B. Match the following. (1 × 5 = 5) (a) Mass (i) Cooling (b) Obsidian (ii) Reflexaction (c) Contraction (iii) Igneousrock (d)Spinalcord (iv) Penguins (e) Flippers (v) Kilogram

C. State whether the following statements are true or false. (1 × 5 = 5) 1. Cubitisthelengthofthefootfromitsheeltoitsbiggesttoe. 2. Slateisametamorphicrock. 3. Atourniquetcanbeusedinfractures. 4. Thereare8bonesintheskullthatcoverthebrain.

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5. Vaccineisasubstancewhichprotectsourbodyagainstdiseases.

D. Answer the following briefl y. (2 × 5 = 10) 1. Whyaregapsleftbetweentherailsoftherailwaytrack? 2. Whatcanonedoincaseofmajorburns? 3. Definereflexactionwiththehelpofanexample. 4. Writethefunctionoftheskullandtheribcage. 5. Writethefunctionsofroughage.

E. Answer the following in detail. (3 × 5 = 15) 1. Explaintheagentsofthecommunicablediseases. 2. Explainthedispersalofseedsbywindandwater. 3. Writethedifferencebetweenmarbleandquartzite. 4. Explainhingejointandglidingjoint. 5. Whatarethefeaturesofdesertandmountainhabitats?

F. Look at the given picture carefully and answer the following question. (2 + 3 = 5)

1. Howcanthisanimalmove? 2. Whatarethebreathingorgansinthisanimal?

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Aft er the completion of this chapter, the students will be able to: • prepareamodelofsoilprofileandidentifylayersofsoil

• listthecausesofsoilerosion

• discussmethodsofsoilconservation

Materials Required

Gardensoil,materialforactivity,videoclipsofsoilerosion

Warm Up

Talktostudentsaboutsoilanditsimportance.Soilisneededforgrowingcrops.Farmersgrowcropsinsoil.Tellthemthatsoilcontainsair,waterandminerals.Reinforcethetopicbydiscussingtheimportanceofsoil.

Concept Explanation

• Layers of soil:PerformActivity1withthestudentsinclass.Demonstratehowsoilisorganisedintodifferentlayers.Discussthepropertiesofdifferentlayersofsoil.Comparethelayersintermsofparticlesizeandcomposition.

• Formation of soil: Show the video clip onweathering of rocks. Explainhow soil isformedby theactionofwind,waterandheat.Ask students tomakeaflowchart todescribetheprocessofweathering.

• Soil erosion and its causes: Hold a discussion on how the topmost layer of soil isremovedbywaterandwind.Discussitshazardsindetail.Explainhowitaffectsthecropyieldandpollutestherivers.Incorporatetheeffectofdeforestationontheincreasedrateof soil erosion.

• Soil conservation and its methods: PerformActivity2inclass.Explainthestudentsthatsoilcanbeconservediftreesandgrassesareplantedonemptypatchesofland.Alsodescribethemethodsfollowedbyfarmerssuchascovercrops,bunds,terracefarming,etc.

CHAPTER 10Soil

67

Reinforce


Explore


68


S. No. Layers of soil from top to bottom Features (any two)

(a)

(b)

(c)

(d)


(a)_______________

(b)_______________

(c)_______________

(d)_______________

WORKSHEET 1

69

1. Identify the given pictures and defi ne each.

(a) _________________________________

_________________________________

(b) _________________________________

_________________________________

(c) _________________________________

_________________________________


(a)____________ (b)____________ (c)____________ (d)____________

WORKSHEET 2

70

Answers to coursebook

A. 1. (a) F (b) F (c) F (d) T 2. (a) Soilconservation (b) Embankments (c) Wind (d) TerracefarmingB. 1. Th eprocessofbreakingofrocksintofineparticlesbydifferentprocessesinnature

iscalledweathering. 2. Th ewind,rainandriversaretheagentsofweathering. 3. Duringrains,farmersbuildmarginalbundsalongtheboundaryoftheirfieldsto

preventthesoilfromflowingawaywithrainwater.Treesandbushesarealsogrownalongtheboundaryoffields.

Hillslopesarecut to formterraceorsteps.Th ispreventsflowof fertilesoilwithwaterdownhillandpreventssoilerosionfrommountaintops.

4. Th e soilbrought toplainsby riversgetsdeposited.Th ese regionsare coveredbynaturalvegetationandtreeswhichpreventsoiltodrainawayfurther.Deforestationremovesthiscoverfromtheland.Asaresult,thetoplayerofthesoilgetsremovedbyblowingwindandflowingwater.

5. Alongtheriverbanks,embankmentsshouldbebuilt.Th ishelpstopreventtheentryofriverwaterintotheagriculturallandsclosetothebanks.

6. Onceitisremoved,thesoilneedsalongtimetoreplenishitselfasweatheringisaveryslowprocess.Th us,weneedtoconservesoilagainsterosion.

7. Deforestation,removalofcovercrops,etc.areresponsibleforsoilerosion.C. 1. Th esoilprofileconsistsofthreemainhorizons-A,BandC. Horizon A (the top soil): Th etopsoilmainlyconsistsofveryfineparticlesofclay

and sand.Th eorganicmatter is formedbydead anddecayingplant andanimalmatterandisknownashumus.

Horizon B (the sub-soil): Th e sub-soil occurs beneath the top soil. It containsgravel,rocksandstonesoflargersizecomparedtoparticlesintopsoil.Ithassmallamountoforganicmatterinit.Itallowswatertoseepthroughit.

Horizon C (the bed rock): Th ebed rock consists of large rocksdeep inside theearth.Th eserocksdonotallowwatertoseepthroughthem.Th eseoccurquitedeepinside the earth.

2. Windandwaterarethemajoragentsofsoilerosion.Windscausesandstormsandblowawaythefertilelayerofsoil.Th isaffectsfarmingtremendously.Evenplantsdieduetolackofnutrientsandlackofcoverontheroots.

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3. Somemeasureswhichcanbetakentopreventsoilerosionareasfollows. • Fellingoftreesshouldbeprevented.Treesarethemajorfactorswhichconserve

soilfromerosion.Thusmoreandmoretreesshouldbegrowninemptylands. • Over-grazingbycattleshouldbecontrolled.Landwhichbecomesemptyshould

begrownwithcovercropsandgrassestopreventwindfromblowingawaythetop soil.

• Whenthecropsareharvested,farmersshouldcoverthelandwithcovercropstopreventsoilerosionbywind.

• Alongtheriverbanks,embankmentsshouldbebuilt.Thishelpstopreventtheentryofriverwaterintotheagriculturallandsclosetothebanks.

• Duringrains,farmersbuildmarginalbundsalongtheboundaryoftheirfieldstopreventthefertiletoplayerofsoilfromflowingawaywithrainwater.Treesandbushesarealsogrownalongtheboundaryoffields.

• Hillslopesarecuttoformterraceorsteps.Thispreventsflowoffertilesoilwithwaterdownhillandpreventssoilerosionfrommountaintops.

4. Initially, rainwaterdeposits into crackspresent in the rocks. In cold climate, thewaterfreezesintoice.Icepushestherocksatallsidesandcausestherocktocrackfurther.Thisprocessrepeatsitselfagainandagaintilltherockbreaksdownbythepressureexertedby ice.Rivers take thesebrokenpieces to largedistance. Induecourse, the pieces brush against each other till they becomefiner and finer andfinallyformsoil.Thesoilgetsdepositedwhentheriversflowintoplains.Particlesbecomefinerevenbytheactionofwind.

D. ReferFigure10.2onpage87.

E. 1. Useofplasticisanothermajorsourceofsoilpollution.Plasticwillnotbedecomposedinsoilasitisanon-biodegradablesubstance.Thus,plasticwastessuchasbottles,gadgetbodies,etc.areharmfulforthesoil.

2. RiverHwangHoflowsinChina.ItisalsocalledtheYellowriver.Itchangesitscoursefrequentlyandoftencausesfloods.ItthereforetermedastheSorrowofChina.

