化學(xué)專業(yè)英語選讀

化學(xué)信息學(xué)主講：楊正銀教授

一.

講授內(nèi)容第一編：化學(xué)專業(yè)英語1.化學(xué)物質(zhì)命名2.專業(yè)英語選讀第二編：化學(xué)信息學(xué)1.緒論2.印刷版CA查閱3.化學(xué)信息資源數(shù)據(jù)庫4.分子的線性表示5.常用化學(xué)軟件介紹6.數(shù)據(jù)分析7.CA檢索實習(xí)二.

本課程應(yīng)達到的目標(biāo)1.能認(rèn)識常見的化合物英文名，會寫英文名2.會查印刷版CA.3.至少掌握兩個化學(xué)信息資源數(shù)據(jù)庫

能通過Internet檢索電子文獻.4.學(xué)會常見1-2種化學(xué)軟件使用方法.5.掌握化學(xué)信息學(xué)基本概念。6.掌握一元數(shù)據(jù)分析方法，了解分子的線性表示。三.參考書1.化學(xué)信息學(xué)教程，Gasteiger,JandEngel,T編著（德文）（梁逸曾，徐峻，姚建華等譯），化工出版社，2005年2.化學(xué)專業(yè)英語，馬永祥等編，蘭大出版社，1997年3.化學(xué)信息學(xué)，邵學(xué)廣和蔡文生編科學(xué)出版社，2002年幾點要求:認(rèn)真抄筆記!不許隨便缺課,課堂作業(yè)記作平時成績!缺課者課后補交課堂作業(yè)不計成績,如果有人代別人抄課堂作業(yè),一旦發(fā)現(xiàn)全部記作零分!

ChapterI.

NomenclatureofcompoundsNAMEOFTHEELEMENTSNameSymbolNo.漢語名ActiniumAc89錒Aluminum*Al13鋁AmericiumAm95嵋Antimony*Sb51銻Argon*Ar18氬Arsenic*As33砷Astatine*At85砹Barium*Ba56鋇BerkeliumBk97锫Beryllium*Be4鈹Bismuth*Bi83鉍Boron*B5硼B(yǎng)romine*Br35溴Cadmium*Cd48鎘Calcium*Ca20鈣CaliforniumCf98锎Carbon*C6碳CeriumCe58鈰Cesium*Cs55銫一.NAMEOFTHEELEMENTSChlorine*Cl17氯Chromium*Cr24鉻Cobalt*Co27

鈷Copper*Cu29銅CuriumCm96鋦DysprosiumDy66鏑EinsteiniumEs99锿ErbiumEr68鉺EuropiumEu63銪FermiumFm100鐨Fluorine*F9氟FranciumFr87鈁GadoliniumGd64釓Gallium*Ga31鎵Germanium*Ge32鍺Gold*Au79金HafniumHf72鉿Helium*He2氦HolmiumHo67鈥Hydrogen*H1氫Indium*In49銦Iodine*I53碘IridiumIr77銥Iron*Fe26鐵Krypton*Kr36氪LanthanumLa57鑭LawrenciumLr103鐒Lead*Pb82鉛Lithium*Li8鋰LutetiumLu71镥Magnesium*Mg12鎂Manganese*Mn25錳MendeleviumMd101鍆Mercury*Hg80汞Molybdenum*Mo42鉬NeodymiumNd60釹Neon*Ne10氖NeptuniumNp93镎Nickel*Ni28鎳Niobium*Nb41鈮Nitrogen*N7氮NobeliumNo102锘Osmium*Os76鋨Oxygen*O8氧Palladium*Pd46鈀Phosphorus*P15磷Platinum*Pt78鉑PlutoniumPu94钚PoloniumPo84釙Potassium*K19鉀PraseodymiumPr59鐠PromethiumPm61钷ProtactiniumPa91鏷Radium*Ra88鐳Radon*Rn86氡Rhenium*Re75錸Rhodium*Rh45銠Rubidium*Rb37銣Ruthenium*Ru44釕SamariumSm62釤ScandiumSc21鈧Selenium*Se34硒Silicon*Si14硅Silver*Ag47銀Sodium*Na11鈉Strontium*Sr38鍶Sulfur*S16硫Tantalum*Ta73鉭Technetium*Tc43锝Tellurium*Te52碲Terbium*Tb65鋱Thallium*Tl81鉈ThoriumTh90釷ThuliumTm69銩Tin*Sn50錫Titanium*Ti22鈦Tungsten*W74鎢UraniumU92鈾Vanadium*V23釩Xenon*Xe54氙YtterbiumYb70鐿Yttrium*Y39釔Zinc*Zn30鋅Zirconium*Zr40鋯

