专业英语选读课件

化学信息学主讲：杨正银教授

3.1专业英语选读一.

讲授内容第一编：化学专业英语1.化学物质命名2.专业英语选读和英文摘要第二编：化学信息学1.绪论2.印刷版CA查阅3.化学信息资源数据库4.分子的线性表示5.常用化学软件介绍6.数据分析7.CA检索实习3.1专业英语选读二.

本课程应达到的目标1.能认识常见的化合物英文名，会写英文名和摘要2.会查印刷版CA.3.至少掌握两个化学信息资源数据库

能通过Internet检索电子文献.4.学会常见1-2种化学软件使用方法.5.掌握化学信息学基本概念。6.掌握一元数据分析方法，了解分子的线性表示。3.1专业英语选读三.参考书1.化学信息学教程，Gasteiger,JandEngel,T编著（德文）（梁逸曾，徐峻，姚建华等译），化工出版社，2005年2.化学专业英语，马永祥等编，兰大出版社，1997年3.化学信息学，邵学广和蔡文生编科学出版社，2002年3.1专业英语选读几点要求:认真抄笔记!不许随便缺课,课堂作业记作平时成绩!缺课者课后补交课堂作业不计成绩,如果有人代别人抄课堂作业,一旦发现全部记作零分!3.1专业英语选读

ChapterI.

NomenclatureofcompoundsSectionI.Inorganiccompounds3.1专业英语选读NameSymbolNo.汉语名ActiniumAc89锕Aluminum*Al13铝AmericiumAm95嵋Antimony*Sb51锑Argon*Ar18氩Arsenic*As33砷Astatine*At85砹Barium*Ba56钡BerkeliumBk97锫Beryllium*Be4铍Bismuth*Bi83铋Boron*B5硼Bromine*Br35溴Cadmium*Cd48镉Calcium*Ca20钙CaliforniumCf98锎Carbon*C6碳CeriumCe58铈Cesium*Cs55铯一.NAMEOFTHEELEMENTS3.1专业英语选读Chlorine*Cl17氯Chromium*Cr24铬Cobalt*Co27

钴Copper*Cu29铜CuriumCm96锔DysprosiumDy66镝EinsteiniumEs99锿ErbiumEr68铒EuropiumEu63铕FermiumFm100镄Fluorine*F9氟FranciumFr87钫GadoliniumGd64钆Gallium*Ga31镓Germanium*Ge32锗Gold*Au79金HafniumHf72铪Helium*He2氦HolmiumHo67钬Hydrogen*H1氢3.1专业英语选读Indium*In49铟Iodine*I53碘IridiumIr77铱Iron*Fe26铁Krypton*Kr36氪LanthanumLa57镧LawrenciumLr103铹Lead*Pb82铅Lithium*Li8锂LutetiumLu71镥Magnesium*Mg12镁Manganese*Mn25锰MendeleviumMd101钔Mercury*Hg80汞Molybdenum*Mo42钼NeodymiumNd60钕Neon*Ne10氖NeptuniumNp93镎Nickel*Ni28镍Niobium*Nb41铌Nitrogen*N7氮3.1专业英语选读NobeliumNo102锘Osmium*Os76锇Oxygen*O8氧Palladium*Pd46钯Phosphorus*P15磷Platinum*Pt78铂PlutoniumPu94钚PoloniumPo84钋Potassium*K19钾PraseodymiumPr59镨PromethiumPm61钷ProtactiniumPa91镤Radium*Ra88镭Radon*Rn86氡Rhenium*Re75铼Rhodium*Rh45铑Rubidium*Rb37铷Ruthenium*Ru44钌SamariumSm62钐ScandiumSc21钪3.1专业英语选读Selenium*Se34硒Silicon*Si14硅Silver*Ag47银Sodium*Na11钠Strontium*Sr38锶Sulfur*S16硫Tantalum*Ta73钽Technetium*Tc43锝Tellurium*Te52碲Terbium*Tb65铽Thallium*Tl81铊ThoriumTh90钍ThuliumTm69铥Tin*Sn50锡Titanium*Ti22钛Tungsten*W74钨UraniumU92铀Vanadium*V23钒Xenon*Xe54氙YtterbiumYb70镱Yttrium*Y39钇Zinc*Zn30锌Zirconium*Zr40锆3.1专业英语选读3.1专业英语选读

