WPC}1 fmb}|Ք#nة >U3`|W5reAh*ť 5?NxϹ›]k](%)AlM!, BBcıYBhD,\ *ӕ!e@s2u]YM:4g%З փ`rW8NU>D 0 0C 0( 0" 0 0 0 0 0 0 0 0i 0N 00 0 0 0 0 0 0o 0S 07 0 0 0 0 0 0Xk!U:" 0 :" 0<7$ 0/s$ 0% 0F' 03( 1W* 7 t*UP,* 1[* 7 + 1U+ 7 h+ 1at+ 7+ 1c+ 7F, 1gT, 7,f,a, B`*,f -a -f-a!-f5-a7-fK-aM- Ba-~- 0-#V.UN0 %e0Mk0(o0N0 1u0 721^ @1wL14P1d1 mf1\  `&Times New Roman' CHAPTER 4 susie0Giordano .   2P+M 0_level1  , 8.4 <DL!823  ..  5+ 4 <DL!5  2M+M 0_level2  X 5+4 44 <DL!523  ..  5+ 4 <DL!5  2M+M 0_level3   5+` ` ` <DL!523  ..  5+ 4 <DL!5  2J+M 0_level4   2( <DL!223  ..  5+ 4 <DL!5  2J+M 0_level5   2( <DL!223  ..  5+ 4 <DL!5  2G+M 0_level6   /% <DL!/23  ..  5+ 4 <DL!5  2G+M 0_level7  4 /% <DL!/23  ..  5+ 4 <DL!5  2D+M 0_level8  ` ,"< <<DL!,23  ..  5+ 4 <DL!5  2D+M 0_level9   ,"h hhDL!,23  ..  5+ 4 <DL!5  2PM 0_levsl1  , 8.4 <DL!823  Ԁ  5+ 4 <DL!5  2MM 0_levsl2  X 5+4 44 <DL!523  Ԁ  5+ 4 <DL!5  2MM 0_levsl3   5+` ` ` <DL!523  Ԁ  5+ 4 <DL!5  2JM 0_levsl4   2( <DL!223  Ԁ  5+ 4 <DL!5  2JM 0_levsl5   2( <DL!223  Ԁ  5+ 4 <DL!5  2GM 0_levsl6   /% <DL!/23  Ԁ  5+ 4 <DL!5  2GM 0_levsl7  4 /% <DL!/23  Ԁ  5+ 4 <DL!5  2DM 0_levsl8  ` ,"< <<DL!,23  Ԁ  5+ 4 <DL!5  2DM 0_levsl9   ,"h hhDL!,23  Ԁ  5+ 4 <DL!5  2PM 0_levnl1  , 8.4 <DL!823   5+ 4 <DL!5  2MM 0_levnl2  X 5+4 44 <DL!523   5+ 4 <DL!5  2MM 0_levnl3   5+` ` ` <DL!523   5+ 4 <DL!5  2JM 0_levnl4   2( <DL!223   5+ 4 <DL!5  2JM 0_levnl5   2( <DL!223   5+ 4 <DL!5  2GM 0_levnl6   /% <DL!/23   5+ 4 <DL!5  2GM 0_levnl7  4 /% <DL!/23   5+ 4 <DL!5  2DM 0_levnl8  ` ,"< <<DL!,23   5+ 4 <DL!5  2DM 0_levnl9   ,"h hhDL!,23   5+ 4 <DL!5  6 4Heading 1 CE O* `"Comic Sans MSO       XXXS\  `&Times New RomanS  CE * `"Comic Sans MS6 w4Heading 2O* `"Comic Sans MSO      XXXS\  `&Times New RomanS<:Default Para6|} 4Body Text   O* `"Comic Sans MSO     XXXS\  `&Times New RomanS < :Body Text I1 * O* `"Comic Sans MSO 4 /% <DL!/  5+ 4 <DL!5XXXS\  `&Times New RomanS * < :Body Text In  O* `"Comic Sans MSO 4 /% <DL!/  5+ 4 <DL!5XXXS\  `&Times New RomanS  :|} 8Body Text 2O* `"Comic Sans MSO     XXXS\  `&Times New RomanS  359?CGKOS1 1. o o& (\ Y`Symbol 359?GKOSW2 1.(1) o o)  359=AEIMQ3 o o o+  35;?GKOU[41. (a)- i.1.a.- i. 35;?EKQW]51. i.1.a.i.1.a./ i. 35;CIOU[a61.(a)i.1.a.i.1.a.1 i.Table_A& d dTable_BTable_CTable_DTable_E d#|x(G$..      CEUS.,BXkwXXBXXkwXXBXkwLexmark 3200 Series ColorFinePX,,,,PX0(9 Z6Times New Roman RegularBX3#37=CIQYag1.a.i.(1)(a)(i)1)a)Gi)SN- TI-esNOTESǩU @G!..      CEUS.,BXkwXXBXXkwXXBXkw  _       W" XXkw       "   CHAPTER4.6:THESTRUCTUREANDPROPERTIES W OFSOLIDS" v݌ s Ќ  X5X XkwXXX5   FiXXkw.Fi & (03G""  ,B.4 <DL!XB  X,E(4 4 <DL!4X!E( .&2 3   4   . (Chemistshaveclassifiedsolidsubstancesonthebasisof p thetypesofbondsthatholdtheirmoleculesorions   together.&#݌ Q  Ќ X! X44X!!   ""  ,B.4 <DL!XB  X,E(4 4 <DL!4X!E( .2 3   4   . (Thisisnottheonlywaytoclassifysolids.݌  ?  Ќ X! X44X!!   ""  ,B.4 <DL!XB  X,E(4 4 <DL!4X!E( .2 3   4   . (Chemistsalsodividesolidsintotwocategoriesbasedonthe    macroscopicproperties thatarisefromthe arrangements     oftheircomponentparticles.