1997年8月27日，國際純粹和應(yīng)用化學(xué)聯(lián)合會發(fā)表正式文件，對101～109號元素重新定名。我國在收到國際純粹和應(yīng)用化學(xué)聯(lián)合會的文件以后，經(jīng)全國名詞委員會化學(xué)名詞審定分委員會研究，決定重新擬定101～109號元素的中文名稱。

104號元素定名為rutherfordium，元素符號Rf，是為紀(jì)念盧瑟福而設(shè)；105號元素定名為dubnium，元素符號Db，是為紀(jì)念前蘇聯(lián)杜布納研究所在合成該元素時作出過重要貢獻；106號元素定名為seaborgium，元素符號Sg，是為紀(jì)念西(喜)博格而設(shè)；107號元素定名為bohrium，元素符號Bh，是為紀(jì)念玻爾而設(shè)。

108號元素

108號元素是1984年在德國達姆施塔特的GSI（德國重離子研究中心）首次發(fā)現(xiàn)的,所以其名字叫Hassium,Hs來自拉丁文Hassias,意思是Hesse,中文譯名為黑森,是達姆施塔特所在的德國一個州的州名。

現(xiàn)在,來自GSI和9個其他實驗室的一個國際科研小組報告了對元素Hassium所做的首次化學(xué)研究。準(zhǔn)確地說,這些化學(xué)研究是在7個Hassium原子上進行的，這些原子是通過鎂-26和鋦-248的聚變反應(yīng)每次一個地生成的。Hassium形成一種揮發(fā)性氧化物，類似于其同族較輕的鋨元素的氧化物,這證實Hassium的行為與預(yù)料中元素周期表中第8族成員的行為一致。

Hassium是迄今其化學(xué)性質(zhì)被研究過的最重的元素，這些發(fā)現(xiàn)將把對關(guān)于元素周期表的預(yù)測的實驗驗證推進到了108號元素。109號元素

1982年8月29日，西德科學(xué)家宣布發(fā)現(xiàn)了第109號化學(xué)元素。第109號元素是人工制造的超鈾元素，化學(xué)符號109或Une。是西德核子研究中心的明岑貝格科學(xué)小組用加速器加速的鐵離子轟擊鉍靶合成的，質(zhì)量數(shù)為266。在長達一星期的轟擊合成實驗中，只獲得了一個新元素原子。他們用測量266109的衰變鏈子體的方法，最終確證109號元素的合成。1994年5月IUPAC通過一項決議，建議把第109號元素命名為Meitnerium

，以紀(jì)念奧地利女核物理學(xué)家Lise

Meitner

（莉澤·邁特納）。第109號化學(xué)元素的中文名字為Mt（由中國科學(xué)技術(shù)名詞審定委員會化學(xué)名詞審定分委員會審定予以公開使用）。

110號元素

110號元素由德國物理學(xué)家安布魯斯特(Armbrster）領(lǐng)導(dǎo)的研究小組，用鎳原子轟擊作為靶的鉛原子的方法，并從產(chǎn)物中檢測到110號元素的存在，該元素的壽命極短，半衰期少于1毫秒。安布魯斯特領(lǐng)導(dǎo)的研究小組為新元素的發(fā)現(xiàn)作出了貢獻。他們的重離子研究實驗室位于德國達姆施塔特（Darmstadt）城，故該小組向IUPAC提交了新元素名稱和符號的申請，并遵循IUPAC的命名方法，將他們所在的城市名稱加后綴“ium”作為該元素的名稱。其符號采用了全稱中的兩個字母。這個申請在2003年8月16日，在加拿大渥太華召開的IUPAC第42屆大會上，得到正式推薦。將第110號元素的英文名稱正式確定為Darmstadtium，元素符號為Ds。中文名

