資源描述：
《Transition elements》由會員上傳分享，免費在線閱讀，更多相關(guān)內(nèi)容在學術(shù)論文-天天文庫。
1、Transitionelements1.IntroductionTransitionelementCIE官義:a(d-block)elementformingstableions/compounds/oxidationstateswithincomplete/partiallyfilled[NOTempty]d-orbitalsEdexcel官義: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標答:?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
