Atomic Structure1

MUKESHSHSHARMA[DPSJODHPR]

ATOMICMODELS

Q1.Thespacebetweenprotonandelectroninhydrogenatomis:

(A)Absolutelyempty(B)Fullofelectromagneticradiation(C)Fullofair(D)FullofEther

Q2.Nucleonsareequalto:

(A)Numberofelectronsinanatom(B)Numberofprotonsinthenucleus(C)Numberofneutronsinthenucelus(D)Numberofprotonsandneutronsinthenucleus

Q3.Watermelonmodelofatomwasproposedby:

(A)Rutherford(B)Thomson(C)Bohr(D)Sommerfeld

Q4.Accordingtoclassicaltheory,theproposedcircularpathofanelectroninRutherfordatomicmodel

willbe:(A)Circular(B)Straightline(C)Parabolic(D)Spiral

Q5.Alphaparticlethatcomeclosertonuclei:

(A)Aredeflectedmore(B)Aredeflectedless(C)Makemorecollisions(D)None

Q6.Positivechargeinanatomis:

(A)scatteredallovertheatom(B)Concentratedinthenucleus(C)Revolvingaroundthenucleus(D)Noneistrue

Q7.Whichparticlemayberemovedfromastableneutralatomwithleastenergychange:(A)Anaparticle(B)Aneutron(C)Aproton(D)Anelectron

Q8.Ifeachhydrogenatomisexcitedbygiving8.4eVofenergythenthenumberofspectrallines

emittedisequalto:(A)None(B)Two(C)Three(D)Four

Q9.Rutherfordcreatedatheoreticalpictureoftheatombasedon:

(A)Starsingalaxy(B)Modelofplanetsrevolvingroundthesun(C)Behaviorofwavesintheocean(D)Cloudsinskythatmoveandmixinchangingshapes

Q10.Anatomisdefinedas:

(A)Largestparticleofmatter(B)Nondivisibleparticle(C)Thesmallestparticleofelement(D)None

Q11.Manyelementshavenonintegralatomicmassesbecause:

(A)Theyhaveisotopes(B)Theirisotopeshavenonintegralmasses(C)Theirisotopeshavedifferentmasses(D)Theconstituentsneutrons,protonsandelectronscombinetogivefractionalmasses


Q12.Accordingtodaltonsatomictheory,thesmallestparticleinwhichmattercanexist,

iscalled

(A)anatom(B)anion(C)anelectron(D)amolecule

Q13.Accordingtodaltonsatomictheory,anatom

(A)cannotbesubdivided(B)canbefurthersubdivided(C)containsneutrons,protonsandelectron(D)noneofthese

Q14.Accordingtodaltonsatomictheory,atomsofanelementare

(A)similarinallrespectsexcepttheirmasses(B)similarinallrespectsexcepttheirsizes(C)identical(D)different

Q15.Whichofthefollowingisthecorrectstatementforanelectron

(A)electronisaparticlehavinganegativechargeofoneunitandzeroatomicmass(B)electronisaparticlehavingapositivechargeofunitandzeroatomicmass(C)electronisaparticlehavinganegativechargeofoneunitandamassofabout91028g(D)electronisaparticlehavinganegativechargeandamassofabout7.11024gQ16.Rutherfordsexperimentonscatteringofparticlesshowedforthetimethattheatom

has(A)electrons(B)protons(C)nucleus(D)neutrons

Q17.Rutherfordsscatteringexperimentisrelatedtothesizeofthe

(A)nucleus(B)atom(C)electron(D)neutron

Q18.TheelementusedbyRutherfordinhisfamousscatteringexperimentwas

(A)tin(B)gold(C)lead(D)silver

Q19.Theprotonandneutronarecollectivelycalledas

(A)deuteron(B)positron(C)meson(D)nucleon

Q20.Theatomicweightofanelementis39.Thenumberofneutronsinitsnucleusisonemorethanthenumberofprotons.Thenumberofprotons,neutronsandelectronsrespectivelyinitsatomwouldbe(A)19,20,19(B)19,19,20(C)20,19,19(D)20,19,20