1997年8月27日，国际纯粹和应用化学联合会发表正式文件，对101～109号元素重新定名。我国在收到国际纯粹和应用化学联合会的文件以后，经全国名词委员会化学名词审定分委员会研究，决定重新拟定101～109号元素的中文名称。

104号元素定名为rutherfordium，元素符号Rf，是为纪念卢瑟福而设；105号元素定名为dubnium，元素符号Db，是为纪念前苏联杜布纳研究所在合成该元素时作出过重要贡献；106号元素定名为seaborgium，元素符号Sg，是为纪念西(喜)博格而设；107号元素定名为bohrium，元素符号Bh，是为纪念玻尔而设。3.1专业英语选读

108号元素

108号元素是1984年在德国达姆施塔特的GSI（德国重离子研究中心）首次发现的,所以其名字叫Hassium,Hs来自拉丁文Hassias,意思是Hesse,中文译名为黑森,是达姆施塔特所在的德国一个州的州名。

现在,来自GSI和9个其他实验室的一个国际科研小组报告了对元素Hassium所做的首次化学研究。准确地说,这些化学研究是在7个Hassium原子上进行的，这些原子是通过镁-26和锔-248的聚变反应每次一个地生成的。Hassium形成一种挥发性氧化物，类似于其同族较轻的锇元素的氧化物,这证实Hassium的行为与预料中元素周期表中第8族成员的行为一致。

Hassium是迄今其化学性质被研究过的最重的元素，这些发现将把对关于元素周期表的预测的实验验证推进到了108号元素。3.1专业英语选读109号元素

1982年8月29日，西德科学家宣布发现了第109号化学元素。第109号元素是人工制造的超铀元素，化学符号109或Une。是西德核子研究中心的明岑贝格科学小组用加速器加速的铁离子轰击铋靶合成的，质量数为266。在长达一星期的轰击合成实验中，只获得了一个新元素原子。他们用测量266109的衰变链子体的方法，最终确证109号元素的合成。1994年5月IUPAC通过一项决议，建议把第109号元素命名为Meitnerium，以纪念奥地利女核物理学家LiseMeitner（莉泽·迈特纳）。第109号化学元素的中文名字为Mt（由中国科学技术名词审定委员会化学名词审定分委员会审定予以公开使用）。

3.1专业英语选读

110号元素

110号元素由德国物理学家安布鲁斯特(Armbrster）领导的研究小组，用镍原子轰击作为靶的铅原子的方法，并从产物中检测到110号元素的存在，该元素的寿命极短，半衰期少于1毫秒。安布鲁斯特领导的研究小组为新元素的发现作出了贡献。他们的重离子研究实验室位于德国达姆施塔特（Darmstadt）城，故该小组向IUPAC提交了新元素名称和符号的申请，并遵循IUPAC的命名方法，将他们所在的城市名称加后缀“ium”作为该元素的名称。其符号采用了全称中的两个字母。这个申请在2003年8月16日，在加拿大渥太华召开的IUPAC第42届大会上，得到正式推荐。将第110号元素的英文名称正式确定为Darmstadtium，元素符号为Ds。中文名。

3.1专业英语选读111号元素经过长期审定2003年10月15日

国际理论和应用化学联合会认定，德国达姆施塔特重离子研究所的科学家发现了第111号元素。重离子研究所的科学家西古德·霍夫曼与同事早在1994年就利用镍元素和铋元素进行对撞实验，观测到了三个衰变系，据此发现了第111号元素的存在。

IUPAC2004年颁布第111号化学元素符号为Rg，名称为roentgenium。命名理据是为纪念发现X射线（亦称“伦琴射线”）的科学家WilhelmConradRoentgen。

第111号化学元素的中文定名读音为lún；字形采用“钅仑”。

3.1专业英语选读

第112号元素

早在1996年，德国重离子研究中心（GSI）的西格德·霍夫曼教授领导的国际研究小组就利用重离子研究中心的120英里粒子加速器创造了第112号元素的第一个原子，他们用锌离子轰击铅靶，锌铅原子核经过聚变反应融合形成新元素的原子核。2002年，他们已能生产出另一个原子。随后日本理化研究所的加速器实验生产出了更多的第112号元素原子，证明了重离子研究中心的发现。