。

111號元素經(jīng)過長期審定2003年10月15日

國際理論和應(yīng)用化學(xué)聯(lián)合會認(rèn)定，德國達姆施塔特重離子研究所的科學(xué)家發(fā)現(xiàn)了第111號元素。重離子研究所的科學(xué)家西古德·霍夫曼與同事早在1994年就利用鎳元素和鉍元素進行對撞實驗，觀測到了三個衰變系，據(jù)此發(fā)現(xiàn)了第111號元素的存在。

IUPAC2004年頒布第111號化學(xué)元素符號為Rg，名稱為roentgenium。命名理據(jù)是為紀(jì)念發(fā)現(xiàn)X射線（亦稱“倫琴射線”）的科學(xué)家WilhelmConradRoentgen。

第111號化學(xué)元素的中文定名讀音為lún；字形采用“钅侖”。

第112號元素

早在1996年，德國重離子研究中心（GSI）的西格德·霍夫曼教授領(lǐng)導(dǎo)的國際研究小組就利用重離子研究中心的120英里粒子加速器創(chuàng)造了第112號元素的第一個原子，他們用鋅離子轟擊鉛靶，鋅鉛原子核經(jīng)過聚變反應(yīng)融合形成新元素的原子核。2002年，他們已能生產(chǎn)出另一個原子。隨后日本理化研究所的加速器實驗生產(chǎn)出了更多的第112號元素原子，證明了重離子研究中心的發(fā)現(xiàn)。

2010年2月19日哥白尼生日正式命名為“Copernicium”Cn

化學(xué)元素的命名規(guī)律化學(xué)元素的漢語名稱的造字、讀音一般都有其規(guī)律。在漢語里，化學(xué)元素的名稱都是用一個漢字來表達的。有一些是沿用固有文字的，如，金、銀、銅、鐵、錫、鉛等；有的是根據(jù)固有的字改變或增加偏旁而成為化學(xué)專用名稱的，如鐳、銠等；有的是從譯音而創(chuàng)造的，如鈉、錳、鈣等；有的是譯意的，如輕氣、養(yǎng)氣、淡氣等，后來又演變成氫、氧、氮，仍保持原字的讀音。為了便于識別，現(xiàn)在我國通用的化學(xué)元素漢語名稱里，凡金屬元素除汞外均寫作“钅”字旁，非金屬元素則依其單質(zhì)在通常狀態(tài)下存在狀態(tài)，分別加“氣”、“氵”或“石”等偏旁?；瘜W(xué)元素的讀音，一般都是按偏旁字來發(fā)音的。例如鎂讀作“美”，氟讀作“弗”(fú)，碘讀作“典”等等。但也有不少例外，如氧讀作“養(yǎng)”，鈉讀作“納”，溴讀作“嗅”。有些元素名稱常被讀錯，例如，鉻應(yīng)讀作“各”，卻常誤讀為“洛”；氯應(yīng)讀“綠”(lǜ)；卻常誤讀為“碌”(lù)；氙本應(yīng)讀“仙”，卻常誤讀為“山”。

化學(xué)元素的外文名稱，在命名時，往往都是有一定含義的。有的是根據(jù)元素的某些特性而命名的，例如氧的拉丁文名稱是Oxygenium，意思是“成酸的元素”；氮的拉丁文名稱是Nitrogenium,意思是“無益于生命”；其他如氯Chlorine(綠色，因為氯是黃綠色氣體)、溴Bromine(原意是惡臭)、銫Cesium(天藍色的意思，因為銫的光譜線中有一條天藍色譜線)。有的元素名稱往往表示它是從什么物質(zhì)里分離出來的。例如鈉從蘇打中來，定名Sodium，而拉丁文是Natrium；鉀從草木灰中來，定名Potassium,而拉丁文是Kalium。

有的元素為紀(jì)念發(fā)現(xiàn)者的祖國、故鄉(xiāng)而命名。例如，釙Po(Polonium，居里夫人的祖國──波蘭)、鎵Ga(Gallium，鎵的發(fā)現(xiàn)者布瓦博德朗是法國人，法國的古稱是“家里亞”)、鍺Ge(Germanium，德國)、釕Ru(Ruthenium，俄羅斯)、銪Eu(Europium，歐洲)、镅Am(Americium，美洲)，等等。有的元素以科學(xué)家的姓氏命名，以紀(jì)念某位科學(xué)家。例如，鋦Cm(Curium，居里夫婦)、锿Es(Einsteinium，愛因斯坦)、鍆Md(Mendelevium，門捷列夫)，等等。有以星球命名的化學(xué)元素，如：氦He(Helium，太陽，這是因為天文學(xué)家從觀察太陽光的譜線最早發(fā)現(xiàn)太陽里有氦，爾后才在地球上找到氦)、鈾U(Uranium，天王星的意思，這是因為鈾的發(fā)現(xiàn)，正值天王星被發(fā)現(xiàn)后不久)，等等。

