Transition elements

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1、Transitionelements1.IntroductionTransitionelementCIE官义:a(d-block)elementformingstableions/compounds/oxidationstateswithincomplete/partiallyfilled[NOTempty]d-orbitalsEdexcel官义:Formsion(s)whichhaveapartiallyORanincompletelyfilledd-(sub)shellORd-orbital(s)

2、WedonotdefineScandZnastransitionelementsbecause:Scandiumformsonlyoneion(Sc3+)andthishasnoelectronsinits3dsub-shell—theelectronicconfigurationofSc3+is(Ar)3d04s0.Zincformsonlyoneion(Zn2+)andthishasacomplete3dsub-shell—theelectronicconfigurationofZn2+is(

3、Ar)3d104s0.TransitionmetalcharacteristicsareCIE标答:Colouredcompounds/ions/solutions/pptsParamagneticVariableoxidationstate/valency/morethanoneionDensemetalsHighmeltingpointmetalsArecatalystsFormcomplexesHowdotheatomicradiiofthetransitionelementsva

4、ryfromchromiumtocopper?almostnochange(allowslightincreaseorslightdecrease)Predict,withareason,thevariationinthedensitiesofthetransitionelementsfromchromiumtocopper.densityshouldincreasebecauseArisincreasingbutsize/volume/radiusstaysthesame-Suggestwhytra

5、nsitionelementsshowvariableoxidationstatesintheircompoundswhereass-blockelementslikecalciumdonot.Manyelectronsofsimilarenergyinavalence-shellorbitalorSuccessiveionisationenergiesrisesteadily(nobigjumps)orAbilitytoformbondswithligandscanstabiliseverylowo

6、rveryhighoxidationstatesor4s+3dorbitals/shells/energylevelshavesimilar/sameenergies2.Physicalpropertiesofthetransitionelements-Themeltingpointanddensityofatypicaltransitionelementsuchasirondifferfromthoseofatypicals-blockelementsuchascalcium.Describeand

7、explainthesedifferences.Bothm.p.anddensityofFearehigherthanthoseforCa.M.p.:duetostrongerlattice/bondingormoredelocalisedelectronsDensity:duetoheavieratoms/largerArbutsmallerradius-SuggestareasonwhyironformscompoundscontainingFe3+ionsaswellascompoundscon

8、tainingFe2+ions,whereascalciumonlyformscompoundscontainingCa2+ions.ThethirdIEisnotmuchgreaterthanthesecondIEforiron.OrforCathethirdIEismuchgreaterthanthesecondIEOrFecanuse/ionised-electronsaswellas4selectronsOrdandselectrons/orbi