3. Whenthecropsareharvested,farmersshouldcoverthelandwithcovercropstopreventsoilerosionbywind.

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Worksheet 1 1. (a) HorizonO;Itisrichinhumusanditisverydarkincolour. (b)HorizonA;Itmainlyconsistsofclayandsand.Plantsgrowinthislayer. (c) HorizonB;Itcontainsgravel,rocksandstones.Itallowswatertoseepthroughit. (d)HorizonC; It consists on small piecesof rocks. It doesnot allowwater to seep

throughthem. 2. (a) HorizonO(Humus) (b) HorizonA(Topsoil) (c) HorizonB(Subsoil) (d) HorizonC(Regolith)Worksheet 2 1. (a) Soilerosionbywind (b) Deforestation (c) Soilerosionbywater 2. (a) Watercollectsintherockcrack. (b)Waterfreezesandexpands,forcingcrackstowiden. (c) Icethaws,contractsandwatergetsdeeperintocracks. (d)Repeatedexpansionandcontractioncausesfurthercrackstillrocksplits.

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Aft er the completion of this chapter, the students will be able to: • listtheeffectsofforcewithexamplesofeach • discusshowmachinesmaketheworkeasy • describetheworkingofmachinesofdifferenttypes • explainhowdifferentformsofenergyareinter-convertible

Materials Required

Somesimplemachines,materialsforactivities

Warm Up

Beginyour topicwitha story.Tell the studentsabouthowNewtongot toknowabouttheforceofgravityinnature.Moveontootherexamplesofforcearoundus.Discusstheimportanceofforceinpracticalsituations.AskstudentstocompletethetaskgivenintheDelphi’sCornersection.

Concept Explanation

• Types of forces:Usepostersofpeopleexertingforcesofdifferenttypesandaskwhateffectsdoestheappliedforceiscausingontheobjectsineachcase.Graduallymovetothedefinitionofforce.Giveexamplesofforceindailylife.Discusstheeffectsofforces.Moveontotypesofforces.Performsimpleactivitiestodemonstratedifferenttypesofforce.

• Work:Explainwhenworkissaidtobedoneintermsofscience.Performsimpleactsofapplyingforceandaskinwhichsituationworkisdone.

• Energy:Discussthetypesofenergyinoursurroundings.Askstudentstogiveexamplesoflightenergy,soundenergy,mechanicalenergy,windenergy,solarenergyandheatenergy.Explainthatdifferentformsofenergycanbeinterconverted.Giveexamplestoreinforce this concept.

• Simple machines:Usesimplemachinessuchasscissors,tongs,pliers,nutcrackers,etc.toexplainthedifferenttypesoflevers.Providehandsonexperiencetothestudentsofdifferentsimplemachines.Holdagroupdiscussiononhowmachineshavemadeourlifesimplerandworkeasier.

CHAPTER 11Force and Energy

74

Reinforce


Explore


75

1. Identify the eff ect of force being caused in each of the actions shown below.

(a) _________________________________

_________________________________

(b) _________________________________

_________________________________

2. Name the types of machines shown in the following pictures.

(a) (b)

________________ ________________

WORKSHEET 1

76

1. Give one example each of the bodies possessing the following types of energy.

(a)Solarenergy _________________________________

(b)Soundenergy _________________________________

(c)Mechanicalenergy _________________________________

(d)Windenergy _________________________________

(e)Heatenergy _________________________________

2. Identify the type of force.

(a) (b)

_____________________ _____________________

(c)

_______________________

WORKSHEET 2

77


A. 1. (a) speed,shape (b) machines (c) energy (d) heat,light (e) fixed,movable 2. (a) Mechanicalenergy (b) Lightenergy (c) Windenergy (d) Electricalenergy (e) Mechanicalenergy (f) SolarenergyB. 1. Energyisdefinedastheabilityofanobjecttodowork.Differenttypesofenergyare

soundenergy,mechanicalenergy,windenergy,heatenergy,electricalenergyandlightenergy.

2. Forceisthepushandpullappliedbyanobjectonanother.Differenttypesofforcesaregravitationalforce,muscularforce,frictionalforceandelectrostaticforce.

3. Machinesarethedeviceswhichmakeourworkeasier,fasterandsimpler.Th isispossiblewhenweareabletoapplyforceatspecificpointwhichincreasestheimpactof force. Example: pushing a load down an inclined plane, cutting a paperwithscissors.

4. (a) (b)

C. 1.

ClassILever

ClassIILever

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ClassIIILever

Example: ClassILever–Scissors ClassIILever–Nutcracker ClassIIILever–Stapler 2. Lever: Aleverisasimplemachineinwhichtheeffortisexertedaboutapointcalled

fulcrumandtheeffectisobservedatloadatanotherpoint.Hammer,scissors,tongs,nutcracker,etc.areallexamplesoflevers.

Wheel and axle: Awheelisattachedtoarigidrodatitscentre.Asthewheelrotates,theaxlealsorotates.Acarsteering,adoorknob,ascrew-driver,etc.areallexamplesofwheelandaxle.

Pulley: Pulleyisawheelwhichhasagrooveinitsrim.Aroperunsthroughthegroove.Atoneendoftherope,theloadisattachedwhiletheotherendiswheretheeffortisappliedbypullingtherope.Examplesofpulleyareseenoverthewellsandatflagpoles.

Inclined plane: Aslopingsurfaceonwhichheavyobjectscanberolledorslideiscalledaninclinedplane.Barrelsareloadedintocarriervehiclesthroughinclinedplanes.

Screw: Whenaninclinedplaneiscoiledintoaspiral,itformsascrew.Examplesofscrewsarescrewcapofbottle,screwjack,etc.

Wedge: Whentwoinclinedplanesmeetatapointedend,awedgeisformed.Th eseareoftenusedindeviceswhichsplitopenanobject.Forexample,theheadofanaxe,cuttingedgeofknife,etc.arewedges.

3. Th eeffectsofforcearegivenbelow. • Forcecanmakeastationaryobjectmove.Forexample,ifaplayerkicksafootball

placedatrest,itstartstomoveinthedirectionoftheforceappliedbykicking. • Forcecanslowdownorstopamovingobject.Forexample,ifacartismoving

in the forward direction and force is applied in the direction opposite to the direction of its motion, then the cart would slow down or stop.

• Forcecanchangetheshapeofanobject.

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4. Th etypesofenergyareasfollows. Light energy: Lightistheformofenergywhichhelpsustosee.Th esourcesoflight

inoursurroundingsarebulb,candle,fire-flies,tubelights,etc. Sound energy: Soundenergyenablesus tohear.Wespeak,playguitarorsinga

songtoproducesoundenergy. Mechanical energy: Th eenergypossessedbyanobjectduetoitsmotionorheight

abovethegroundiscalledmechanicalenergy.Amovingcar,ahangingchandelier,arollingfootball,etc.possessmechanicalenergy.

Electrical energy: Electrical energy is obtained in the form of electric currentpassing through thewires.Th emodern gadgets such asmusic systems, laptops,mobile phones, etc. cannot function without it.

Wind energy: Th eenergyofthemovingaircanbeusedtorotateawindmill.Energyofthewindisusedtosailboatsandwinnowthegrainsinfields.

Solar energy: Sunistheultimatesourceofallenergy.Solarenergyismainlyavailabletousintheformofheatandlight.

Heat energy: Heatenergyisneededtogetwarmth,cookfoodandtorunavehicle.D. 1. Pliers 2.

E

FL

3. ClassIleverasfulcrumliesbetweenloadandeffort.E. 1. Th ewalldoesnotmove.Sonoworkisdone. 2. Usingapulleyiseasieraslessforcehastobeapplied. 3. Itiseasiertoslidetheloadsdowntheinclinedslopesratherthancarryingthem.

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Worksheet 1 1. (a)Forcecanmoveastationaryobject. (b) Forcecanchangetheshapeofanobject. 2. (a)Screw (b) InclinedplaneWorksheet 2 1. (a)Sun (b) Audioplayers (c) Amovingcar (d) Movingair (e) LPG 2. (a) Gravitationalforce (b) Magneticforce (c) Electrostaticforce

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Aft er the completion of this chapter, the students will be able to: • studythepropertiesofair • performsimplestepsofpurifyingwater • appreciatetheimportanceofairandwaterasessentialsoflife

Materials Required

Stufflistedinactivitiestobeperformedinclass

Warm Up

Beginthelessontakingaboutthegiftsnaturehasprovideduswith.Talkabouthowweallarecollectivelyresponsibleforkeepingourearthsafeandourresourceseverlasting.Discusshowairandwaterareourimportantresources.NowaskthechildrentocompletethetaskgivenintheDelphi’sCornersection.