此外還有一些以“神”名命名的元素。如：钷Pm(Promethium，這個字來源于希臘神普羅米修斯，傳說他從天上竊取火種送到人間。比喻從原子反應(yīng)堆產(chǎn)物里得到钷，標(biāo)志著人類進入了原子能時代)。自第103號元素鐒Lr(紀(jì)念美國物理學(xué)家，回旋粒子加速器的發(fā)明者勞倫斯)以后，科學(xué)家對新元素的命名時而產(chǎn)生分歧意見，例如第104號元素，蘇聯(lián)人命名為Ku，借以紀(jì)念蘇聯(lián)核物理學(xué)家?guī)鞝柌槎喾颍绹藙t命其名為Ru，借以紀(jì)念原子物理學(xué)家盧瑟福，以后還有第105號元素命名之爭，結(jié)果這些元素的命名哪個也未取得國際科學(xué)界的公認(rèn)。ThefirstformaldefinitionofchemoinformaticswasthatofBrownwhostatedthat“Theuseofinformationtechnologyandmanagementhasbecomeacriticalpartofthedrugdiscoveryprocess.Chemoinformaticsisthemixingofthoseinformationresourcestotransformdataintoinformationandinformationintoknowledgefortheintendedpurposeofmakingbetterdecisionsfasterintheareaofdrugleadidentificationandoptimization”,adefinitionthattiesthesubjectverycloselytothepharmaceuticalindustrywheremanyofthekeydevelopmentshavetakenplace.AmoregeneraldefinitionisthatofParis,ascitedbyWarr:“Chem(o)informaticsisagenerictermthatencompassesthedesign,creation,organization,management,retrieval,analysis,dissemination,visualizationanduseofchemicalinformation”.Mostrecently,Gasteigerhasreferredtoitas“theapplicationofinformaticsmethodstothesolutionofchemicalproblems”.化學(xué)信息學(xué)英文定義化學(xué)信息學(xué)還沒有統(tǒng)一的被廣泛接受的定義及英文名稱。目前最通用的為Chemoinformatics及Chemicalinformatics。也有用Cheminformatics，

Chemiinformatics。也有人把ChemicalinformationScience及MolecularInformatics稱為化學(xué)信息學(xué)。與化學(xué)信息學(xué)有關(guān)的術(shù)語有chemi-informatics，chemometrics，computationalchemistry，chemicalinformatics，chemicalinformationmanagement/science，和cheminformatics等等。美國印第安那大學(xué)(IndianaUniversity)在國際上最早在化學(xué)圖書館科學(xué)的基礎(chǔ)上開設(shè)化學(xué)信息課程及培養(yǎng)化學(xué)信息學(xué)研究生，他們把化學(xué)信息學(xué)定義為：化學(xué)信息學(xué)包括從利用傳統(tǒng)的圖書館科學(xué)方法組織化學(xué)信息到利用現(xiàn)代計算機技術(shù)產(chǎn)生、存儲、檢索及可視化化學(xué)信息。定義1：FrankBrown于1998年把化學(xué)信息學(xué)定義為：把各種化學(xué)信息源數(shù)據(jù)組合為信息，把信息提升為知識，其主要目的是在藥物先導(dǎo)化合物的發(fā)現(xiàn)及優(yōu)化領(lǐng)域快速地更好地做出決定。這個定義太偏重于藥物化學(xué)，事實上，化學(xué)信息學(xué)在其他領(lǐng)域如農(nóng)業(yè)化學(xué)也有廣泛的應(yīng)用。(“Theuseofinformationtechnologyandmanagementhasbecomeacriticalpartofthedrugdiscoveryprocess.Chemoinformaticsisthemixingofthoseinformationresourcestotransformdataintoinformationandinformationintoknowledgefortheintendedpurposeofmakingbetterdecisionsfasterintheareaofdrugleadidentificationandorganization”FKBrown,AnnualReportsinMedicinalChemistry,33,375-384(1998))