2010年2月19日哥白尼生日正式命名为“Copernicium”Cn3.1专业英语选读ThefirstformaldefinitionofchemoinformaticswasthatofBrownwhostatedthat“Theuseofinformationtechnologyandmanagementhasbecomeacriticalpartofthedrugdiscoveryprocess.Chemoinformaticsisthemixingofthoseinformationresourcestotransformdataintoinformationandinformationintoknowledgefortheintendedpurposeofmakingbetterdecisionsfasterintheareaofdrugleadidentificationandoptimization”,adefinitionthattiesthesubjectverycloselytothepharmaceuticalindustrywheremanyofthekeydevelopmentshavetakenplace.AmoregeneraldefinitionisthatofParis,ascitedbyWarr:“Chem(o)informaticsisagenerictermthatencompassesthedesign,creation,organization,management,retrieval,analysis,dissemination,visualizationanduseofchemicalinformation”.Mostrecently,Gasteigerhasreferredtoitas“theapplicationofinformaticsmethodstothesolutionofchemicalproblems”.3.1专业英语选读

化学信息学还没有统一的被广泛接受的定义及英文名称。目前最通用的为Chemoinformatics及Chemicalinformatics。也有用Cheminformatics，Chemiinformatics。也有人把ChemicalinformationScience及MolecularInformatics称为化学信息学。与化学信息学有关的术语有chemi-informatics，chemometrics，computationalchemistry，chemicalinformatics，chemicalinformationmanagement/science，和cheminformatics等等。美国印第安那大学(IndianaUniversity)在国际上最早在化学图书馆科学的基础上开设化学信息课程及培养化学信息学研究生，他们把化学信息学定义为：化学信息学包括从利用传统的图书馆科学方法组织化学信息到利用现代计算机技术产生、存储、检索及可视化化学信息。3.1专业英语选读定义1：FrankBrown于1998年把化学信息学定义为：把各种化学信息源数据组合为信息，把信息提升为知识，其主要目的是在药物先导化合物的发现及优化领域快速地更好地做出决定。这个定义太偏重于药物化学，事实上，化学信息学在其他领域如农业化学也有广泛的应用。(“Theuseofinformationtechnologyandmanagementhasbecomeacritical(决定性的）partofthedrugdiscoveryprocess.Chemoinformaticsisthemixingofthoseinformationresourcestotransformdataintoinformationandinformationintoknowledgefortheintendedpurposeofmakingbetterdecisionsfasterintheareaofdrugleadidentificationandorganization”FKBrown,AnnualReportsinMedicinalChemistry,33,375-384(1998))3.1专业英语选读

定义2：

M.Hann和R.Green认为化学信息学是处理化学老问题的一种新名称（“Chemoinformatics-anewnameforanoldproblem”，CurrentOpinioninChemicalBiology,3,379-383(1999)）。定义3：

GregParis在1999年8月的ACS会议上提出了一个更一般性的定义，他认为：化学信息学是个一般的术语，它包括化学信息的设计、建立、组织、管理、检索、分析、判别、可视化及使用。(“Chem(o)informaticsisagenerictermthatencompassesthedesign,creation,organization,management,retrieval,analysis,dissemination,visualizationanduseofchemicalinformation”G.Paris(August1999ACSmeeting))。

3.1专业英语选读3.1THECHEMICALELEMENTSThenumberofprotonsinthenucleusofanatomisreferredtoastheatomicnumber,orprotonnumber,Z.Thenumberofelectronsinanelectricallyneutralatomisalsoequaltotheatomicnumber,Z.Thetotalmassofanatomisdeterminedverynearlybythetotalnumberofprotonsandneutronsinitsnucleus.Thistotaliscalledthemassnumber,A.Thenumberofneutronsinanatom,theneutronnumber,isgivenbythequantityA-Z.Thetermelementreferstoapuresubstancewithatomsallofasinglekind.Tothechemistthe“kind”ofatomisspecifiedbyitsatomicnumber,sincethisisthepropertythatdeterminesitschemicalbehavior.AtpresentalltheatomsfromZ=1toZ=107areknown;thereare107(112)chemicalelements.Eachchemicalelementhasbeengiven3.1专业英语选读