Concept Explanation

• Air and its composition:Useanavailablepiecharttoexplainthecompositionofair.Explainthatnitrogenisthemostabundantgas.Discusstheimportanceofoxygeninourlife.Alsobrieflydescribehumidityanditseffects.

• Atmosphere: Use a chart of layers of atmosphere. Explain the use of each layer.Encouragethestudentstorepresenttheusesofeachlayerofatmosphereonthechartpictorially.Performactivities1,2and3inclasstodescribethepropertiesofair.Discusstheobservationsandmotivatethestudentstoarriveattheconclusionthemselves.

• Water: Explain the importanceofwater on earth. State the sources ofwater and itsuses.Performtheexperimenttodistinguishbetweensolubleandinsolubleimpuritiesinwater.Explainthatitisnecessarytoremovetheimpuritiesfromwaterbeforeusingit.

• Removal of impurities from water: Performactivitiesbasedonfiltration,sedimentationand decantation and loading in class. Ask questions to students based on theirobservations.Encouragethemtoperformtheexperimentsontheirown.Discusstheprocess of distillation in class.

CHAPTER 12Air and Water

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•Purification of drinking water:Useamodelforthestudyofpurificationofdrinkingwater.Explaineachstepindetailalongwithitssignificance.Talkaboutothermethodsusedforpurifyingwaterathome.

Reinforce


Explore


83

1. Give one word answer for the following. (a)Achemicalusedtodisinfectwater. ___________ (b)Substanceusedtoincreasetherateofsedimentation byloading. ___________ (c)Anoldhouseholdmethodofcleaningwaterfor drinking. ___________ (d)Th elargestreservoirsofwaterontheearth. ___________ (e)Processofpurifyingwaterformedicaluse. ___________

2. Identify the following processes and defi ne each of them.

(a)

______________________________________________________

(b)

______________________________________________________

WORKSHEET 1

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WORKSHEET 2

1. Label each layer of the atmosphere in the given diagram. State the function of each layer.

(e)

(d)

(c)

(b)

(a)

(a)___________________________________________________

(b)___________________________________________________

(c)___________________________________________________

(d)___________________________________________________

(e)___________________________________________________

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A. 1. (a) F (b) T (c) T (d) F (e) T 2. (a) Chlorine (b) Alum (c) Humidity (d) FiltrationB. 1. (a) Troposphereisthelowestlayerinwhichchangesinweatheroccur. Th e layer above troposphere is called stratosphere.Th e air-planes fly in this

layer.Th islayercontainsplentyofozonegaswhichpreventstheharmfulraysofthesunfromreachingtheearth.

(b) Soluble impurities are the ones which dissolve in water and cannot be seenthroughnakedeye,forexample,salt.

Insolubleimpuritiesaretheoneswhichdonotgetdissolvedinwaterandcanbeseenthroughnakedeye,forexample,sand,mud,germs,etc.

2. Ithelpsinmaintainingtherighttemperatureontheearthforlivingbeingstosurvive.Itprotectsusfromtheharmfulrays(ultravioletrays)ofthesun.Italsoprotectsusfrom small rocks thathit the earth from the space.Th ese small rocks are calledmeteoroids.Mostofthesemeteoroidsburnupintheatmospherebeforereachingthe earth.

3. Th e bubbles are of air thatwas enclosed in the glass. It proves that air occupiesspace.

4. Boilingisthesimplestandthemosttrustedwayofpurifyingwateratourhomes.Waterisheatedandmadetoboilforabout8-10minutes.Th iskillsallthegermspresentinwater.Othermethodsarefiltration,distillationandchlorination.

5. Nitrogen is themost abundant gas in the atmosphere. It controls the process ofburninginair.Itdoesnotsupportburning,butifnitrogenwasnotthere,itwouldbedifficulttocontrolfireontheearth.Italsoformsimportantpartofproteinsandseveralothercompounds.Butwecannotobtainthisnitrogendirectlyfromair.Th eplantsgetnitrogenfromsoilwiththehelpofsomemicroorganisms.Meatandfisharealsosourcesofnitrogen.

C. 1. Filtration: Infiltration,themixtureispassedintoanothercontainerthroughafilterpaper.Th efilteringconeisplacedinthefunnelandthefunnelisresteduponthecontainerinwhichthecontentsaretransferred.Th emixtureofsandandwaterisstirredwellandpouredintothefunnel.Th esandparticlessettleoverthefilterpaperand clear water falls down into the container. Th e collected clear water is called the filtrate.

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Sedimentation and decantation:Insedimentation,thesandywaterisallowedtostandundisturbedfor15-20minutes.Thesandsettlesdownatthebottomofthecontainer.Thissettledimpurityiscalledsediment.Theclearwaterabovethesedimentispouredintoanothercontainercarefully.Thisprocessiscalleddecantation.Theliquidsocollectedondecantationiscalledsupernatantliquid.

2. Airhasweight. Taketwoballoonsandinflateoneofthem.Takeabalanceandputdeflatedballoon

ononepanand inflatedballoonon theotherpan.Thepanwhichholds inflatedballoonwillbeheavier.Thismeansairintheballoonhasweight.

Air occupies space. Takeaninjectionsyringeandpullthepistonsothatairfillsthesyringetube.Seal

themouthofthesyringewiththehelpofclay.Trytopressthepiston.Doesitgoforward?

Thepistoncannotbepressednowbecauseairhasfilled the space in the syringetube. This shows that air occupies space.

3. Thesandywaterisallowedtostandundisturbedfor15-20minutes.Thesandsettlesdownatthebottomofthecontainer.Thissettledimpurityiscalledsediment.Theclear water above the sediment is poured into another container carefully.Thisprocess is called decantation.

4. Distillation: Intheprocessofdistillation,theimpurewateristakeninaroundflaskandheatedoveraburner.Whenwaterchangesintosteam,theimpuritiesareleftbehind.Thesteamflowsthroughacondenserwhereitconvertsintowateragainandcollects in a container.

ReferFigure12.7onpage112. Evaporation: Itisthesimplestandthesafestwayofpurifyingwaterinourhomes.

Watercontainingimpuritiessuchassaltisheated.Aftersometime,waterchangestosteam,leavingtheimpuritiesbehind.

D. 1. (a) Whentheimpuritiesinaliquidareinsolublebutlightweightsothattheydonotsettledowneasily,thenweusetheprocessofloading.

(b) Filtrationmethodisusedtoseparateinsolubleimpurities.E. 1. Sometimesrockpieces,frozengasesandothersubstancesofthesolarsystemstart

falling towards theearthdue to itsgravity.These startburningas theyenter theatmosphereduetofrictionwithairparticles.Thesearecalledshootingstars.Beforereachingthesurfaceoftheearth,theyburncompletely.Iftheatmospherewasnotthere,thenthesewouldstrikeearth’ssurfaceandformcratersandpits.

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2. 75%oftheearthismadeofwater.Ouroceansarehugewaterreservoirs.However,wemust remember that only 3%of totalwater available on earth is suitable fordrinking.Th us,wemustconservewater.

3. Distilledwateristhepurestformofwaterasitisfreefromallimpuritiesandgerms.Itisusedinlaboratories,medicines,carbatteriesandinjections.


Worksheet 1 1. (a) Chlorine (b) Alum (c) Boiling (d)Oceans (e) Distillation 2. (a) Sedimentationanddecantation Th e settling down of the impurities at the bottom of the container is called

sedimentation while pouring of clean water into a separate container withoutdisturbingthesedimentsiscalleddecantation.

(b) Filtration Th eprocessbywhichinsolubleimpuritiescanberemovedbypassingimpurewater

throughafilterpaper.Worksheet 2 1. (a) Troposphere:Mostcloudsandweatherarefoundinthetroposphere. (b) Stratosphere: In this regionof theatmosphere ispresent theozone layer,which

absorbsmostoftheharmfulultravioletradiationfromtheSun. (c) Mesosphere:Heretheatmosphereisveryrarefied,thatis,thin. (d)Th ermosphere:Th e temperature isquitehot.Spaceshuttleandsatellitemove in

thislayer. (e) Exosphere:Th eexosphereistheregionbeyondthethermosphere.