Q21.Rutherfordsexperiment,whichestablishedthenuclearmodeloftheatom,usedabeamof

(A)particles,whichimpingedonametalfoilandgotabsorbed(B)rays,whichimpingedonametalfoilandejectedelectrons(C)heliumatoms,whichimpingedonametalfoilandgotscattered(D)heliumnucleus,whichimpingedonametalfoilandgotscattered

Q22.Atomicnumbermeans

(A)numberofprotons(B)numberofelectrons(C)numberofneutrons(D)numberofnucleons

Q23.Thenumberofelectronsinonemoleculeofurea(

NH2

CONH2)is


(A)20(B)22(C)28(D)32

Q24.Theunitofatomicweightis

(A)gram(B)kg(C)grampermole(D)cm3Q25.Atomicweightofanelementisx.Theactualmassofoneatomofthatelementis

(A)xgram(B)xamu(C)x.60231023amu(D).6023x

1023amuQ26.Themassofonehydrogenatomisoftheorderof

(A)1023kg(B)1024kg(C)1028Kg(D)1027kgQ27.Thenumberofelectronsin2.1gramionofClis

(A)2.1(B)1.218(C)1.218.60231023(D)1.218.60231023Q28.Ifthemasstableofatomicweightswereestablishedwithoxygenatomassignedavalueof100,the

atomicweightofcarbonwouldbe(A)24(B)50(C)75(D)112

Q29.Ifthemassattributedtoaneutronwerehalvedandthatattributedtotheelectronweredoubled,the

atomicmassof6C12

would(A)remainapproximatelythesame(B)beapproximatelydoubled(C)beapproximatelyhalved(D)bereducedapproximatelyby25%

Q30.Whenalphaparticlearesentthroughathinmetalfoil,mostofthemgostraightthroughthefoil

because(A)aparticlesaremuchheavierthanelectrons(B)aparticlesarepositivelycharged(C)mostpartoftheatomisemptyspace(D)aparticlemovewithhighvelocity

Q31.Manyatomshavenonintegralatomicmassesbecause

(A)theyhaveisotopes(B)theirisotopeshavenonintegralmasses(C)theirisotopeshavedifferentmasses(D)theconstituentneutrons,protonsandelectronscombinetogivefractionalmasses

Q32.IntheneutralstatetheelementMconsistsoftheisotopes14M28

,14

M29

and14M30

intheratio60:30:20respectively.CorrectstatementsaboutMinthenaturalstateincludethat(A)the

atomicweightisbetween28.0and28.5(B)atomsofMcondition24electroneach(C)atomsofMmaycontain14,15or16neutronseach(D)atomsofMcontain16protonseach

Q33. The nucleus and an atom can be assumed to be spherical .The radius of the nucleus of mass no. A is given by .1 25 10 13 A 3/1 cm. The atomic radius of atom is 1 . If the mass no . is 64, the fraction of the atomic volume that is occupied by nucleusis:


(A)0.1

103(D).1251013Q34A:Atomiselectricallyneutral

R:Aneutralparticle,neutronispresentinthenucleusofatom.(A)Ifbothassertionandreasonaretrueandreasonisthecorrectexplanationofassertion(B)Ifbothassertionandreasonaretruebutreasonisnotthecorrectexplanationofassertion(C)Ifassertionistruebutreasonisfalse(D)Ifbothassertionandreasonarefalse(E)Ifassertionisfalsebutreasonistrue

Q35.A:Thomsonsatomicmodelisknownasraisinpuddingmodel.

R:Theaotmisvisualizedasapuddingofpositivechargewithelectrons(raisins)embeddedinit.

(A)Ifbothassertionandreasonaretrueandreasonisthecorrectexplanationofassertion(B)Ifbothassertionandreasonaretruebutreasonisnotthecorrectexplanationofassertion(C)Ifassertionistruebutreasonisfalse(D)Ifbothassertionandreasonarefalse(E)Ifassertionisfalsebutreasonistrue

QUANTISATION

Q36.Whatisthevalueofazimuthalquantumnumberforgsubshell?