݌ e  Ќ X! X44X!!   ""  X?+4 44 <DL!X?  X?% <DL!444X!?G 2  1  .3     Crystallinesolids haveorganizedparticle 4  arrangements,sotheyhavedistinctshapes(Eg. y" Gemstonessuchasamethystandgarnet).G  ݌ g Ќ ! X  X!!   ""  X?+4 44 <DL!X?  X?% <DL!444X!? 2  2  .3     Amorphoussolids haveindistinctshapes,because 6 theirparticlearrangementlacksorder(Eg.Glassand { rubber). y ݌  Ќ ! X  X!!   X5X..XX5CECE.,....      &  ,   .BondingandPropertiesofCrystallineSolids,  Ԍ ` Ќ  . .. CE.,CE.,  ' ) (00& / /""  ,B.4 <DL!XB  X,E(4 4 <DL!4X!E( .2 3   4   . (Chemistsfurtherclassifysolidsintofivedifferenttypes, o"  basedontheircomposition.(CopyTable1Classifying #]! Solids,page268)݌ $" Ќ X! X44X!!   ""  ,B.4 <DL!XB  X,E(4 4 <DL!4X!E( .'2 3   4   . (Thesetypesare:'$݌ >&# Ќ X! X44X!!   ""  X?+4 44 <DL!X?  X?% <DL!444X!?2  1  .3     AtomicSolids݌ (q& Ќ ! X  X!!   ""  X?+4 44 <DL!X?  X?% <DL!444X!?2  2  .3     Ionic݌  *' Ќ ! X  X!!   ""  X?+4 44 <DL!X?  X?% <DL!444X!?o2  3  .3     MetallicoD݌ R+(  Ќ ! X  X!!   ""  X?+4 44 <DL!X?  X?% <DL!444X!?2  4  .3     MolecularSolids݌ ,@*! Ќ ! X  X!!   ""  X?+4 44 <DL!X?  X?% <DL!444X!?2  5  .3     CovalentNetworkSolids݌ -+" Ќ ! X  X!!   ATOMICSOLIDS: W   + (00) / /""  ,B.4 <DL!XB  X,E(4 4 <DL!4X!E( .j2 3   4   . (Aremadeupofindividualatomsthatareheldtogether & solelybydispersionforces.jg ݌ k Ќ X! X44X!!   ""  ,B.4 <DL!XB  X,E(4 4 <DL!4X!E( .!2 3   4   . (Thenumberofactuallyoccurringatomicsolidsisquite Y small.!"݌   Ќ X! X44X!!   ""  ,B.4 <DL!XB  X,E(4 4 <DL!4X!E( .#2 3   4   . (Infact,thenoblegasesintheirsolidstatearetheonly :  examples.#$݌  (  Ќ X! X44X!!   ""  ,B.4 <DL!XB  X,E(4 4 <DL!4X!E( .&2 3   4   . (Sincetheonlyforcesholdingatomicsolidstogetherare  m  dispersionforces,thesesolidshaveverylowmeltingand    boilingpoints.&'݌ N  Ќ X! X44X!!   IONICCRYSTALS:  / / ""  ,B.4 <DL!XB  X,E(4 4 <DL!4X!E( .(2 3   4   . (An ioniccrystal isanarrayofions,arrangedatregular P positionsina crystallattice .()݌  Ќ X! X44X!!   ""  ,B.4 <DL!XB  X,E(4 4 <DL!4X!E( .7+2 3   4   . (Acrystallatticeismadeupofidenticalrepeating unitcells  1 thatgivethecrystalitscharacteristicshape.7+4,݌ v Ќ X! X44X!!   CHARACTERISTICSOFANIONICCOMPOUND: E  ) (00+ ""  ?+` ` ` <DL!X?   4?" <DL!` ` ` X!?\.2(  1  )3      Ioniccompoundsarehardbutbrittlesolidsat  x SATP.\.?/݌ " Ќ 4$ X<X!$   ""  ?+` ` ` <DL!X?   4?" <DL!` ` ` X!?[02(  2  )3      Conductelectricityintheliquidstate,butnot Y#! thesolidstate.[0>1݌ $G" Ќ 4$ X<X!$   ""  ?+` ` ` <DL!X?   4?" <DL!` ` ` X!?h22(  3  )3      Formingconductingsolutionsinwater.h2K3݌ %# Ќ 4$ X<X!$   ""  ?+` ` ` <DL!X?   4?" <DL!` ` ` X!?E42(  4  )3      Highmeltingpoints.E4(5݌ ('$ Ќ 4$ X<X!$   Recap: .o,# ЇIonicBonding: isdefinedtheoreticallyasthesimultaneous W attractionofan E ""  <( <DL!X<  X?%4 44<DL!  X!?( .62 3   4   . (Thefullchargeontheionsprovidesagreaterforceof & attractionthandothepartialchargesonpolarmolecules.67݌ k Ќ X' X444<X!'   ""  <( <DL!X<  X?%4 44<DL!  X!?( .92 3   4   . (Ingeneral,ionicbondingismuchstrongerthanall Y intermolecularforces(eg.ToothenamelCalciumPhosphate   ismuchharderthanice).99݌ :  Ќ X' X444<X!'   METALLICCRYSTALS: <,)!   -*+"  + (00) / /""  ,B.4 <DL!XB  X,E(4 4 <DL!4X!E( .<2 3   4   . (Abouttwothirdsofallnaturallyoccurringelementsare W  metals.<=݌ E Ќ X! X44X!!    ....     &   >  CHARACTERISTICSOFMETALS >V? 2?Ԍ k Ќ  ....  'kJ? - (00+ / /""  ,B.4 <DL!XB  X,E(4 4 <DL!4X!E@2  1  .3   4   Conductheatandelectricityinboththeirsolidstateand :  liquidstates.@A݌  (  Ќ X! X44X!!   ""  ,B.4 <DL!XB  X,E(4 4 <DL!4X!EB2  2  .3   4   Mostaremalleableandductile:easilystretched,bentand  m  deformedwithoutshattering.BC݌    Ќ X! X44X!!   ""  ,B.4 <DL!XB  X,E(4 4 <DL!4X!EE2  3  .3   4   Metalstendtochangestateatmoderatehigh N  temperatures.EE݌ <  Ќ X! X44X!!   ""  ,B.4 <DL!XB  X,E(4 4 <DL!4X!EG2  4  .3   4   Mostmetalshaveoneortwovalenceelectrons.GG݌   Ќ X! X44X!!   ""  ,B.4 <DL!XB  X,E(4 4 <DL!4X!EH2  5  .3   4   Shiny,silvery.HI݌  Ќ X! X44X!!   ""  ,B.4 <DL!XB  X,E(4 4 <DL!4X!EJ2  6  .3   4   Solidatroomtemperature,exceptformercury,whichis b  liquid.JK݌ P Ќ X! X44X!!   ""  ,B.4 <DL!XB  X,E(4 4 <DL!4X!EL2  7  .3   4   Allmetalshaveacontinuousandverycompactcrystalline  structure.LM݌ 1 Ќ X! X44X!!   ""  X?+4 44 <DL!X?  ( .N2 3   4   . (Basedonelectronegativitydifferences,metalsdonotform  ionicbondswiththemselvesorwithothermetals.NZO݌ E Ќ X$ X444X!$   ""  X?+4 44 <DL!X?  ( .P2 3   4   . (Metalsdonothaveasufficientnumberofvalenceelectrons 3 toformcovalentbondswithoneanother.P`Q݌  x Ќ X$ X444X!$   ""  X?+4 44 <DL!X?  ( .R2 3   4   . (Metalsdoshareelectrons.R^S݌ " Ќ X$ X444X!$   ""  X?+4 44 <DL!X?  ( .WT2 3   4   . (Unliketheelectronsharingincovalentcompounds,however, Y#! electronsharinginmetalsoccursthroughouttheentire $G" structureofthemetal.WTT݌ %# Ќ X$ X444X!$   ""  X?+4 44 <DL!X?  ( .V2 3   4   . (The electronseamodel picturesmetalsasbeingcomposed ('$ ofadenselypackedcoreofmetalliccations,withina m(& delocalizedregionofshared,mobilevalenceelectrons.V7W݌ )[' Ќ X$ X444X!$   ""  X?+4 44 <DL!X?  ( .X2 3   4   . (Theforceofattractionbetweenthepositivelycharged *(  cationsandthepoolofvalenceelectronsthatmovesthem <,)! constitutea metallicbond. Observefigure4,page269.XY݌ -*+" Ќ X$ X444X!$    .o,# Ї PropertiesExplainedbytheElectronSeaModel: W  ""  ?+` ` ` <DL!X?   ?" <DL!` ` ` X!?[2(  a  )3      Conductivity:metalsaregoodconductorsof  electricityandheatbecauseelectronscan & movefreelythroughoutthemetallic k structure.Thisfreedomofmovementisnot Y possibleinsolidioniccompounds,becausethe   valenceelectronsareheldwithinthe :  individualionicbondsinthelattice.[\݌  (  Ќ $ X<X!$   ""  ?+` ` ` <DL!X?   ?" <DL!` ` ` X!?_2(  b  )3      MalleabilityandDuctility:themalleabilityof  m  metalscanbeexplainedbyviewingmetallic    bondsasbeingnondirectional.Thepositive N  ionsareoftenlayeredasfixedarrays. <  Whenstressisappliedtoametal,onelayer   ofpositiveionscanslideoveranotherlayer.  