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Aft er the completion of this chapter, the students will be able to: • describethestructureoftheearth • discussthecompositionofcrust,mantleandcoreoftheearth • appreciatetheroleofthesunasthesourceofallenergy • talkabouttheearth’sonlynaturalsatellite,themoon • diagrammaticallyrepresentthephasesofthemoon • explaintheoccurrenceofsolarandlunareclipses • listtheusesofartificialsatelliteswithexamples

Materials Required

Modelofsolarsystem;videoclippingsonmovementsinspace,occurrenceofeclipses,etc.

Warm Up

Talkabouttheskyinclass.Askthestudentswhichheavenlybodiesareseenduringthedayandwhichareseenatnight.Showthemsomeclippingstomakethetopicmoreinter-estingandboosttheinterestofthechildren.Showthemthesun,planetsandthemoon.NowaskthemtocompletetheexercisegivenintheDelphi’sCornersection.

Concept Explanation

• Earth: Discussthefeaturesoftheearthwhichmakeittheonlyhabitableplanetinthesolarsystem.Recapitulateabouttheinteriorofearth.Explainhowitwasdiscoveredthattheearthisroundinshape.Comparetheearthwiththerestoftheplanetsinthesolarsystem.

• Sun:Encouragestudentstofindoutaboutthefeaturesofthesunfromencyclopaedia.Ask them to readmore about the solar system.List the featuresof the sun.Discussitshugenessandelaborateuponitsimportanceinthesolarsystem.Makethesessioninteractivebyusingalotofamazingfactsandvisualaids.

• Moon:Statethestoryofthefirsteverexplorationtothemoon.Explainthefindingsofastronautsaboutitssurface,gravityandtemperature.AlsodiscussaboutIndia’slunarmissionandChandrayaan.Alsodiscussaboutthedifferentshapesofthemoonintheskyandaskthechildrentoobserveiteveryday.

CHAPTER 13Earth and Heavenly Bodies

89

• Eclipses:Thistopiccanbetaughtwiththehelpofvisualclippings.Talkaboutshadowformation in space. Distinguish between solar eclipse and lunar eclipse. Encouragestudentstodrawdiagramsrepresentingeclipsesintheirnotebooks.

• Artificial satellites: Give ample examples of artificial satellites sent to space. Usephotographsofthesatelliteslistedbyyou.Touchuponthehistoryofspaceexploration.Statetheusesofartificialsatellites.Giveexamplesofdailylifeusesofartificialsatellites.

Reinforce


Explore


90

1. Name the following. (a) Largestplanet ___________________________

(b)Hottestplanet ___________________________

(c) Brightestplanet ___________________________

(d)Planetwithbrightrings ___________________________

(e) Planetnearesttothesun ___________________________

(f) Planetfarthestfromthesun ___________________________

(g) Blueplanet ___________________________

(h)Redplanet ___________________________

(i) Sisterplanetoftheearth ___________________________


(a)

(b)

(c)

(d)

(e)

(f)

(g)

(h)

(i)

WORKSHEET 1

91

1. State whether the following statements are true or false.

(a)Solareclipsealwaysoccursonafullmoonday.

(b)Th efirstmantogotospacewasYuriGagarinofRussia.

(c)Th emoondoesnothaveanyatmospherebecauseof

whichitishitbymeteors.

(d)Th emoonshinesbecauseithasitsownlight.

(e)Artificialsatellitesareusedtodetectacyclonebut

notanupcomingearthquake.


(a)Th eheavenlybodywhichrevolvesaroundanother

heavenlybody. ____________

(b)Th eeventinwhichpathoflightofthesunis

blockedbythemoonortheearth. ____________

(c)Th eemptypartofuniversebeyondtheatmosphere

oftheearth. ____________

(d)Th efirstspaceshipwhichlandedonthesurface

ofthemoon. ____________

(e)Th edarkpartofashadow. ____________

WORKSHEET 2

92


A. 1. (a) Core (b) Moon (c) Artificialsatellites

(d) InternationalAstronomicalUnit (e) Apollo11

2. Th eLargestplanet—Jupiter

Th esisterplanetofearth—Venus

Th eplanetwithrings—Saturn

Redplanet—Mars

Th eblueplanet—Earth

B. 1. Th e reactions taking place between the constituent gases on the sun releasetremendousenergyintheformofheatandlight.Wedependonthisenergyforourlife.Th us,thesunistheultimatesourceofenergy.

2. Artificial satellites are theman-made heavenly bodieswhich revolve around theearth. theyarenot toobig in sizeandare launchedwith somepurpose.Naturalsatellitesoccurnaturally.Th eyarehugesizedandhavenopurposeoruse.

3. Th emoonhasnolifebecauseofthefollowingreasons.

• Th emoondoesnothaveanyatmosphere.Sothereisnooxygenforlivingformsto breathe.

• Th ereisnowateronthemoon.

• Th esideofthemoonwhichfacesthesunisextremelyhot,andtheoneawayfromthesunisextremelycold,asthereisnoairtoreflectorretaintheheatofthe sun.

• Th emoonisoftenhitbyrocksandstonepiecesfromouterspace.Sincethereisnoatmosphereonthemoon,theseobjectsdonotburnbeforereachingthesurface of the moon and thus hit the moon.

4. Th e sun is ahugeball of burninggases. Its inner core consists ofhydrogen andheliumgaseswithtracesofnitrogen.Th eouterlayerofthesunconsistsofmainlyhydrogengas.Th esunalsohasathinatmospherearounditwhichiscalledcorona.

5. Solar eclipse: Th e solar eclipse occurs when the moon comes between the sun andtheearth.Th emoonblocksthepathofsunlightfromreachingtheearth.Th eshadow of the moon is cast on the earth.

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Lunar eclipse: The lunar eclipse occurs when the earth comes between the sun andthemoon.Theearthblocksthepathofsunlightfromreachingthemoon.Theshadow of the earth is cast on the moon.

C. 1. Crust: It is theoutermost layerof the earth. It extends from the land surface to70kminsidetheearth.Itmeansthecontinentsandoceanslieinthecrustoftheearth.Thecrustismadeofrocks,mountains,waterbodiesandsoilparticles.Livingorganismswithinthesurfaceoftheearthsuchasmicroorganisms,animals,etc.livewithin the crust.

Mantle: The layer of the earth under the crust is called mantle. Mantle isapproximately 3000km thick. It is rich in iron andmagnesium. Its temperatureincreasesonproceedingto the lowerpart.Therocks in the lowerpartofmantleare thus,molten.Whenthevolcanoerupts, themoltenmagmacomesout to thesurface.

Core: Coreformsthecentreoftheearth.It isapproximately3500kmthick.It isdividedintotwosub-layers—outercore(2300kmthick)andinnercore(1200kmthick).Outercoreisrichinironandnickel,allinthemoltenform.Innercoreisasolid ball of iron.

2. Lunar eclipse: The lunar eclipse occurs when the earth comes between the sun andthemoon.Theearthblocksthepathofsunlightfromreachingthemoon.Theshadow of the earth is cast on the moon.

ReferFigure13.8onpage123.

3. Solar eclipse: The solar eclipse occurs when the moon comes between the sun andtheearth.Themoonblocksthepathofsunlightfromreachingtheearth.Theshadow of the moon is cast on the earth.

ReferFigure13.7onpage122.

4. (a) The sun is a huge ball of burning gases. Its inner core consists of hydrogenandheliumgaseswithtracesofnitrogen.Theouterlayerofthesunconsistsofmainlyhydrogengas.Thesunalsohasathinatmospherearounditwhichiscalled corona.

Thetemperatureofthecoreofthesunis15billiondegreeCelsius.Itssurfacetemperatureisestimatedtobe60000C.Theimportanceofenergyreceivedfromthesunissummarizedbelow:

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• Plantsutilizethelightofthesuntocarryoutphotosynthesis.

• Th esunlightsuptheworld.

• Heatofthesunprovidesappropriatetemperaturetotheearthforthesurvivalofmanylifeforms.Atnight,thesun’sheatisretainedbytheatmosphereoftheearthwhichkeepstheearthwarm.

Heat of the sun causes evaporation of water from water bodies and results information of clouds and rainfall.

(b) Ever since ancient times, the moon has been a subject of interest amongastronomers.Th efirst spacecraft to landon themoonwasApollo11whichwas launchedbyKennedySpaceCenter,Florida,USAonJuly16,1969.NeilArmstrong,EdwinAldrinandMichaelCollinsfromUSAwerethefirsttosteponthemoononJuly20,1969.Chandrayaan-2isIndia’srecentlunarmissionwhichisgoingtobelaunchedbytheendof2017orbeginningof2018.