Q37.Radiusofthenucleusisequalto1012cm.andthatoftheatomisequalto108cm.Whatisthe

fractionofthevolumeoftheatomoccupiedbynucleus?(A)1012(B)1012(C)1020(D)104

Q38.Thecorechargeonoxygenisequalto

(A)+2(B)2(C)6(D)+6

Q39.Thedualnatureofphotonsisdecribedby:

(A)Interference(B)E=mc2(C)Diffraction(D)E=hv

Q40.Light,awellknownfromofenergy,istreatedasafromofmatter,bysayingthatitconsistsof:

(A)Photonswhicharebundlesofenergy(B)Electronsorawavelikematter(C)Neutrons,sinceelectricallyneutral(D)None

Q41.Whichisnotthepropertyofthephotons:

(A)Momentum(B)Energy(C)Velocity(D)Restmass

Q42.Aquantawillhavemoreenergyif:

(A)Thewavelengthislarger(B)Thefrequencyishigher(C)Theamplitudeishigher(D)Thevelocityislower

Q43.Theenergyofelectromagneticradiationdependson:

(A)Amplitudeandwavelength(B)Wavelength(C)Amplitude(D)Temperatureofmediumthroughwhichitpasses

Q44.Quantumtheorywaspostulatedby:


(B)5100.5

(C)2105.2

(A)Rutherford(B)Maxwell(C)MaxPlanck(D)Becquerel

Q45.Themaximumwavelengthofradiationthatcanioniseasodiumatomis24140A

.Theionisationenergyofsodiumpermoleshallbe(A)2414.Jmo11(B)4977.Jmo11(C)2414.kJmo11(D)4977.kJmo11Q46.A:Electromagneticradiationsaround1015Hzarecalledasvisiblelight.R:Thisistheonlypartofelectromagenticradiationwhichisvisibletoeyes.(A)Ifbothassertionandreasonaretrueandreasonisthecorrectexplanationofassertion(B)Ifbothassertionandreasonaretruebutreasonisnotthecorrectexplanationofassertion(C)Ifassertionistruebutreasonisfalse(D)Ifbothassertionandreasonarefalse(E)Ifassertionisfalsebutreasonistrue

Q47.A:VIBGYORsignifiesthesevencolourofvisiblelight.

R:Redcolourcorrespondstohigherfrequencyandbluecolourtolowerfrequencyregion.(A)Ifbothassertionandreasonaretrueandreasonisthecorrectexplanationofassertion(B)Ifbothassertionandreasonaretruebutreasonisnotthecorrectexplanationofassertion(C)Ifassertionistruebutreasonisfalse(D)Ifbothassertionandreasonarefalse(E)IfassertionisfalsebutreasonistrueQ48.A:TheenergyofquantumofradiationisgivenbyE=h.

R:Quantumintheenergyequationsignifiestheprincipalquantumnumber.(A)Ifbothassertionandreasonaretrueandreasonisthecorrectexplanationofassertion(B)Ifbothassertionandreasonaretruebutreasonisnotthecorrectexplanationofassertion(C)Ifassertionistruebutreasonisfalse(D)Ifbothassertionandreasonarefalse(E)Ifassertionisfalsebutreasonistrue

Q49.A:Energyofradiationislargeifitswavelengthislarge.

R:Energy=h(=frequency,=c/)(A)Ifbothassertionandreasonaretrueandreasonisthecorrectexplanationofassertion(B)Ifbothassertionandreasonaretruebutreasonisnotthecorrectexplanationofassertion(C)Ifassertionistruebutreasonisfalse(D)Ifbothassertionandreasonarefalse(E)Ifassertionisfalsebutreasonistrue

BOHR

Q50.IftheionizationpotentialofLi+2is122.4eV.Whatisthe5thI.P.ofcarbon.

Q51.WhatisthewavelengthoflightrequiredtoraiseanelectronintheO7+ionfromn=1toshellton=2

shell.Q52.WhatistheradiusofBohrsfifthorbitforB+4.