Thelayersmovewithoutbreakingthearray, b  whichisthereasonwhymetalsdonot P shatterimmediatelyalongaclearlydefined  pointofstress.Thedelocalizedelectrons 1 continuetoexertauniformattractiononthe v positiveions.__݌ d Ќ $ X<X!$   ""  ?+` ` ` <DL!X?   ?" <DL!` ` ` X!?c2(  c  )3      MeltingandBoilingPoints:themeltingand  boilingpointsofGroup1(1A)metalsare E generallylowerthanthemeltingandboiling 3 pointsofGroup2(IIA)metals.c|d݌  x Ќ $ X<X!$   9% <DL!X9 rE(N N N <DL!<X!EӀ Reason:  m(& ""  rE( <DL!N N N X!E  ` 9< <DL!  X!9Fi.f2-3   <   .Fithegreaternumberofvalenceelectrons )[' andlargerpositivechargeresultin *(  strongermetallicbondingforces.fg݌ <,)! Ќ r` *N N N X!<<X!*   ""  rE( <DL!N N N X!E  ` 9< <DL!  X!9Fi.ei2-3   <   .FiԀGroup2metalsaresmallerinsizethan -*+" Group1.eiYj݌ .o,# Ќ r` *N N N X!<<X!*   4rB% <DL!N N N X!B""  4E( <DL!<X!E  X?"4 44DL!  X!?( .k2 3   4   . (Trendsinvolvingthetransitionmetalsaremorecomplex E becausetheyhaveagreaternumberofunpairedelectrons  intheirdorbitals.kl݌ & Ќ 4X0<X!444X!0   ""  4E( <DL!<X!E  X?"4 44DL!  X!?( .cn2 3   4   . (ObserveTable2:ExplainingthePropertiesofMetals,page k 269.cn]o݌ Y Ќ 4X0<X!444X!0   4H+ 4 <DL!<X!H Alloys:  (   + (00- / / ""  ,E.4 <DL!X!E  X,E(4 4 <DL!4X!E( .q2 3   4   . (Thephysicalpropertiesofpuremetalscanbealtered    significantlybycombiningthemwithothermetals.qr݌ N  Ќ X$ X!44X!$    / (00+ / /""  ,E.4 <DL!X!E   R,B%. . <DL!4X!Bt2  1  .3   .   Ifatomsoftheaddedmetalaresimilarinsizeto   thoseoftheoriginalpuremetal,thesearecalled   substitutionalalloys. tu݌ b  Ќ R' X!. . X!'   ̀  E ""  ,E.4 <DL!X!E   R,B%. . <DL!4X!Bmw2  2  .3   .   Ifatomsofthealloyingsubstancearesosmallthat 3 theywillfitintothespacesbetweenatomsofthe  x puremetalcrystalthesealloysarecalled interstitual " alloys (ex.steel!producedbyaddingcarbontoiron).mwYx݌ Y#! Ќ R' X!. . X!'   Bothtypesofalloysareusuallyharderandstrongerbecauseof2 %# factors: ('$  1 (00/ / /""  ,E.4 <DL!X!E  } ,E(  <DL!4X!Ev{2  1  .3      Addedmetalmayprovideadditionalvalenceelectrons. )[' ThisiswhathappenswhensmallamountsofCuandMnare *(   addedtoAltoproduce duralumin.v{e|݌ <,)! Ќ ' X! X!' }  ""  ,E.4 <DL!X!E  } ,E(  <DL!4X!E~2  2  .3      Theatomsofthealloyingmetal,becausetheyarea W differentsize,mayinterferewiththeslippingoflayersof E atomswithinthemetal.~~݌   ' X! X!' }  ^E.:::4 <DL!X!E# *.... 4^B% <DL!:::4X!B  #݀  Example:(a)brass:analloyofCuandZnisconsiderably Y harderthanpureCu.#݀݌   Ќ ^40:::4X!<X!0.... *   - (001 ""  ^E( <DL!:::4X!E  ` 9< <DL!  X!9Fi.`2-3   <   .Fithedegreeofhardnessincreaseswiththe :  amountofZnadded.`T݌  (  Ќ ^` *:::4X!<<X!*   ^H+ 4 <DL!:::4X!H$ .... 4<% <DL!X!<  $߅  ݀(b)Steel:dissolvedCinFemakesitdifficultfor N  layersofFeatomstomovesmoothlyoverone <  another.$߅݌   Ќ 4* X!<X!*....   MOLECULARSOLIDS: m(&   + (00- ""  ,E.4 <DL!X!E  X,E(4 4 <DL!4X!E( .