D.

Penumbra

Umbra

E. 1. Th e solar eclipse occurswhen themoon comes between the sun and the earth.thishappensonanewmoonday.Th elunareclipseoccurswhentheearthcomesbetweenthesunandthemoon.Th ishappensonafullmoonnight.

2. Th ereisnoatmosphereonthemoon.Soundcannottravelthroughemptyspace.

3. No,asthereisnoatmosphereonthemoon.Th epressurewillnotbeexertedonjuiceto push it up the straw.

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Worksheet 1 1. (a) Jupiter (b) Venus (c) Venus (d) Saturn (e) Mercury (f) Neptune (g) Earth (h) Mars (i) Venus 2. (a) Sun (b) Mercury (c) Venus (d) Earth (e) Mars (f) Jupiter (g) Saturn (h) Uranus (i) NeptuneWorksheet 2 1. (a)F,(b)T,(c)T,(d)F,(e)T 2. (a)Satellite (b) Eclipse (c) Space (d)Apollo11 (e) Umbra

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Aft er the completion of this chapter, the students will be able to: • distinguishbetweenluminousandnon-luminousobjects • performactivitytodemonstraterectilinearpropagationoflight • giveexamplesofopaque,translucentandtransparentobjects • listconditionsnecessaryfortheformationofshadows • explainthefeaturesofshadows

Materials Required

Samplesoftransparent,translucentandopaqueobjects

Warm Up

Talkinclassabouthowweseethebeautifulworldaroundus.Askthestudentswhatwouldhappenifitwassuddenlydark.Tellthemwecanseethingsaroundusonlywhenthereislight.Encouragethemtotellwheredoesthelightcomefrom.Describethoseobjectsasluminousobjects.NowaskthemtoreadandcompletethetaskgivenintheDelphi’sCornersection.

Concept Explanation

• Objects and light: Providethesamplesoftransparent,translucentandopaqueobjectstothestudents.Askthemtoseethrougheachofthem.Letthemtocommentthatthroughwhichobjectstheycanseeclearly.Th enclassifytheobjectsastransparent,translucentandopaque.Askthestudentstogivemoreexamplesofobjectsintheirsurroundingswhicharetransparent,translucentandopaque.Discussthatairistransparent.Th uswecanseeclearlythroughit.

• Shadow and its features:Performanactivitytodemonstratetheformationofshadowofanopaqueobjectinclass.Th eclasscanalsobetakenoutinthesuntoseeshadowformation.Tell thestudents that shadowis formedwhenanopaqueobject isplacedbetween a source of light and the screen.Discuss the parts of shadow—umbra andpenumbra.Motivatethestudentstothemselvescomeupwiththefeaturesofshadow.Askthemtocomparetheirshadowinthesuninthemorningandatnoon.Discussthereasonforthisobservation.

CHAPTER 14Light and Shadows

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Explore


98

1. Fill in the blanks. (a)____________enablesustoseetheobjectsaroundus.

(b)A piece of glass is ______________while a piece of cardboard is____________.

(c)Objects that allow light to pass through them partially are called______________.

(d)______________ and _____________ are examples of luminousobjects.

(e)______________and_____________areexamplesofnon-luminousobjects.

2. Give one word answer for the following. (a)Darkspotformedbyanopaqueoratranslucentobject.__________

(b)Shadowisshortestatthistime. __________

(c)Typeofobjectwhichdoesnotcastashadow. __________

(d)Asourceoflightfortheearth. __________

3. Write the condition necessary for the formation of a shadow.

_______________________________________________________

_______________________________________________________

_______________________________________________________

_______________________________________________________

WORKSHEET 1

99

1. Write two examples of each of the following. (a)Transparentobject __________ __________

(b)Translucentobject __________ __________

(c)Opaqueobject __________ __________

2. Write the features of a shadow.

_______________________________________________________

_______________________________________________________

_______________________________________________________

_______________________________________________________

3. Defi ne the following.

(a)Shadow

_______________________________________________________

_______________________________________________________

(c)Opaqueobject

_______________________________________________________

_______________________________________________________

WORKSHEET 2

100


A. 1. (a) F (b) T (c) T (d) F 2. Glasstumbler—Transparent Tissuepaper—Translucent Longestshadow—Evening Cardboard—OpaqueB. 1. Th erearefollowingpropertiesofshadows: • Th eshadowofanobject is formed in thedirectionopposite to thesourceof

light. • Whenthesourceoflightorobjectmoves,shadowalsoshiftsaccordingly.

• Th e lengthofthe shadowchanges if thedistancebetweenthe source and the objectchanges.

2. Soundcantravelthroughthewallbutlightcannotpassthroughthewallaswallisanopaqueobject.Itcompletelyblocksthepathoflight.

3. Shadowisthedarkregionorshadecastbyanobjectbehinditwhenitiskeptinfrontofasourceoflight.Itisformedbecauseitobstructsthepathoflightcomingfrom the source.

4. Weneedasourceoflight,anopaqueobjecttoobstructthepathoflightandascreenon which shadow will be formed.

5. Th e items to be sold are placed in transparent cases so that customers can see them easily.

C. 1. Whenlightcomingfromasourcefallsonasurface/object,threethingsmayhappen: • Allthelightcanpassthroughtheobject • Someofthelightmaypassthroughtheobject • Nolightcanpassthroughthematerialatall 2. Transparent object Translucent object Opaque object

Objectwhichallowstotaltransmissionoflight.

Objectwhichletspartialtransmissionoflightthroughit.

Objectwhichdoesnotletlighttotransmitthroughit.

Examples:Air,waterandglass

Examples:Oilpaper,butter paper and tissue paper

Examples:Metals,bricksand cardboard sheet

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3. Ourshadowinthesunisverylonginthemorning.Th isisbecausethesunisnearthehorizon,andveryfarfromus.Th esizeoftheshadowdecreasestillnoonwhenthesunreachesoverhead.Th eshadowisshortestatnoon.Th ereafterthelengthoftheshadowstartsincreasingandbecomesthelongestintheeveningwhenthesunisagainnear thehorizonbeforesunset. Intheafternoon, theshadowfalls inthedirection opposite to that in the forenoon.

4. Ashadowhasthefollowingfeatures. • Th eshadowofanobjectisformedinthedirectionoppositetothesourceoflight. • Whenthesourceoflightorobjectmoves,theshadowalsomovesaccordingly. • Th elengthoftheshadowchangesifthedistancebetweenthesourceoflightand

theobjectischanged.D. 3inevening; 1inmorning; 2atnoonE. 1. Whenlightenterstheatmosphereoftheearth,itisscatteredbyairparticles.Th ere

isnomediuminspacetoscatterlight.Soitisdarkinspace. 2. Th is isbecausetheyareata largedistancefromtheearth.Asthedistanceofthe

object from the surface increases, the umbra becomes smaller and smaller andfinallyvanishes.


Worksheet 1 1. (a)Light (b) transparent,opaque (c) Translucent (d) Sun,stars (e) Wood,table 2. (a) Shadow (b) Noon (c) Transparent (d) Sun 3. Asourceoflight,atranslucentoranopaqueobjectandasurfaceonwhichtheshadow

is formed.Worksheet 2 1. (a) Air,water (b) Butterpaper,oilpaper (c) Metal,brick 2. Th e shadowof anobject is formed in thedirectionopposite to the source of light.

When the sourceof lightorobjectmoves, the shadowalsomoves accordingly.Th elengthoftheshadowchangesifthedistancebetweenthesourceofthe0lightandtheobjectischanged.

3. (a) Th edarkspotformedbyanopaqueoratranslucentobjectwhenitblockslightiscalled a shadow.

(b)Th eobjectsthatdonotallowlighttopassthroughthemarecalledopaqueobjects.

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Aft er the completion of this chapter, the students will be able to: • discussaboutthecausesofnaturalcalamities • explainhowhumanactivitiesareresponsibleintriggeringnaturalcalamities • practisewaystoprotectthemselvesfromnaturalcalamitiesthroughmockdrills • reflectupontheeffectsofnaturalcalamities

Warm Up

Talkabouttherecentincidentsofearthquake,tsunami,volcaniceruptions,etc.Tellthestudentsaboutthemassivelosstolifeandpropertycausedbytheseifwearenotalert.Showvideosandnewsclipsabout theseevents.Createan interest inclassabout theseincidencesandexplainhowtheseareharmful.AllowthemtocompletethetaskgivenintheDelphi’sCornersection.