化学元素的命名规律化学元素的汉语名称的造字、读音一般都有其规律。在汉语里，化学元素的名称都是用一个汉字来表达的。有一些是沿用固有文字的，如，金、银、铜、铁、锡、铅等；有的是根据固有的字改变或增加偏旁而成为化学专用名称的，如镭、铑等；有的是从译音而创造的，如钠、锰、钙等；有的是译意的，如轻气、养气、淡气等，后来又演变成氢、氧、氮，仍保持原字的读音。为了便于识别，现在我国通用的化学元素汉语名称里，凡金属元素除汞外均写作“钅”字旁，非金属元素则依其单质在通常状态下存在状态，分别加“气”、“氵”或“石”等偏旁。化学元素的读音，一般都是按偏旁字来发音的。例如镁读作“美”，氟读作“弗”(fú)，碘读作“典”等等。但也有不少例外，如氧读作“养”，钠读作“纳”，溴读作“嗅”。有些元素名称常被读错，例如，铬应读作“各”，却常误读为“洛”；氯应读“绿”(lǜ)；却常误读为“碌”(lù)；氙本应读“仙”，却常误读为“山”。

3.1专业英语选读anameandadistinctivesymbol.FormostelementsthesymbolissimplytheabbreviatedformoftheEnglishnameconsistingofoneortwoletters,forexample:Oxygen=Onitrogen=Nneon=Nemagnesium=MgSomeelements,whichhavebeenknownforalongtime,havesymbolsbasedontheirLatinnames,forexample:iron=Fe(ferrum)copper=Cu(cuprum)lead=Pb(plumbum)AfewelementshavesymbolsbasedontheLatinnameofoneoftheircompounds,theelementsthemselveshavingbeendiscoveredonlyinrelativeyrecenttimes,forexample:Soidum=Na(natrium=sodiumcarbonate)Potassium=K(kalium=potassiumcarbonate)GoldAu(Aurum)SilverAg(Argentum)TinSn(Stannum)NickelNi(Niccolum)3.1专业英语选读

化学元素的外文名称，在命名时，往往都是有一定含义的。有的是根据元素的某些特性而命名的，例如氧的拉丁文名称是Oxygenium，意思是“成酸的元素”；氮的拉丁文名称是Nitrogenium,意思是“无益于生命”；其他如氯Chlorine(绿色，因为氯是黄绿色气体)、溴Bromine(原意是恶臭)、铯Cesium(天蓝色的意思，因为铯的光谱线中有一条天蓝色谱线)。有的元素名称往往表示它是从什么物质里分离出来的。例如钠从苏打中来，定名Sodium，而拉丁文是Natrium；钾从草木灰中来，定名Potassium,而拉丁文是Kalium。3.1专业英语选读

有的元素为纪念发现者的祖国、故乡而命名。例如，钋Po(Polonium，居里夫人的祖国──波兰)、镓Ga(Gallium，镓的发现者布瓦博德朗是法国人，法国的古称是“家里亚”)、锗Ge(Germanium，德国)、钌Ru(Ruthenium，俄罗斯)、铕Eu(Europium，欧洲)、镅Am(Americium，美洲)，等等。有的元素以科学家的姓氏命名，以纪念某位科学家。例如，锔Cm(Curium，居里夫妇)、锿Es(Einsteinium，爱因斯坦)、钔Md(Mendelevium，门捷列夫)，等等。有以星球命名的化学元素，如：氦He(Helium，太阳，这是因为天文学家从观察太阳光的谱线最早发现太阳里有氦，尔后才在地球上找到氦)、铀U(Uranium，天王星的意思，这是因为铀的发现，正值天王星被发现后不久)，等等。