Q53.Ifthepotentialenergyoftheelectronis10eVwhatistotalenergy?


Q54.Firstandsecondexcitationpotentialsofhydrogenatom(ineV)wouldbe

respectively

(A)10.2,12.1(B)12.1,10.2(C)13.6,3.4(D)3.4,13.6

Q55.Theseparationenergyoftheelectronpresentintheshelln=3is1.51eV.Whatistheenergyinthe

firstexictedstate?(A)1.51eV(B)3.4eV(C)+1.51(D)+3.eV

Q56.Theenergyrequiredfortheionizationofexcitedhydrogenatomwouldbe(ineV)

(A)13.6(B)>13.6(C)

(C)

40

(D)

0

Q63.WhenanelectronmovesfromLshelltoMshell,thenitwillbeaccompaniedby:

(A)Energyabsorption(B)Energyemission(C)gammarayemission(D)gammarayabsorption

Q64.Whentheelectronpassesfromenergystatenearesttothenucleustothirdenergylevel,itwill:

(A)Emitonequantumofenergy(B)Absorbonequantumofenergy(C)Emittwoquantumofenergy(D)Absorbtwoquantumofenergy


Q65.Evaluatethefollowingratiosfortheenergyoftheelectroninaparticularorbit:

[Kinetic:Potential]and[Total:Kinetic](A)[1:2]and[1:1](B)[1:2]and[1:1](C)[1:1]and[1:2](D)[1:2]and[1:2]

Q66.IftheI.E.ofHe+us54.4eVthen

(A)I.E.ofHis13.6eVandthatofLi+2122.4eV(B)I.E.ofHis13.6eVandthatofLi+2cannotbedetermined(C)I.E.ofHis13.6eVandthatofLi+2is27.2eV(D)Alloftheabovearewrong

Q67.Whichparticlecannotbeaccelerated

(A)particle(B)Electron(C)Neutron(D)Proton

Q68.SupposingtheelectronoftheHatomispresentintheLshell.Ifitliberates10.2eV,whatisthe

energyofthesystem?(A)3.4eV(B)13.6eV(C)10.2eV(D)0eV

Q69.ForHatom,theenergyrequiredfortheremovalofelectronfromvarioussubshellsisgivenas

under:

Theorderoftheenergieswouldbe:(A)E1

>E2

>E3

(B)E3

>E2

>E1

(C)E1

=E2

=E3

(D)Noneofthese

Q70.GoingfromKshelltoNshellincaseofHatom:

(A)K.E.decreases(B)Totalenergydecreases(C)Potentialenergydecreases(D)NoneoftheaboveQ71.Whatistheradiusratiofor2ndorbitofLi+2ion3rdorbitof

Be+3ion?

(A)3:1(B)16:27(C)4:9(D)3:4

Q72.Theratiooftheenergyoftheelectronsingroundstateofhydrogentotheelectronsinfirstexcited

stateofBe

+3is:(A)1:4(B)1:8(C)1:16(D)16:1.

Q73.Normally,thetimetakeninthetransitionis:

(A)Zero(B)1(C)105sec(D)108secQ74.Thetotalenergyofanatomicelectronis:

(A)Zero(B)Lessthanzero(C)Morethanzero(D)Sometimesmoreandsometimeslessthanzero


Q75.TheexpressionZegives:

(A)Thechargeofparticle(B)Thechargeonanatom(C)ThechargeonthenucleusofatomicnumberZ(D)Thekineticenergyofanparticle

Q76.TheenergyoftheelectronatinfinitedistancefromthenucleusinBohrsmodelistakenas:(A)Zero(B)Positive(C)Negative(D)Anyvalue

Q77.Asanelectronisbroughtfromaninfinitedistanceclosetothenucleusoftheatom,theenergyof

theelectronnucleussystem:(A)Increasestoagreaterpositivevalue(B)Decreasestoasmallerpositivevalue(C)Decreasestoasmallernegativevalue(D)Increasestoasmallernegativevalue

Q78.TheenergyofanelectroninthefirstBohrsorbitofHatomis13.6eV.Thepossibleenergyvalue

