SCIENCE(Practiceworksheet) Class–9th Term2(2013‐14) PHYSICS Q1.DescribeThrust.WriteitsSIunit. Q2.AblockofmassmisraisedfrompositionAtoBbytakingtwodifferentpartsasshown. LettheheightAB=h.Answerthefollowingquestions. A A hh B Fig1 B Fig2 a)WhatistheworkdoneontheblockinFig1andFig2. b)NametheenergypossessedbytheblockatpositionBinboththecases. Q3.a)Anelectricheaterisrated200W.Howmuchenergydoesitusein5hours. b)EstablishtherelationbetweenthecommercialunitandSIunitofenergy. Q4.Giveanexampleeachofthefollowingenergytransformation a)HeatenergyintoMechanicalenergy. b)MechanicalenergyintoElectricenergy. Q5.Thekineticenergyofanobjectmovingwithavelocityof5m/sis25J.Findthemassofthe object.Whatwillbeitskineticenergywhenitsvelocityis2times?Justifyyouranswer. Q6.Whatismeantbypowerofmachinefroma20mhighfallnearly25Metrictonnesofwaterfall persecond.Calculatetheequivalentpowerifallthisenergyisutilised?(g=10m/s2) Q7.Statethemeaningof1Pascal.Aboyofmass40kgisstandingonloosesand,iftheareaofhis Feetis0.04m2.Calculatethepressureexertedbytheboy. Q8.Distinguishbetweenpositiveandnegativework.Whenyouliftanobject,twoforcesactonit. Identifytheseforces. Q9.Statethedifferencebetweendensityandrelativedensity. Q10.Definethefollowingterms.StateitsSIunit. a)Wavelengthb)Timeperiodc)Amplitude. CHEMISTRY Q1.Watermoleculehashydrogenandoxygenintheratioof1:8bymass.Findtherationumberof atomsinthemolecule. Q2.a)DrawadiagramshowingtheobservationsmadebyRutherfordinalphaparticlesscattering experiments. b)WhydidRutherforduseagoldfoiltheexperimentmentionedinpart(a)? c)ListthreeconclusionsdrawnbyRutherfordfromhisexperiment.Statethreefeaturesofnuclear modelofanatomputforwardbyRutherford. Q3.a)StatethelimitationsofJ.J.Thomson’smodelofanatom. b)Definevalencybytakingtheexamplesofmagnesium(At.No:12)andoxygen(At.No:8). c)DescribeBohr’smodelofatom. Q4.a)Calculatethenumberofparticlesineachofthefollowing: i)46gofNaatomsii)8gofO2moleculeiii)0.1moleofcarbonatoms. b)Convertfollowingintomole: i)12gofO2gasii)20gofwateriii)22gofCO2 Q5.a)Givetherelationshipbetweenmole,massandAvogadro’snumber. b)Writethechemicalformulaofthefollowingcompounds: i)Hydrogennitrideii)Hydrogenperoxideiii)Hydrogencarbide iv)Calciumfluoridev)Iron(II)bromidevi)SilverIodide vii)Ammoniumcarbonateviii)Bariumsulphateix)Calciumphosphate Q6.a)Calculatethemolecularmassesofthefollowingcompounds: i)Aceticacid(CH3COOH)ii)Ethanol(C2H5OH)iii)Carbondioxide b)Calculatethemassofthefollowing: i)0.5moleofN2gas(massfrommoleofmolecule) ii)0.5moleofNatoms(massfrommoleofatom) iii)3.011×1023numberofNatoms(massfromnumber) iv)6.022×1023numberofN2molecules(massfromnumber) c)Calculatethenumberofparticlesineachofthefollowing: i)46gofNaatoms(numberfrommass) ii)8gofO2molecules(numberofmoleculesfrommass) iii)0.1moleofcarbonatoms(numberfromgivenmoles) Q7.a)Whichofthefollowingweighsmost? i)32gofoxygenii)2.0gofatomsofnitrogen iii)0.5moleofironiv)3.011×1023atomsofC. b)Calculatethenumberofatomsineachofthefollowing:(at.masses:H=1,S=32,Fe=56) i)0.08gofhydrogenii)0.008gofsulphuriii)0.8gofiron. Q8.a)Writethenamesofthefollowingcompounds: i)Ca3N2ii)Mg(HCO3)2iii)(NH4)2CO3 iv)Zn3(PO4)3v)Al2(SO4)vi)FeCl3 b)TheaverageatomicmassofasampleofanelementXis16.2u.Whatarethepercentagesof isotopes16X8and18X8inthesample. c)ElementsA,B,CandDhaveatomicnumbers11,8,1and17respectively.Givethechemicalfor formulaeofthecompoundsformedbetween(i)AandD(ii)BandC. Q9.SubstancesfromAtoEhaveinthem,thedistributionofelectrons,neutronsandprotonsas follows: Substance Electrons Neutrons Protons A B C D E 4 8 18 17 17 4 9 22 20 18 3 9 18 17 17 Makinguseofthesedatafind(i)acation(ii)ananion(iii)apairofisotopes(iv)anatomofnoblegas. Q10.a)ThenuclearcompositionoftwoatomicspeciesXandYisasfollows: X:17Protons,18NeutronsY:17Protons,20Neutrons Whataretheir(i)atomicnumbers(ii)massnumbers?Whatistherelationbetweenthesetwo Atomicspecies?Nametheelementorelementswhichtheyrepresent. b)Anatomhaselectronicconfigurationof2,8,7: (i)Whatistheatomicnumberoftheelement? (ii)Whichofthefollowingelementshavesamenumberofvalanceelectrons? N(7),F(9),P(15)andAr(18) BIOLOGY Q1.Writeanoteonhowforestinfluencesthequalityofourair,soilandwaterresources. Q2.Differentiatebetweenphanerogamsandcryptogams. Q3.a)Definenomenclature.Givethescientificnameforpeacock. b)Whointroducedthebinominalnomenclature?Enlisttherulesorconventionsfollowed whilewritingthescientificnames. Q4.Giveoneuseoflichens. Q5.ExplainhowHIVAidsvirusaffectsanddamagesourbody? Q6.WhywhalesarenotgroupedunderPisces? Q7.WhatarethecriteriaforclassificationoforganismsbelongingtokingdomMonera&Protista. Q8.a)Whatarethedifferentmeansbywhichinfectiousdiseasesarespread? b)Definevectors.Givetwoexamplesofvector‐bornediseases.Explainthemethodof preventionsofmalaria. Q9.a)Whatarethemethodsofreducingsoilerosion? b)WhatisGreen‐houseeffect? Q10.Whatprecautionswillyoutaketojustify“Preventionsisbetterthancure”.