3.1专业英语选读

此外还有一些以“神”名命名的元素。如：钷Pm(Promethium，这个字来源于希腊神普罗米修斯，传说他从天上窃取火种送到人间。比喻从原子反应堆产物里得到钷，标志着人类进入了原子能时代)。自第103号元素铹Lr(纪念美国物理学家，回旋粒子加速器的发明者劳伦斯)以后，科学家对新元素的命名时而产生分歧意见，例如第104号元素，苏联人命名为Ku，借以纪念苏联核物理学家库尔查多夫，但美国人则命其名为Ru，借以纪念原子物理学家卢瑟福，以后还有第105号元素命名之争，结果这些元素的命名哪个也未取得国际科学界的公认。3.1专业英语选读Acompletelistingoftheelementsmaybefoundintable1.Allatomsofagivenelementmusthavethesameatomicnumber,buttheymayhavedifferentmassnumbers.Thedifferentnuclidesofanelementarereferredtocollectivelyasisotopesoftheelement.InSection2-7,wherethediscoveryandcharacterizationofisotopeswasdiscussed,itwaspointedoutthatthereisonetypeofneonatomwithamass22/20asgreatasthepredominantatomicspecies.Actuallythreedifferentnuclidesexist;therearethreeisotopesofneon,Bysymbol,theseare2010Ne,2110Ne,and2210Ne.Thenaturalabundancesofthesenuclidesare90.9,0.3and8.8%,respectively.Sometimesthemassnumbersofisotopesareincorporatedintothenamesofelements,3.1专业英语选读suchasneon-20,carbon-12andoxygen-16.Inaneutralatomthenumberofelectronsmustbeequaltothenumberofprotons,Z.Butifanatomeitherlosesorgainselectrons,itacquiresanetelectriccharge,itbecomesanion.Thespecies2010Ne+and2010Ne2+areions.Thefirstonehastenprotons,tenneutrons,andnineelectrons,thesecond,tenprotons,tenneutrons,andeightelectrons.3.1专业英语选读1.THENONMETALELEMENTSWenotedearlierthatnonmetalsexhibitpropertiesthataregreatlydifferentfromthoseofthemetals.Asarule,thenonmetalsarepoorconductorsofelectricity(graphiticcarbonisanexception)andheat;theyarebrittle,areoftenintenselycolored,andshowanunusuallywiderangeofmeltingandboilingpoints.Theirmolecularstructures,usuallyinvolvingordinarycovalentbonds,varyfromthesimplediatomicmoleculesofH2,Cl2,I2andN2tothegiantmoleculesofdiamond,siliconandboron.3.1专业英语选读Thenonmetalsthataregasesatroomtemperaturearethelow-molecularweightdiatomicmoleculesandthenoblegasesthatexertverysmallintermolecularforces.Asthemolecularweightincreases,weencounteraliquid(Br2)andasolid(I2)whosevaporpressuresalsoindicatesmallintermolecularforces.CertainpropertiesofafewnonmetalsarelistedinTable2.3.1专业英语选读Table2.MolecularweightsandMeltingPointsofCertainNonmetalsDiatomicMolecules MolecularWeight MeltingPoint℃Color H2 2 -259.1 None N2 28 -210 None F2 38 -223 Paleyellow O2 32 -218 Paleblue Cl2 71 -102 Yellow-green Br2 160 -7.3 Red-brown I2 254 113 Gray-black 3.1专业英语选读SimplediatomicmoleculesarenotformedbytheheaviermembersofGroupsVandVIandatordinaryconditions.Thisisindirectcontrasttothefirstmembersofthesegroups,N2andO2.Thedifferencearisesbecauseofthelowerstabilityofπbondsformedfromporbitalsofthethirdandhighermainenergylevelsasopposedtothesecondmainenergylevel.Thelargeratomicradiiandmoredenseelectroncloudsofelementsofthethirdperiodandhigherdonotallowgoodparalleloverlapofporbitalsnecessaryforastrongπbond.Thisisageneralphenomenon—strongπbondsareformedonlybetweenelementsofthesecondperiod.Thus,elementalnitrogenandoxygenformstablemoleculeswithbothσandπbonds,butothermembersoftheirgroupsformmorestablestructuresbasedonσbondsonlyatordinaryconditions.NotethatGroupVIIelementsformdiatomicmolecules,butπbondsarenotrequiredforsaturationofvalence.3.1专业英语选读Sulfurexhibitsallotropicforms.Solidsulfurexistsintwocrystallineformsandinanamorphousform.Rhombicsulfurisobtainedbycrystallizationfromasuitablesolution,suchasCS2,anditmeltsat112℃.Monoclinicsulfurisformedbycoolingmeltedsulfuranditmeltsat119℃.BothformsofcrystallinesulfurmeltintoS-gamma,whichiscomposedofS8molecules.TheS8moleculesarepuckeredringsandsurviveheatingtoabout160℃.Above160℃,theS8ringsbreakopen,andsomeofthesefragmentscombinewitheachothertoformahighlyviscousmixtureofirregularlyshapedcoils.Atarangeofhighertemperaturestheliquidsulfurbecomessoviscousthatitwillnotpourfromitscontainer.Thecoloralsochangesfromstrawyellowatsulfur’smeltingpointtoadeepreddishbrownasitbecomesmoreviscous.3.1专业英语选读