Concept Explanation

• Earthquake: Th estudentscanbetakentotheMetrologicalCentrewheretheycanbeexplainedabouttheoccurrenceofearthquakeandmeasurementofitsintensity.Explainaboutthetectonicplateswhichconstitutetheearth.Tellthestudentshowearthquakesaremore frequent in seismiczones. Ifpossible, conductadisastermanagementdrillinschool.Th iswillhelpthemunderstandabouttheprecautionstobetakenduringanearthquake.

• Tsunami:Discussthetsunamiof theIndianOceanin2004andtsunami inJapanin2011.Discusstheeffectsoftsunamiandsafetymeasurestobetakenforprotectionfromthese eff ects.

• Volcano:Discussthetypesofvolcanoesandgiveexamplesinclassaboutwheretheyarelocated.Askstudentstolocatethedifferenttypesofvolcanoesonaphysicalmapoftheworld.Drawacross-sectionofavolcanoandlabelitsparts.

Reinforce


CHAPTER 15Natural Disasters

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Explore


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1. Identify the following disasters and give one example each of their occurrence in the past.

(a)

_______________________

(b)

_______________________

(c)

_______________________

WORKSHEET 1

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WORKSHEET 2

1. Label the parts of the volcano.

(b)

(c)

(d)

(a)

2. What does a disaster management kit constitute?

_____________________________________________________

_____________________________________________________

_____________________________________________________

_____________________________________________________

_____________________________________________________

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A. 1. (a) Focus (b) Aftertremors (c) Seismogram (d) Earthquake (e) Volcaniceruption 2. (a) lava,ashes,hotgases (b) tides (c) drop,cover,hold (d) tsunami (e) mountFuji

B. 1. ReferFigure15.2onpage135.

2. Atsunami issaid tooccurwhenhugevolumeofwater isdisplaced in theoceanwhichgenerateslargewaves.Th edisplacementiscausedbyanearthquake,volcaniceruption,landslideoranunderwaterexplosion.

3. Followingaresomeoftheeffectsofanearthquake. • Shakingofbuildings,materialsinbuildings • Fallingofobjectskeptonhighshelvesandinjuriestopeoplebeneath • Fallingofbuildingsandtrees,resultinginlossoflifeanddestruction 4. Th etsunamicanbepredictedinadvance.Th efishermenandtouristsaremadeto

evacuatethebeachandseasimmediately.Th eboatsaretakenaway.Animalsandpeoplearetakentosafeplaces.Th isispossibleonlybyfollowingthewarningsandinstructionstelecastbyauthorities.

5. Th reetypesofvolcanoesareactivevolcano,dormantvolcanoandextinctvolcano.C. 1. Th eoutermostlayeroftheearthcalledcrustisactuallymadeoftwelvehugeslabsof

rockscalledtectonicplates.Th etectonicplatesarefittogetherlikeajig-sawpuzzle.Th eseplatesareslightlyinmotionallthetime.Sometimes,thetwoplatesmaybrushoroverlapeachotherattheirboundaries.Atthistime,therocksgetdisplacedandshaking(calledtremors)begin.

2. Avolcanoisamountainwhichopensdownwardsintoapoolofmoltenrocksbelowthe surface of the earth. Under the crust of the earth, the temperature of the earth is veryhighoverthefloorofmantle.Whentheoceanplatesandthelandplatescollide,theoceanplatesubmergesunderthelandplate.Wateroverthatplateisreleasedup.Th islowersthetemperatureofthemantleandformsmagma.Th isforms‘magmachambers’whichcontainhotgases,ashesandmoltenrockcalledlava.

3. Tsunami has drastic eff ects on the areas where it hits. Some eff ects of tsunami are as follows:

• Itsubmergesthelowlyingcoastalareas • Highspeedwindsalongwithlargeamountofwateranddebrisdestroytrees,

buildings,bridgesandshipscompletely.

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• Humanbeingsandanimalsaresmashedbywater. Itisdifficulttoescapeatsunami.Butthetsunamicanbepredictedinadvance.Th e

fishermenandtouristsaremadetoevacuatethebeachandseasimmediately.Th eboatsaretakenaway.Animalsandpeoplearetakentosafeplaces.Peopleareappealednottopanicandfollowthewarningsandinstructionstelecastbyauthorities.Th eelectricitysupplyoftheregioniscut.

4. • Active volcanoes: Th esevolcanoescaneruptanytimeastheyremainactive.Forexample,MountFuji(tallestmountaininJapan)andMountErebus.

• Dormant volcanoes: Th esevolcanoeshavenoteruptedforseveralyearsbutcaneruptanytime.Forexample,MountKilimanjoroinTanzaniaandNarcondaminAndamansaredormantvolcanoes.

• Extinct volcanoes:Th esevolcanoesareextinctantarenotexpectedtoeruptinfuture.Forexample,ZuidawlvolcanoinNetherlandisanextinctvolcano.

D. Armedforcesconducttherescueoperationintheeventofanaturaldisaster.Th eytakethehelpofhelicopters,boatsandrelevantvehiclestomovethepeopletosafeplaces.Th eyprovidemedicalhelptopeopleinrescuecamps.Th eyalsosupplyfoodand water to aff ected people.

E. 1. Th eelectricitysupplycouldbecutoffandthepersonwouldremainstruckinthelift.Alsothebuildingcouldbedamagedandliftbejammed.

2. No,atsunamiisgeneratedduetoearthquake,underwaterexplosionoranyothersudden disturbance in the ocean.

3. Th ehotgasesandlavafilltheairwithashes.Lavadamagestheforestsandharmsanimalsandproperty.


Worksheet 1 1. (a) Tsunami:InJapanin2011(b)Earthquake:InNepalin2015 (c) Volcanoeruption;MountOntakeinJapanin2014Worksheet 2 1. (a) Lava (b) Crater (c) Vent (d)Magma 2. Afirstaidkit Cannedfood Canopener Packagedwater Battery-operatedradiotolistentotheupdates Helmetandstick

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Answers to Summative Assessment 2

A. 1. Energy 2. Coal 3. Soilerosion 4. Gravitational 5. More 6. Moon 7. Saturn 8. Seismogram 9. Noon 10. TranslucentobjectB. 1. Lightandheatenergy 2. Mechanicalenergy 3. Electricenergy 4. Mechanicalenergy 5. WindenergyC. ReferFigure13.2onpage118.D. 1. Asourceof light,a translucentoranopaqueobjectandasurfaceonwhichthe

shadow is formed. 2. Tidalwavesare theriseandfallof theseawavesdueto thegravitational forces

acting between the sun, themoon and the earthwhile tsunamioccurswhen ahugevolumeofwaterisdisplacedintheoceanduetounderwaterearthquakeoranexplosion.

3. Itisasimplemachinewithaflatsurface,oneendofwhichishigherthantheother. 4. Solar eclipse occurs when the moon comes in between the sun and the earth while

lunar eclipse occurs when the earth comes in between the sun and the moon. 5. Advantages:Someadvantagesoffrictionareasfollows. •Frictionenablesustowalk.Itisdifficulttowalkonasmooth,polishedfloorasit

offerslessfriction.Th us,therearemorechancesofourslippingonsuchsurfaces. •Frictionenablesustowriteonthepaperorontheblackboard. •Screwsaretightenedduetofrictionbetweenthenutandthescrew. •Tyresofvehicleshavespecialgroovestoincreasefrictionbetweenthetyresand

theroadsothattheycangriptheroadeasily. 6. Water: When it rains heavily, the rivers get flooded. Flood water enters the

agricultural lands. Th e flowing water washes away the fertile top layer of soilwithit.Waterflowingdownhillwashesthetopsoilfromthehillslopes.Th issoilaccumulates in rivers and changes their course. RiverKosi, Bihar, caused greatdestructionin2008duetothisreason.

Wind:Inregionswherethereisverylittlevegetation,windsandstormsblowawaythefertilelayerofthesoil.Th isreducesthecropyield.

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E. 1. Artificialsatellitesareman-madeobjectsthatrevolvearoundtheEarth.Aryabhatawas thefirst Indianartificial satellite, launched in1975.GSAT-6,alsoknownasINSAT-4E,isanartificialsatellitewhichwaslaunchedonAugust27,2015.Itisacommunication satellite.