(s)oftheexcitedstate(s)forelectroninBohrsorbitsofhydrogenis(are):(A)3.4eV(B)4.2eV(C)6.8eV(D)+6.8eV

Q79.Whichelectrontransitioninahydrogenatomrequiresthelargestamountofenergy:

(A)From1=nto2=n(B)From2=nto3=n(C)From=nto1=n(D)From3=nto5=n

Q80.Bohrsmodelofatomexplains:

(A)Zeemaneffect(B)Heisenbergsprinciple(C)Strakeffect(D)Noneofthese

Q81.Bohrsatomictheorygavetheideaof:

(A)Quantumnumbers(B)Shapeofsublevels(C)Nucleus(D)Stationarystates

Q82.Theionzationpotentialofhydrogenatomis13.6eV.Theenergyrequiredtoremoveanelectron

fromthen=2stateofhydrogenatomis:(A)27.2eV(B)13.6eV(C)6.8eV(D)3.4eV

Q83.Thetotalenergyoftheelectroninthehydrogenatominthegroundstateis13.6eV.Whatisthe

stoppingpotential:(A)13.6volts(B)Zero(C)13.6volts(D)6.8volts

Q84.InanatomtwoelectronsmovearoundthenucleusincircularorbitsofradiiR&4R.Theratioof

thetimetakenbythemtocompleteonerevolutionis:(A)1:4(B)4:1(C)1:8(D)8:7

Q85.IonisationofHatomwouldproduce

(A)hydrideion(B)hydroniumion(C)proton(D)hydroxylion

Q86.Theradiusofanatomisoftheorderof

(A)cm1010(B)cm1210(C)cm1510(D)cm810


Q87.Theradiumofanatomisabout

(A)thesameasthevolumeofitsnucleus(B)fourtimestheradiusofitsnucleus(C)10,000timestheradiusitsnucleus(D)10

12timestheradiusofitsnucleus

Q88.(i)CalculatetheradiusoffirstBohrorbitofhydrogenatom(ii)Calculatethevelocityofanelectroninthegroundstateofhydrogenatom.(iii)Whatfractionofthevelocityoflightisthevelocityofanthegroundstateofhydrogenatom?(iv)HowlongdoesanelectrontakestocompleteonerevolutionaroundthenucleusinfirstBohrorbit

ofhydrogenatom?(v)HowmanytimesinoneseconddoesanelectrontravelaroundthenucleusinfirstBohrorbitof

hydrogen?Q89.Bohrsmodelcannotexplaintheemissionspectrumof

(A)H(B)He+(C)Li2+(D)Na

Q90.Angularmomentumofanelectroninthethnorbitofhydrogenatomisgivenby

(A)

2nh

(B)

2

nh(C)

2nh

(D)nh

Q91.Themaximumenergyispossessedbyanelectrons,whenitispresent

(A)innucleus(B)ingroundenergystate(C)infirstexcitedstate(D)atinfinitedistancefromthenucleus

Q92.Aswemoveawayfromthenucleus,theenergyoftheelectron

(A)decreases(B)remainsthesame(C)increases(D)firstdecreasesthenincreases

Q93.Whichofthefollowingelectronictransitionsinahydrogenatomwillrequirethelargestamountof

energy(A)fromn=1ton=2(B)fromn=2ton=3(C)fromn=ton=1(D)fromn=3ton=5

Q94.InBohrsmodelofatomwhenanelectronjumpsfromn=1ton=3,howmuchenergywillbe

absorbed(A).2151010ergs(B)0.1911x1010ergs(C)2.389x1010ergs(D)0.239x1010ergs

Q95.Ifenergyoftheelectroninhydrogenatominsomeexcitedstateis3.4eV,thenwhatwillbeits

angularmomentum(A)8.11030kgm2s1(B)1.21034kgm2s1(C)2.91037kgm2s1(D)2.11032kgm2s1Q96.Potentialenergyofanelectronintheatomis

(A)

Ze2/r(B)

Ze2/r(C)Ze

2/r2(D)

Ze2/r2


Atomic Structure1

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