Astheboilingpointof444℃isapproached,thelarge-coiledmoleculesofsulfurarepartiallydegradedandtheliquidsulfurdecreasesinviscosity.Ifthehotliquidsulfurisquenchedbypouringitintocoldwater,theamorphousformofsulfurisproduced.Thestructureofamorphoussulfurconsistsoflarge-coiledheliceswitheightsulfuratomstoeachturnofthehelix;theoverallnatureofamorphoussulfurisdescribedasrubberybecauseitstretchesmuchlikeordinaryrubber.Inafewhourstheamorphoussulfurrevertstosmallrhombiccrystalsanditsrubberypropertydisappears.3.1专业英语选读Sulfur,andimportantrawmaterialinindustrialchemistry,occursasthefreeelement,asSO2involcanicregions,asH2Sinmineralwaters,andinavarietyofsulfideoressuchasironpyritesFeS2,zincblendeZnS,galenaPbS,andincommonformationsofgypsumCaSO4·2H2O,anhydriteCaSO4,andbarytesBaSO4·2H2O.Sulfur,inoneformoranother,isusedinlargequantitiesformakingsulfuricacidfertilizers,insecticides,andpaper.SulfurintheformofSO2obtainedintheroastingofsulfideoresisrecoveredandconvertedtosulfuricacid,althoughinpreviousyearsmuchofthisSO2wasdiscardedthroughexceptionallytallsmokestacks.Fortunately,itisnoweconomicallyfavorabletorecoverthesegases,thusgreatlyreducingthistypeofatmosphericpollution.Atypicalroastingreactioninvolvesthechange.kk:abandon,getridof,3.1专业英语选读2ZnS+3O2→2ZnO+2SO2Phosphorus,below800℃,consistsoftetratomicmolecules,P4.Itsmolecularstructureprovidesforacovalenceofthree,asmaybeexpectedfromthethreeunpairedpelectronsinitsatomicstructure,andeachatomisattachedtothreeothers.Insteadofastrictlyorthogonalorientation,withthethreebonds90

toeachother,thebondanglesareonly60

.Thissupposedlystrainedstructureisstabilizedbythemutualinteractionofthefouratoms(eachatomisbondedtotheotherthree),butitischemicallythemostactiveformofphosphorus.Thisformofphosphorus,thewhitemodification,isspontaneouslycombustibleinair.Whenheatedto260℃itchangestoredphosphorus,whosestructureisobscure.Redphosphorusisstableinairbut,likeallformsof

kk:Indefinite,unclearreciprocal3.1专业英语选读phosphorus,itshouldbehandledcarefullybecauseofitstendencytomigratetotheboneswheningested,resultinginseriousphysiologicaldamage.Elementalcarbonexistsinoneoftwocrystallinestructures-diamondandgraphite.Thediamondstructure,basedontetrahedralbondingofhybridizedsp3orbitals,isencounteredamongGroupIVelements.Wemayexpectthatasthebondlengthincreases,thehardnessofthediamondtypecrystaldecreases.Althoughthetetrahedralstructurepersistsamongtheelementsinthisgroup-carbon,silicon,germanium,andgraytin-theinteratomicdistancesincreasefrom1.54Åforcarbonto2.80Åforgraytin.Consequently,thebondstrengthsamongthefourelementsrangekk:administer3.1专业英语选读fromverystrongtoquiteweak.Infact,graytinissosoftthatitexistsintheformofmicrocrystalsormerelyasapowder.TypicaloftheGroupIVdiamond-typecrystallineelements,itisanonconductorandshowsothernonmetallicproperties.2.GROUPSIBANDIIBELEMENTS2.1PhysicalpropertiesofGroupIBandIIBTheseelementshaveagreaterbulkuseasmetalsthanincompounds,andtheirphysicalpropertiesvarywidely.Goldisthemostmalleableandductileofthemetals.Itcanbehammeredintosheetsof0.00001inchinthickness;onegramofthemetalcanbedrawnintoawire1.8mi(mile)inlength.Copperandsilverarealsometalsthataremechanicallyeasytowork.Zincisalittlebrittleatordinary3.1专业英语选读temperatures,butmayberolledintosheetsatbetween120