ֈ2 3   4   . (Astheirnameimplies,aremadeupofmolecules.ֈ։݌ *(  Ќ X$ X!44X!$   ""  ,E.4 <DL!X!E  X,E(4 4 <DL!4X!E( .2 3   4   . (Likeatomicsolids,themoleculesthatmakeupmolecular <,)! solids,suchasfrozenmethane,areheldtogethermainlyby -*+" dispersionforces.݌ .o,# Ќ X$ X!44X!$   ""  ,E.4 <DL!X!E  X,E(4 4 <DL!4X!E( .u2 3   4   . (Theytendtohavelowmeltingandboilingpoints.uu݌ W Ќ X$ X!44X!$   ""  ,E.4 <DL!X!E  X,E(4 4 <DL!4X!E( .2 3   4   . (Inpolarmolecularsolids,however,strongerdipoledipole E forces,andsometimeshydrogenbonding,givethese  compoundshighermeltingpointsandboilingpointsthannon & polarmolecularsolids.݌ k Ќ X$ X!44X!$   COVALENTNETWORKCRYSTALS:  (   / /""  ,E.4 <DL!X!E  X,E(4 4 <DL!4X!E( .ʒ2 3   4   . (Unliketheintramolecularcovalentbondsthatholdatoms    togetherindiscretemolecules,itispossibleforatomsto N  bondcovalentlyintocontinuoustwoorthreedimensional <  arrays.ʒʓ݌   Ќ X$ X!44X!$   ""  ,E.4 <DL!X!E  X,E(4 4 <DL!4X!E( .2 3   4   . (ԀThesesubstancesareamongthehardestmaterialsknown.݌  Ќ X$ X!44X!$   ""  ,E.4 <DL!X!E  X,E(4 4 <DL!4X!E( .2 3   4   . (Theyareverybrittle,haveveryhighmeltingpoints,are b  insolubleandarenonconductorsofelectricity.݌ P Ќ X$ X!44X!$   ""  ,E.4 <DL!X!E  X,E(4 4 <DL!4X!E( .2 3   4   . (Thepropertiesofhardnessandhighmeltingpointprovide  theevidencethattheoverallbondinginthelarge 1 macromoleculeofacovalentnetworkisverystrong v strongerthanmostionicbondingandintermolecular d bonding.݌  Ќ X$ X!44X!$   ""  ,E.4 <DL!X!E  X,E(4 4 <DL!4X!E( .2 3   4   . (Acarboncarbonbondindiamondconsistsofaninterlocking E structureofcovalentlybondedcarbons,whichprovidethe 3 strengthofthematerial.݌  x Ќ X$ X!44X!$   ""  ,E.4 <DL!X!E  X,E(4 4 <DL!4X!E( .2 3   4   . (Individualatomsarenoteasilydisplacedandtherefore " makingthesampleveryhard.݌ Y#! Ќ X$ X!44X!$   ""  ,E.4 <DL!X!E  X,E(4 4 <DL!4X!E( .2 3   4   . (Inordertomeltacovalentnetworkcrystal,manycovalent $G" bondsneedtobebroken,whichrequiresconsiderable %# amountofenergy,sothemeltingpointsareveryhigh.݌ ('$ Ќ X$ X!44X!$   ""  ,E.4 <DL!X!E  X,E(4 4 <DL!4X!E( .2 3   4   . (Electronsincovalentnetworkcrystalsareheldeitherwithin m(& theatomsorinthecovalentbonds.݌ )[' Ќ X$ X!44X!$   ""  ,E.4 <DL!X!E  X,E(4 4 <DL!4X!E( .2 3   4   . (Ineithercase,theyarenotfreetomovethroughthe *(  network.݌ <,)! Ќ X$ X!44X!$   " "  ,E.4 <DL!X!E  X,E(4 4 <DL!4X!E( .)2 3   4   . (Thisexplainswhythesesubstancesarenonconductorsof -*+" electricity.))݌ .o,# Ќ X$ X!44X!$   " "  ,E.4 <DL!X!E  X,E(4 4 <DL!4X!E( .`2 3   4   . (Carbonisanextremelyversatileatomintermsofits W bondingandstructures.``݌ E Ќ X$ X!44X!$   " "  ,E.4 <DL!X!E  X,E(4 4 <DL!4X!E( .2 3   4   . (Carboncanbondtoitselftoformavarietyofpurecarbon  substances.݌ & Ќ X$ X!44X!$   " "  ,E.4 <DL!X!E  X,E(4 4 <DL!4X!E( .ۯ2 3   4   . (Itcanform3Dtetrahedralarrangements(diamond),layers k ofsheets(graphite),largesphericalmolecules(buckyballs) Y andlong,thintubes(carbonnanotubes).ۯ۰݌   Ќ X$ X!44X!