定義2：

M.Hann

和R.Green認(rèn)為化學(xué)信息學(xué)是處理化學(xué)老問題的一種新名稱（“Chemoinformatics-anewnameforanoldproblem”，CurrentOpinioninChemicalBiology,3,379-383(1999)）。定義3：

GregParis在1999年8月的ACS會議上提出了一個更一般性的定義，他認(rèn)為：化學(xué)信息學(xué)是個一般的術(shù)語，它包括化學(xué)信息的設(shè)計、建立、組織、管理、檢索、分析、判別、可視化及使用。(“Chem(o)informaticsisagenerictermthatencompassesthedesign,creation,organization,management,retrieval,analysis,dissemination,visualizationanduseofchemicalinformation”G.Paris(August1999ACSmeeting))。

3.1THECHEMICALELEMENTSThenumberofprotonsinthenucleusofanatomisreferredtoastheatomicnumber,orprotonnumber,Z.Thenumberofelectronsinanelectricallyneutralatomisalsoequaltotheatomicnumber,Z.Thetotalmassofanatomisdeterminedverynearlybythetotalnumberofprotonsandneutronsinitsnucleus.Thistotaliscalledthemassnumber,A.Thenumberofneutronsinanatom,theneutronnumber,isgivenbythequantityA-Z.Thetermelementreferstoapuresubstancewithatomsallofasinglekind.Tothechemistthe“kind”ofatomisspecifiedbyitsatomicnumber,sincethisisthepropertythatdeterminesitschemicalbehavior.AtpresentalltheatomsfromZ=1toZ=107areknown;thereare107(112)chemicalelements.Eachchemicalelementhasbeengivenanameandadistinctivesymbol.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)Acompletelistingoftheelementsmaybefoundintable1.Allatomsofagivenelementmusthavethesameatomicnumber,buttheymayhavedifferentmassnumbers.Thedifferentnuclidesofanelementarereferredtocollectivelyasisotopesoftheelement.InSection2-7,wherethediscoveryandcharacterizationofisotopeswasdiscussed,itwaspointedoutthatthereisonetypeofneonatomwithamass22/20asgreatasthepredominantatomicspecies.Actuallythreedifferentnuclidesexist;therearethreeisotopesofneon,Bysymbol,theseare2010Ne,2110Ne,and2210Ne.Thenaturalabundancesofthesenuclidesare90.9,0.3and8.8%,respectively.Sometimesthemassnumbersofisotopesareincorporatedintothenamesofelements,suchasneon-20,carbon-12andoxygen-16.Inaneutralatomthenumberofelectronsmustbeequaltothenumberofprotons,Z.Butifanatomeitherlosesorgainselectrons,itacquiresanetelectriccharge,itbecomesanion.Thespecies2010Ne+and2010Ne2+areions.Thefirstonehastenprotons,tenneutrons,andnineelectrons,thesecond,tenprotons,tenneutrons,andeightelectrons.1.THENONMETALELEMENTSWenotedearlierthatnonmetalsexhibitpropertiesthataregreatlydifferentfromthoseofthemetals.Asarule,thenonmetalsarepoorconductorsofelectricity(graphiticcarbonisanexception)andheat;theyarebrittle,areoftenintenselycolored,andshowanunusuallywiderangeofmeltingandboilingpoints.Theirmolecularstructures,usuallyinvolvingordinarycovalentbonds,varyfromthesimplediatomicmoleculesofH2,Cl2,I2andN2tothegiantmoleculesofdiamond,siliconandboron.Thenonmetalsthataregasesatroomtemperaturearethelow-molecularweightdiatomicmoleculesandthenoblegasesthatexertverysmallintermolecularforces.Asthemolecularweightincreases,weencounteraliquid(Br2)andasolid(I2)whosevaporpressuresalsoindicatesmallintermolecularforces.CertainpropertiesofafewnonmetalsarelistedinTable2.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 SimplediatomicmoleculesarenotformedbytheheaviermembersofGroupsVandVIandatordinaryconditions.Thisisindirectcontrasttothefirstmembersofthesegroups,N2andO2.Thedifferencearisesbecauseofthelowerstabilityofπbondsformedfromporbitalsofthethirdandhighermainenergylevelsasopposedtothesecondmainenergylevel.Thelargeratomicradiiandmoredenseelectroncloudsofelementsofthethirdperiodandhigherdonotallowgoodparalleloverlapofporbitalsnecessaryforastrongπbond.Thisisageneralphenomenon—strongπbondsareformedonlybetweenelementsofthesecondperiod.Thus,elementalnitrogenandoxygenformstablemoleculeswithbothσandπbonds,butothermembersoftheirgroupsformmorestablestructuresbasedonσbondsonlyatordinaryconditions.NotethatGroupVIIelementsformdiatomicmolecules,butπbondsarenotrequiredforsaturationofvalence.