to150℃;itbecomesbrittleagainabout200℃.Thelow-meltingtemperaturesofzinccontributetothepreparationofzinc-coatediron,galvanizediron;cleanironsheetmaybedippedintovatsofliquidzincinitspreparation.Adifferentprocedureistosprinkleorairblastzincdustontohotironsheetingforazincmeltandthencoating.Cadmiumhasspecificusesbecauseofitslow-meltingtemperatureinanumberofalloys.Cadmiumrodsareusedinnuclearreactorsbecausethemetalisagoodneutronabsorber.Mercuryvaporanditssaltsarepoisonous,thoughthefreemetalmaybetakeninternallyundercertainconditions.Becauseofitsrelativelylowboilingpointandhencevolatilenature,free3.1专业英语选读mercuryshouldneverbeallowedtostandinanopencontainerinthelaboratory.Evidenceshowsthatinhalation(吸入）ofitsvaporsisinjurious.Themetalalloysreadilywithmostofthemetals(exceptironandplatinum)toformamalgams,thenamegiventoanyalloyofmercury.Coppersulfate,orbluevitriol(CuSO4·5H2O)isthemostimportantandwidelyusedsaltofcopper.Onheating,thesaltslowlyloseswatertoformfirstthetrihydrate(CuSO4·3H2O),thenthemonohydrate(CuSO4·H2O),andfinallythewhiteanhydroussalt.Theanhydroussaltisoftenusedtotestforthepresenceofwaterinorganicliquids.Forexample,someoftheanhydrouscoppersaltaddedtoalcohol(whichcontainswater)willturnbluebecauseofthehydrationofthesalt.3.1专业英语选读Coppersulfateisusedinelectroplating.Fishermendiptheirnetsincoppersulfatesolutiontoinhibitthegrowthoforganismsthatwouldrotthefabric.Paintsspecificallyformulatedforuseonthebottomsofmarinecraftcontaincoppercompoundstoinhibitthegrowthofbarnacles(藤壶)andotherorganisms.Whendiluteammoniumhydroxideisaddedtoasolutionofcopper(II)ions,agreenishprecipitateofCu(OH)2orabasiccopper(II)saltisformed.Thisdissolvesasmoreammoniumhydroxideisadded.Theexcessammoniaformsanammoniatedcomplexwiththecopper(II)ionofthecomposition,Cu(NH3)42+.Thisionisonlyslightlydissociated;henceinanammoniacalsolutionveryfewcopper(II)ionsarepresent.iron(II)disulfideTetraamminecopper(II)Copper(II)hydroxide3.1专业英语选读Insolublecoppercompounds,exceptcoppersulfide,aredissolvedbyammoniumhydroxide.Theformationofthecopper(II)ammoniaionisoftenusedasatestforCu2+becauseofitsdeep,intensebluecolor.Copper(II)ferrocyanide[Cu2Fe(CN)6]isobtainedasareddish-brownprecipitateontheadditionofasolubleferrocyanidetoasolutionofcopper(II)ions.Theformationofthissaltisalsousedasatestforthepresenceofcopper(II)ions.CompoundsofSilverandGoldSilvernitrate,Sometimescalledlunarcaustic(医用硝酸银),isthemostimportantsaltofsilver.Itmeltsreadilyandmaybecastintosticksforuseincauterizingwounds.Thesaltispreparedbydissolvingsilverinnitricacidandevaporatingthesolution.)Copper(II)hexacyanoferrate(II)3.1专业英语选读

3Ag+4HNO3→NO+2H2O+3AgNO3Thesaltisthestartingmaterialformostofthecompoundsofsilver,includingthehalidesusedinphotography.Itisreadilyreducedbyorganicreducingagents,withtheformationofablackdepositoffinelydividedsilver;thisactionisresponsibleforblackspotsleftonthefingersfromthehandlingofthesalt.Indelible(擦不掉的)markinginksandpencilstakeadvantageofthispropertyofsilvernitrate.Thehalidesofsilver,exceptthefluoride,areveryinsolublecompoundsandmaybeprecipitatedbytheadditionofasolutionofsilversalttoasolutioncontainingchloride,bromide,oriodideions.Theadditionofastrongbasetoasolutionofasilversaltprecipitatesbrownsilveroxide(Ag2O).OnemightexpecttheNitricacidnitrogenmonoxidesilvernitratepermanent3.1专业英语选读hydroxideofsilvertoprecipitate,butitseemslikelythatsilverhydroxideisveryunstableandbreaksdownintotheoxideandwater–if,indeed,itiseverformedatall.However,sinceasolutionofsilveroxideisdefinitelybasic,theremustbehydroxideionspresentinsolution.Ag2O+H2O=2Ag++2OH-Becauseofitsinactivity,goldformsrelativelyfewcompounds.Twoseriesofcompoundsareknown–monovalentandtrivalent.Monovalent(aurous)compoundsresemblesilvercompounds(aurouschlorideiswaterinsolubleandlightsensitive),whilethehighervalence(auric)compoundstendtoformcomplexes.Goldisresistanttotheactionofmostchemicals-air,oxygenandwaterhavenoeffective.Thecommonacidsdonotattackthemetal,butamixtureofhydrochloricandnitricacids(aquaregia)dissolvesittoformgold(III)chlorideorchloroauricacid.3.1专业英语选读Theactionisprobablyduetofreechlorinepresentintheaquaregia.(Nitrogen(III)oxidechloride)3HCl+HNO3→NOCl+Cl2+2H2O2Au+3Cl2→2AuCl3