$   " "  ,E.4 <DL!X!E  X,E(4 4 <DL!4X!E( .2 3   4   . (Theseare4 allotropicforms ofcarbon.݌ :  Ќ X$ X!44X!$    <% <DL!X!< ALLOTROPES: aredifferentcrystallineormolecularformsof    thesameelementthatdifferinphysicaland N  chemicalproperties. <       / /""  ,H.4 <DL!  X!H  X,E(4 4 <DL!4X!E( .2 3   4   . (Graphiteisasoft,twodimensionalnetworksolidthatisa b  goodconductorofelectricity.݌ P Ќ X'  X!44X!'   ""  ,H.4 <DL!  X!H  X,E(4 4 <DL!4X!E( .U2 3   4   . (Ithasahighmeltingpoint,whichsuggestsstrongbonds,  butitssoftnessindicatesthepresenceofweakbondsas 1 well.UX݌ v Ќ X'  X!44X!'   ""  ,H.4 <DL!  X!H  X,E(4 4 <DL!4X!E( .ں2 3   4   . (Eachcarbonformsthreestrongcovalentbondswiththree d ofitsnearestneighboursinatrigonalplanarpattern.ںݻ݌  Ќ X'  X!44X!'   ""  ,H.4 <DL!  X!H  X,E(4 4 <DL!4X!E( .C2 3   4   . (Thisstructuregivesstabilitytothelayers.CF݌ E Ќ X'  X!44X!'   ""  ,H.4 <DL!  X!H  X,E(4 4 <DL!4X!E( .U2 3   4   . (Thefourth,nonbondingpairofelectronsisdelocalizedand 3 freetomovewithinthelayers.UX݌  x Ќ X'  X!44X!'   ""  ,H.4 <DL!  X!H  X,E(4 4 <DL!4X!E( .2 3   4   . (Thisgivesgraphitetheabilitytoconductanelectric " current.݌ Y#! Ќ X'  X!44X!'   ""  ,H.4 <DL!  X!H  X,E(4 4 <DL!4X!E( .2 3   4   . (Therearenointramolecularforcesbetweenthelayers.݌ $G" Ќ X'  X!44X!'   ""  ,H.4 <DL!  X!H  X,E(4 4 <DL!4X!E( .2 3   4   . (Dispersionforcesattractonelayertoanother,enabling %# layerstoslidebyoneanother.݌ ('$ Ќ X'  X!44X!'   ""  ,H.4 <DL!  X!H  X,E(4 4 <DL!4X!E( .N2 3   4   . (Graphitefeelsslipperyasaresultofthischaracteristic.NQ݌ m(& Ќ X'  X!44X!'   " "  ,H.4 <DL!  X!H  X,E(4 4 <DL!4X!E( .n2 3   4   . (Infact,manyindustrialprocessesusegraphiteasa )[' lubricant.nq݌ *(  Ќ X'  X!44X!'   " "  ,H.4 <DL!  X!H  X,E(4 4 <DL!4X!E( .2 3   4   . (Indiamond,eachcarbonatomformsfourstrongcovalent <,)!  bondswithfourothercarbonatoms.݌ -*+" Ќ X'  X!44X!'   " "  ,H.4 <DL!  X!H  X,E(4 4 <DL!4X!E( .2 3   4   . (Thisthreedimensionalarraymakesdiamondthehardest W  naturallyoccurringsubstance.݌ E Ќ X'  X!44X!'   " "  ,H.4 <DL!  X!H  X,E(4 4 <DL!4X!E( .\2 3   4   . (Thevalenceelectronsareinhighlylocalizedbondsbetween  carbonatoms.\_݌ & Ќ X'  X!44X!'   " "  ,H.4 <DL!  X!H  X,E(4 4 <DL!4X!E( .2 3   4   . (Therefore,diamonddoenotconductelectricity.݌ k Ќ X'  X!44X!'   ""  ,H.4 <DL!  X!H  X,E(4 4 <DL!4X!E( .2 3   4   . (Theplanesofatomswithinthediamondreflectlight,which Y givesdiamonditsbrillianceandsparkle.݌   Ќ X'  X!44X!'   ""  ,H.4 <DL!  X!H  X,E(4 4 <DL!4X!E( .2 3   4   . (Theregulararrangementofthecarbonatomsina :  crystallinestructure,coupledwiththestrengthofthe  (  covalentCCbonds,givesdiamonditsextremehardness,and  m  makesitinerttocorrosivechemicals.݌    Ќ X'  X!44X!'   ""  ,H.4 <DL!  X!H  X,E(4 4 <DL!4X!E( .2 3   4   . ( Fullerenes makeupagroupofsphericalallotropesof N  carbon.݌ <  Ќ X'  X!44X!'   ""  ,H.4 <DL!  X!H  X,E(4 4 <DL!4X!E( .:2 3   4   . (Aspecialfullerenegiventhenamebuckminsterfullerene   resembledageodesicdomedstructuredesignedby  architectR.BuckminsterFuller.:=݌ b  Ќ X'  X!44X!'   ""  ,H.4 <DL!  X!H  X,E(4 4 <DL!4X!E( .2 3   4   . (Alsoknownas buckyballs,C60isjustoneofseveral P fullerenesthathavebeendiscovered.݌  Ќ X'  X!44X!'   ""  ,H.4 <DL!  X!H  X,E(4 4 <DL!4X!E( .02 3   4   . (Becauseoftheirsphericalshape,researchersbelievedthat 1 fullerenesmightmakegoodlubricants.03݌ v Ќ X'  X!44X!'   ""  ,H.4 <DL!  X!H  X,E(4 4 <DL!4X!E( .2 3   4   . (Recently,microscopiclevelresearchhasdevelopedvery d smallcarbonnetworkscalled nanotubes. ݌  Ќ X'  X!44X!'   ""  ,H.4 <DL!  X!H  X,E(4 4 <DL!4X!E( .2 3   4   . (Nanotubesarelikeafullerenenetworkthathasbeen E stretchedintoacylindershape.݌ 3 Ќ X'  X!44X!'   ""  ,H.4 <DL!  X!H  X,E(4 4 <DL!4X!E( .82 3   4   . (NanotubesofC400andhighermayhaveapplicationsinthe  x manufactureofhighstrengthfibres.8;݌ " Ќ X'  X!44X!'    E+ 4 <DL!  X!E AMORPHOUSSOLIDS: ('$  / /""  ,E.4 <DL!X!E  X,E(4 4 <DL!4X!E( .U2 3   4   . (Solidsthatarecomposedofmoleculesthatarenot )[' arrangedinanorderly,crystallinestructure.UU݌ *(  Ќ X$ X!44X!$   ""  ,E.4 <DL!X!E  X,E(4 4 <DL!4X!E( .2 3   4   . (Glassisatypicalexample.݌ <,)! Ќ X$ X!44X!$   ""  ,E.4 <DL!X!E  X,E(4 4 <DL!4X!E( .2 3   4   . (Sodalimeglassmakesupalmost90%ofallglass -*+" manufactured.݌ .o,# Ќ X$ X!44X!$   ""  ,E.4 <DL!X!E  X,E(4 4 <DL!4X!E( .2 3   4   . (Itisalsoreferredtoasanionicglass,withanapproximate W compositiongivenbytheformulaNa2OCaO(SiO2)6.݌ E Ќ X$ X!44X!$   ""  ,E.4 <DL!X!E  X,E(4 4 <DL!4X!E( .K2 3   4   . (Fouroxygenatomsinatetrahedronsurroundeachsilicon  atom.KK݌ & Ќ X$ X!44X!$   ""  ,E.4 <DL!X!E  X,E(4 4 <DL!4X!E( .|2 3   4   . (Thesetetraheraarerandomlyarrangedamonganetworkof k Na+andCa2+ionsthatfillinthespacestobalancethe Y negativechargeonthetetrahedronnetwork.||݌   Ќ X$ X!44X!$   WHATISSOSPECIALABOUTGLASS? <  ""  ,E.4 <DL!X!E  X,E(4 4 <DL!4X!E( .g2 3   4   . (Glassisan isotropicmaterial. gg݌ b  Ќ X$ X!44X!$   ""  ,E.4 <DL!X!E  X,E(4 4 <DL!4X!E( .k2 3   4   . (Thismeansthatitspropertiesarethesameinalldirections.kk݌ P Ќ X$ X!44X!$   ""  ,E.4 <DL!X!E  X,E(4 4 <DL!4X!E( .2 3   4   . (Thisausefulproperty,sinceitmeansthatglassexpands  uniformlywhenheated.݌ 1 Ќ X$ X!44X!$   " "  ,E.4 <DL!X!E  X,E(4 4 <DL!4X!E( .2 3   4   . (Changingtheproportionofthecomponentsoraddingother E componentscangivedifferentpropertiesgiventotheglass.݌ 3 Ќ X$ X!44X!$   " "  ,E.4 <DL!X!E  X,E(4 4 <DL!4X!E( .72 3   4   . (Forexample:addingB2O3sothatitmakesup13%byweight  x oftheglassresultsinborosilicateglass,soldasPyrex.77݌ " Ќ X$ X!44X!$   " "  ,E.4 <DL!X!E  X,E(4 4 <DL!4X!E( .2 3   4   . (Itslowcoefficientofthermalexpansionindicatesthatit Y#! willexpandverylittlewhenheated.݌ $G" Ќ X$ X!44X!$   " "  ,E.4 <DL!X!E  X,E(4 4 <DL!4X!E( .2 3   4   . (Pyrexis,therefore,an ovenproofproduct.݌ %# Ќ X$ X!44X!$   " "  ,E.4 <DL!X!E  X,E(4 4 <DL!4X!E( . 2 3   4   . (Flintglasscontainslead(II)oxide,PbOandisusedinlenses ('$ becauseofitslowrefractiveindex,meaningthatlight m(& passingthroughdoesnotbendverymuch.  ݌ )[' Ќ X$ X!44X!$    .o,# ""  ,E.4 <DL!X!E  X,E(4 4 <DL!4X!E .( ]  2 3   4    ( ]Someelementsexistinamorphousform.  ݌ W Ќ X$ X!44X!$   .  1 (00+ ""  XB+4 44 <DL!X!B   X?% <DL!444X!?2(  a  )3     Charcoalisanimpure,amorphousformofcarbon.y݌ T Ќ ' X!  X!'   ""  XB+4 44 <DL!X!B   X?% <DL!444X!?2(  b  )3     ݀Whensulphurisheatedtoitsboilingpointand B cooledquickly,anamorphousformcalled plastic  sulphur forms.IthastheformulaS( . . (,andisoften #  called polymericsulphur.f݌ h   Ќ ' X!  X!'   ""  XB+4 44 <DL!X!B   X?% <DL!444X!?x2(  c  )3     Metalalloyscanbeamorphous.Liquidmetalalloyis  V  anamorphousalloyofZirconiummixedwithnickel,   titanium,copper,andberyllium.Itisusedinthe 7  headsofsomebrandsofgolfclubs.Traditional |%  metalclubheadsmayhavemicroscopicgapswhere j  planesofmetalliccrystalsmeet.Thesetinygaps   areapotentialsourceofweakness.Theamorphous K alloyisnoncrystalline,sothemetalstructuredoes 9 nothavepotentialbreakagesites.x^݌ ~ Ќ ' X!  X!'   Read:Semiconductors(makeownnotes) . ЀPage272273 s Practice:Questionspage273274   Ѐ#2(a)(c)(d)(f),3,5(a)(b),7,9 B" Questions:page276 $u" Ѐ#2,6,7,9, &# ̀E.ENDOFTHISCHAPTER!!!!! %+(  BEPREPAREDFORACHAPTERTEST!!!! k.," ЇREADYFORAUNITTEST?!!!! F %EEEE     %  SUMMARYTABLE:TYPESOFCRYSTALLINE  SOLIDS% ݌ 0 Ќ  EEEE   *34 ddd Xdd Xdd X!!,fN,qfN,}fN,.fN,fN,4ff+  8555'vv 8.E Typeof  solid =555,!*!"555 =Unit  Particle =555,!*!"555 =Typeof  Bonding =555,!*!"555 =Melting  Point =555,!*!"555 =Electrical  Conductivity ?5555,!*!"555 ?Examples <20"   5555 <*67 ddfNqfNq}fN}.fN.fN4ff434!!,fN,qfN,}fN,.fN,fN,4ff+  8555'"0 "0  8Ionic =555,!"H "555 =Ion(ve "H  and!ve) =555,!#! "555 =Ionic =555,!"H !"555 =High "H " >10000C =555,!#!#"555 =No "H $ (molten:yes) ?5555,!#!%"555 ?NaCl,KBr, "H & Na2CO3<20#!'"   5555 <*89 ddfNqfNq}fN}.fN.fN4ff467!!,fN,qfN,}fN,.fN,fN,4ff+  8555'A%"'A%" 8Covalent Y%#( (network) =555,!&G$)"555 =Atom Y%#* (molecules) =555,!&G$+"555 =Shared Y%#, pairsof &G$- electrons =555,!'%."555 =Very Y%#/ High &G$0 >20000C =555,!'%1"555 =No ?5555,!Y%#2"555 ?Diamond, Y%#3 quartz &G$4 (SiO2), '%5 carborundu ()&6 m(silicon m*(7 carbide)<20+[)8"   5555 <*:; ddfNqfNq}fN}.fN.fN4ff489!!,fN,qfN,}fN,.fN,fN,4ff+  8555'-*8-* 8 ....      )  Metallic ))  )Ԍ =555,!'-*9 555 =Ќ  ....    Atomic '-*: kernel(+ve l.,; ion) =555,!o"555 =Seaof '-* Electrons l., (+veions o with ] electron  cloud) =555,!>"555 =High '-* >10000C l.,  =555,!o"555 = ....      ,  Yes ,-  -Ԍ '-*  ?5555,!o 555 ?Ќ  ....    Copper, '-* Iron,Tin, l., Lead<20o"   5555 <*<= ddfNqfNq}fN}.fN.fN4ff4:;!!,fN,qfN,}fN,.fN,fN,4ff+  8555'DD 8Molecular =555,!\"555 =Molecule =555,!\"555 =Dipolar \ attraction  !dipole =  dipole  +  attractions  p  ЄLondon    Forces Q  ЄHbonding =555,!? "555 =Low \  <10000C =555,! "555 = ....      92  No 922  2Ԍ ?5555,!\ 555 ?Ќ  ....    Organic \ Solids(HCl,  SO2,N2,Ar, =  CH4,H2O)<20 + "   5555 <X5X.XkwXXX5