Uses of Artificial Satellites:Artificialsatellitesareusedforresearchofheavenlybodies,forcommunication,forweatherforecastingandtostudyourplanetEarth.

2. Weathering is a very slow process. Due to the heat of the sun and cooling atnight,therocksexpandandcontract.Becauseofthiscontinuousexpansionandcontraction,cracksdevelopintherocks.Whenrainwaterseepsintothecracksoftherocks,thewaterfreezesintoice.Itcausestherocktocrackfurther.Thisprocessrepeatsitselfagainandagaintilltherockbreaksdownbythepressureexertedbyice.Riverscarrythesebrokenpiecestofaroffplaces.Thesepiecesbrushagainsteachothertilltheybecomesmallerandsmallerandfinallyformsoil.Rockparticlesbecomeevenfinerbytheactionofwind.Thesoilgetsdepositedontoplainswhenriverscarrythemalong.

ReferFigure10.3onpage88. 3. ReferFigure11.1onpage95 4. Toprotectoneselffromtheeffectsofearthquakes,oneshouldtakethefollowing

precautions. •Buildingsshouldbeengineeredinsuchawaythattheyarequakesafe. •As the tremors begin, people should evacuate the building immediately and

movetoopenspaces. •Oneshouldnotuseescalatorsandlifts. 5. Transparent Objects: Theobjectsthatallowlighttopassthroughthemcompletely

are called transparent objects. Air, water, glass and some types of plastics areexamplesoftransparentobjects.

Translucent Objects: Theobjectsthatallowlighttopassthroughthempartiallyarecalledtranslucentobjects.Groundglass,butterpaper,oilpaperandtissuepaperareexamplesoftranslucentobjects.

Opaque Objects: Theobjects that do not allow light to pass through them arecalledopaqueobjects.Cardboardsheet,metals,bricksandwoodenplankaresomeexamplesofopaqueobjects.

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F. 1. Thesoilprofileconsistsoffourmainhorizons:O,A,BandC. Horizon O: Humus: Thisisthetopmostlayerofthesoil,whichisusuallycomposed

ofdecomposedmatter suchasplant andanimal remains (humus).This layer isquitedarkandthin.Itisveryfertilebecauseofthepresenceofhumus.

Horizon A: Topsoil: Thetopsoilmainlyconsistsofveryfineparticlesofclayandsand.Italsocontainsalotoforganicmatter.Alsoarepresentlargequantitiesofnutrientswhichmakethesoilfertile.Plantsgrowinthislayerofthesoil.

Horizon B: Subsoil: The subsoil occurs beneath the topsoil. It contains gravel,rocksandstones thatareof largersize thantheparticlesof topsoil. Ithassmallamountofhumusinit.Itallowswatertoseepthroughit.

Horizon C: Regolith: It consists of small pieces of rocks that are present deepinsidetheearth.Theserocksdonotallowwatertoseepthroughthem.Bedrockisfoundbeneaththislayerandcontainslargerockpieces.

Refer10.2onpage87. 2. Light Energy:Lightisaformofenergywhichhelpsustoseethingsaroundus.The

sourcesoflightinoursurroundingsaresun,bulbs,candles,firefliesandtubelights. Sound Energy: Soundenergyenablesustohear.Thesourcesofsoundareaudio

players,instruments,televisionandspeakers. Mechanical Energy: Theenergypossessedbyanobjectduetoitsmotion(kinetic

energy)ordue to itsposition (potential energy), is calledmechanical energy.Amovingcar,ahangingchandelierandarollingfootballpossessmechanicalenergy.

Electrical Energy: We use electrical energy to operate countless appliances athomes.Electricalenergyisgeneratedatpowerstation.Itisproducedintheformofelectric current.

Wind Energy: Theenergyofmovingaircanbeusedtorotateawindmill.Whenthewindmillrotates,itgenerateselectricity.

Solar Energy: Thesunistheultimatesourceofenergyontheearth.Solarenergyismainlyavailabletousintheformofheatandlight.Weconvertsolarenergyintoelectricalenergyusingasolarcell.

Heat Energy: Heat energy isneeded to getwarmth, to cook foodand to runavehicle.HeatenergyisobtainedfromthesunandalsobyburningfuelssuchasLPG,wood,coal,petrolandkerosene.

111

3. Taketwoballoonsandinflateoneofthem.Takearodandwiththehelpofastringtiethedeflatedballoonononesideandtheinflatedballoonontheotherside.Holdtherodfromthecentre.Thesidewhichholdstheinflatedballoonwillbeheavierand will tilt. This proves that air has weight.

Takeanemptyplasticbottleandfillitwithwateruptothebrim.Closethemouthofthebottletightlywithalid.Prickasmallholeinthecentreofthebottlesothatwaterstartsflowingoutofthebottle.Aftersometime,theflowofwaterfromtheholewillautomaticallystopthoughthereisstillalotofwaterinthebottle.Nowloosenthelidofthebottle.Thewateragainstartsoozingoutofthehole.Thisshowsthatwhenwaterwasremoved,therewasnotenoughairtopushmorewateroutofbottle. As the lid was loosened, air entered the bottle and pushed the water out of the bottle. This shows that air exerts pressure.

4. Insoluble impurities are separatedbyfiltration and sedimentationwhile solubleimpuritiesareremovedbyevaporationanddistillation.

5. Basedonthepositionoftheload,fulcrumandeffort,leversareclassifiedintothreetypes.

Class I levers: TheleversinwhichthefulcrumislocatedbetweentheloadandtheeffortarecalledclassIlevers.Examplesarepliersandapairofscissors.

Class II levers: TheleversinwhichtheloadislocatedbetweenthefulcrumandtheeffortarecalledclassIIlevers.Examplesareawheelbarrow,anutcrackerandabottle opener.

Class III levers: TheleversinwhichtheeffortislocatedbetweentheloadandthefulcrumarecalledclassIIIlevers.Examplesareastapler,apairoficetongsandafishingrod.

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Model Test Paper 2 50 marks

A. Fill in the blanks. (1 × 5 = 5) 1. Inlever,a____________isthejointofsupportaroundwhichtherod

moves. 2. ____________prevents theflowof the fertile soil alongwithwater

downhill. 3. Thethinlayerofatmospherearoundthesuniscalled____________. 4. Cardboardsheetisan____________object. 5. MountKilimanjaroinTanzaniaisa____________volcano.

B. Match the following. (1 × 5 = 5) Seismograph Solubleimpurities Distillation Fluorescentlamps Slide Earthquake Liftingabucket Inclinedplane Argon Muscularforce

C. Write any two examples of each of the following. (1 × 5 = 5) 1. Artificialsatellite 2. Mechanicalenergy 3. Wheelandaxle 4. Activevolcano 5. Methods used to separate soluble impurities

D. Answer the following briefly. (2 × 5 = 10) 1. Explaintheoutermostlayeroftheearth. 2. Write the steps to be followed in water treatment plants. 3. Whatwillbethelengthoftheshadowwhenthedistancebetweenthe

sourceoflightandtheobjectdecreases?

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4. Whatisthedifferencebetweenextinctanddormantvolcanoes? 5. Howmanypartsdoesaleverhave?Namethem.

E. Answer the following in detail. (3 × 5 = 15) 1. Whatarethetypesofenergy?Explainthelawofconservationofenergy. 2. Writeanyfivemethodsforsoilconservation. 3. Writeanactivitythatshowsairexertspressure. 4. Explainsolareclipse. 5. Explainthelengthofashadowduringaday.

F. Look at the given picture carefully and answer the following questions.

(3 + 3 + 4 = 10)

1. Labelthegivenpicture. 2. Whichtypeofsimplemachineisit? 3. Drawapictureofanexampleofsimilartypesofmachine.

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Answer to Model Test Paper 1

A. 1. Temperature 2. Magma 3. Sprain 4. Expansion

5. Backbone 6. Brain,spinalcord 7. Blowholes 8. Moulting

9. Iodine 10. Fruitexplosion

B. Mass-Kilogram

Obsidian-Igneousrock

Contraction-Cooling

Spinalcord-Reflexaction

Flippers-Penguins

C. 1. F 2. T 3. F 4. T 5.T

D. 1. Gapsareleftbetweentherailsoftherailwaytrack.Insummer,themetalrailsexpandandincreaseinlength.Thisfillsthegap.Ifnogapsareleft,thentherailswillgetdeformed in summer heat.