AuCl3+HCl→HAuCl4(chloroauricacid)CompoundsofZincZincisfairlyhighintheactivityseries.Itreactsreadilywithacidstoproducehydrogenanddisplaceslessactivemetalsfromtheirsalts.Theactionofacidsonimpurezincismuchmorerapidthanonpurezinc,sincebubblesofhydrogengascollectonthesurfaceofpurezincandslowdowntheaction.Ifanothermetalispresentasanimpurity,thehydrogenisliberatedfromthesurfaceofthecontaminatingmetalratherthanfromthezinc.3.1专业英语选读Anelectriccoupletofacilitatetheactionisprobablysetupbetweenthetwometals.Zn+2H+→Zn2++H2Zincoxide(ZnO),themostwidelyusedzinccompounds,isawhitepowderatordinarytemperatures,butchangestoyellowonheating.Whencooled,itagainbecomeswhite.Zincoxideisobtainedbyburningzincinair,byheatingthebasiccarbonate,orbyroastingthesulfide.TheprincipaluseofZnOisasafillerinrubbermanufacture,particularlyinautomobiletires.Asabodyforpaintsithastheadvantageoverwhiteleadofnotdarkeningonexposuretoanatmospherecontaininghydrogensulfide.Itscoveringpower,however,isinferiorto(superiorto)thatofwhitelead.3.1专业英语选读3.GROUPⅢB—ⅧBELEMENTSGroupⅢBincludestheelementsscandium,yttrium,lanthanum,andactinium,andthetworare-earthseriesoffourteenelementseach-thelanthanideandactinideseries.Theprincipalsourceoftheseelementsisthehighgravityriverandbeachsandsbuiltupbyawater-sortingprocessduringlongperiodsofgeologictime.Monazitesand,whichcontainsamixtureofrareearthphosphates,andanyttriumsilicateinaheavysandarenowcommercialsourcesofanumberofthesescarceelements.Separationoftheelementsisadifficultchemicaloperation.Thesolubilitiesoftheircompoundsaresonearlyalikethataseparationbyfractionalcrystallizationislaboriousandtime-consuming.Inrecentyears,ionexchangeresinsinhighcolumnshaveprovedeffective.3.1专业英语选读WhencertainacidsareallowedtoflowdownslowlythroughacolumncontainingaresintowhichionsofGroupⅢBmetalsareadsorbed,ionsaresuccessivelyreleasedfromtheresin.Theresultingsolutionisremovedfromthebottomofthecolumnortowerinbandsorsections.Successivesectionswillcontainspecificionsintheorderofreleasebytheresin.Forexample,lanthanumion(La3+)ismosttightlyheldtotheresinandisthelasttobeextracted,lutetiumion(Lu3+)islesstightlyheldandappearsinoneofthefirstsectionsremoved.Ifthesolutionsarerecycledandtheacidconcentrationscarefullycontrolled,veryeffectiveseparationscanbeaccomplished.Quantitiesofallthelanthanideseries(exceptpromethium,Pm,whichdoesnotexistinnatureasastableisotope)areproducedforthechemicalmarket.3.1专业英语选读Thepredominantgroupoxidationnumberofthelanthanideseriesis+3,butsomeoftheelementsexhibitvariableoxidationstates.Ceriumformscerium(III)andcerium(IV)sulfates,Ce2(SO4)3andCe(SO4)2,whichareemployedincertainoxidation-reductiontitrations.Manyrareearthcompoundsarecoloredandareparama