2. Ittheburnsaresevere,covertheburntareawithacleancotton.Ifblistersareformedontheburntarea,theyshouldnotbepricked.Thevictimshouldbeimmediatelyrushed to a doctor.

3. Someactionsarecarriedoutbyourbodyasasuddenandautomaticresponsetoanevent.Theseactionsarecalled reflexactions.Theseactionsarevery fast.Themessageisreceivedandsentbythespinalcordonly;thebrainisnotinvolved.Forexample,ifyouaccidentallyputyourhandoveracandle,yousuddenlymoveyourhandaway.

4. Skull:Itprotectsthebrain.

Ribcage:Itprotectstheheartandthelungs.

5. Roughageaddsbulktothefoodandhelpsindigestion.Itpreventsconstipationandalsohelpsinbowelmovements.Itkeepsourdigestivesystemhealthy.

E. 1. Air:Whenaninfectedpersonsneezesorcoughs,germsarereleasedintotheair.Ahealthypersoncanget infectedby thesegerms.Commoncold, influenzaandchickenpoxspreadinthismanner.

Food and water:Fliessitonuncoveredfoodandtransfergermstothefoodwhichcaninfectahealthypersonwhenhe/sheeatsthisfood.Drinkinguncleanwateralso

115

causes thespreadofcertaindiseases.Cholera, typhoidand jaundicearediseasesthat spread in this manner.

Vectors (animals/insects): Some insects transmit disease-causing germs from asickpersontoahealthyperson.Theseinsectsarecalledvectors.Malariaisspreadthroughthebiteofmosquitoesthatcarrythediseases-carryinggerms.Thebiteofaninfecteddogspreadsadiseasecalledrabies.

2. Dispersal by wind:Seedsofsomeplantsarelightweightandarehairyandwinged.Theseseedscanbeeasilycarriedawaybywind.Examplesaredandelion,cottonandmadar.

Dispersal by water: Someplants have spongy seeds or seedswithfibrous outercovering,which helps these seeds stay afloat inwater.Water carries these seedsto largedistances.Examplesof suchplants are lotus (spongy seed) and coconut(fibrousoutercoveringontheseed).

3. Marble is formed from limestone. The Taj Mahal, one of the most beautifulmonuments,ismadeofwhitemarble.Itiswidelyusedinmakingfloors,statuesandornamentalobjects.Itshinesonbeingpolished.

Quartziteismadefromsandstoneandcontainshighpercentageofquartzmineral.Itisanextremelyhardrock.Itfindswideapplicationinglassandceramicindustries.Itisalsousedinmostofthewatchesandjewellery.

4. Hinge joint:Asthenamesuggests,thistypeofjointworkslikeahingeinadoor.Thismeansthebonescanmoveinonedirectiononly.Forexample,theelbow,knee,fingersandtoes,allhavehingejoints.

Gliding joint:Thetypeofjointwhichallowsthebonestoglideovereachotheriscalledtheglidingjoint.Itisfoundinthewristandankle.

5. Adesertisadry,sandyandhotplacethatreceivesverylittlerainfall.Itisusuallyhotduringthedayandcoldduringthenight.Animalssuchascamel,ratandsnakearefound here.

Mountainsandhillyregionshavearockysurfaceandcoldclimate.Snowfalloccursintheseregionsinwinters.Animalssuchassnowleopard,mountaingoatandyakare found here.

F. 1. Fishmoveswiththehelpoffins.

2. Fishbreathewiththehelpofgills.

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Answer to Model Test Paper 2

A. 1. Fulcrum 2. Terracefarming 3. Corona

4. Opaque 5. Dormant

B. Seismograph-Earthquake

Distillation-Solubleimpurities

Slide-Inclinedplane

Liftingabucket-Muscularforce

Argon-Fluorescentlamps

C. 1. Aryabhata,INSAT-4E

2. Amovingcar,Ahangingchandelier

3. Acarsteering,adoorknob

4. MountFuji,MountErebus

5. Distillation,Evaporation

D. 1. ItistheoutermostlayerofEarth.Ithaseverythingthatisessentialforlife.Continentsandoceanslieinthislayer.Itsthicknessvariesfrom5kmto70km.Itismadeofrocks.

2. Watersuppliedtoourhomesistreatedbydifferentmethodsofpurificationsothatitbecomesfitforuse.Followingstepswillhelpyouunderstandhowwateristreatedin treatment plants.

Sedimentation:Waterfromtheriveriscollectedinahugesedimentationtankandis allowed to stand undisturbed.

Filtration: After the larger-sized impurities settle down, they are removed.Thefiner-sizedimpuritiesareremovedbyfilteringthiswater.Thewaterisallowedtoflowthroughhugesievesforthispurpose.

Chlorination: Water is disinfected by adding chlorine. This process is calledchlorination.Potassiumpermanganateisalsousedtopurifywater.Cleanwaterissupplied to our homes.

3. Thelengthoftheshadowwillincreasewhenthedistancebetweenthesourceoflightandtheobjectdecreases.

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4. Dormant volcanoes:Thesevolcanoeshavenoterupted for severalyearsbutcaneruptanytime.Forexample,MountKilimanjaroinTanzaniaandNarcondaminAndamansaredormantvolcanoes.Extinct volcanoes:Thesevolcanoesareextinctandarenotexpectedtoeruptinfuture.Forexample,ZuidwalvolcanoinNetherlandisanextinctvolcano.

5. A leverisarigidrodthathelpsustoliftandmovesomethingwithlesseffort.Aleverhas three main parts.

Fulcrum (F):Itisthejointofsupportaroundwhichtherodmoves.

Load (L):Itistheobjectthathastobemoved.

Effort (E):Itistheforcethatneedstobeapplied.

E. 1. Lightenergy,soundenergy,mechanicalenergy,electricalenergy,windenergy,solarenergyandheatenergyare the typesofenergy. It shouldbenoted that the totalenergypresentintheuniverseisconstant.Thismeansthatenergyisneithercreatednordestroyed.Energyonlygetsconvertedfromoneformtoanother.

2. Deforestationorlarge-scalecuttingoftreesshouldbeprevented.Treespreventsoilfrombeingeroded.Overgrazingbycattleshouldbecontrolled.Whenthecropsareharvested,farmersshouldgrowcover cropssuchasgrassandcreeperstopreventsoilerosionbywind.Alongtheriverbanks,embankments shouldbebuilt.Duringrains,farmersshouldbuildbundsalongtheboundaryoftheirfieldstopreventthefertiletopsoilfromflowingawaywithrainwater.

3. Takeanemptyplasticbottleandfillitwithwateruptothebrim.Closethemouthofthebottletightlywithalid.Prickasmallholeinthecentreofthebottlesothatwaterstartsflowingoutofthebottle.Aftersometime,theflowofwaterfromtheholewillautomaticallystopthoughthereisstillalotofwaterinthebottle.Nowloosenthelidofthebottle.Thewateragainstartsoozingoutofthehole.Thisshowsthatwhenwaterwasremoved,therewasnotenoughairtopushmorewateroutofbottle.Asthe lid was loosened, air entered the bottle and pushed the water out of the bottle. Thisshowsthatairexertspressure.

4. AsolareclipseoccurswhenthemooncomesinbetweentheSunandtheEarth.ItblocksthesunlightfromreachingtheEarthandcreatesashadow.Asolareclipsemaybetotalorpartial.Inatotalsolareclipse,theSunisnotvisibleatall.Inapartial

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solareclipse,apartoftheSunisvisible.Th emoon’sshadowhastwoparts:umbraandpenumbra.Th eregionontheEarthwheretheumbrafalls,willhaveatotalsolareclipsewhile thepartwhere thepenumbra falls,willhaveapartial solareclipse.Solareclipseoccursonlyduringthedaytimeonanewmoonday.

5. In the morning: Our shadow is long in the morning. Th e size of the shadowdecreasestillnoonwhenthesunreachesoverhead.

At noon: Th e shadow is the shortest at noon.

In the evening:Th ereafter,thelengthoftheshadowstartsincreasingandbecomeslongagainintheevening.

F. 1. F

E

L

2. ItisaclassIIIleverbecauseinthistheeffortislocatedbetweentheloadandthefulcrum.

3.

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