Sulfurexhibitsallotropicforms.Solidsulfurexistsintwocrystallineformsandinanamorphousform.Rhombicsulfurisobtainedbycrystallizationfromasuitablesolution,suchasCS2,anditmeltsat112℃.Monoclinicsulfurisformedbycoolingmeltedsulfuranditmeltsat119℃.BothformsofcrystallinesulfurmeltintoS-gamma,whichiscomposedofS8molecules.TheS8moleculesarepuckeredringsandsurviveheatingtoabout160℃.Above160℃,theS8ringsbreakopen,andsomeofthesefragmentscombinewitheachothertoformahighlyviscousmixtureofirregularlyshapedcoils.Atarangeofhighertemperaturestheliquidsulfurbecomessoviscousthatitwillnotpourfromitscontainer.Thecoloralsochangesfromstrawyellowatsulfur’smeltingpointtoadeepreddishbrownasitbecomesmoreviscous.

Astheboilingpointof444℃isapproached,thelarge-coiledmoleculesofsulfurarepartiallydegradedandtheliquidsulfurdecreasesinviscosity.Ifthehotliquidsulfurisquenchedbypouringitintocoldwater,theamorphousformofsulfurisproduced.Thestructureofamorphoussulfurconsistsoflarge-coiledheliceswitheightsulfuratomstoeachturnofthehelix;theoverallnatureofamorphoussulfurisdescribedasrubberybecauseitstretchesmuchlikeordinaryrubber.Inafewhourstheamorphoussulfurrevertstosmallrhombiccrystalsanditsrubberypropertydisappears.

Sulfur,andimportantrawmaterialinindustrialchemistry,occursasthefreeelement,asSO2involcanicregions,asH2Sinmineralwaters,andinavarietyofsulfideoressuchasironpyritesFeS2,zincblende

ZnS,galenaPbS,andincommonformationsofgypsumCaSO4·2H2O,anhydriteCaSO4,andbarytesBaSO4·2H2O.Sulfur,inoneformoranother,isusedinlargequantitiesformakingsulfuricacidfertilizers,insecticides,andpaper.SulfurintheformofSO2obtainedintheroastingofsulfideoresisrecoveredandconvertedtosulfuricacid,althoughinpreviousyearsmuchofthisSO2wasdiscardedthroughexceptionallytallsmokestacks.Fortunately,itisnoweconomicallyfavorabletorecoverthesegases,thusgreatlyreducingthistypeofatmosphericpollution.Atypicalroastingreactioninvolvesthechange.kk:abandon,getridof,2ZnS+3O2→2ZnO+2SO2Phosphorus,below800℃,consistsoftetratomicmolecules,P4.Itsmolecularstructureprovidesforacovalenceofthree,asmaybeexpectedfromthethreeunpairedpelectronsinitsatomicstructure,andeachatomisattachedtothreeothers.Insteadofastrictlyorthogonalorientation,withthethreebonds90toeachother,thebondanglesareonly60.Thissupposedlystrainedstructureisstabilizedbythemutualinteractionofthefouratoms(eachatomisbondedtotheotherthree),butitischemicallythemostactiveformofphosphorus.Thisformofphosphorus,thewhitemodification,isspontaneouslycombustibleinair.Whenheatedto260℃itchangestoredphosphorus,whosestructureisobscure.Redphosphorusisstableinairbut,likeallformsof

kk:Indefinite,unclearreciprocal

phosphorus,itshouldbehandledcarefullybecauseofitstendencytomigratetotheboneswheningested,resultinginseriousphysiologicaldamage.Elementalcarbonexistsinoneoftwocrystallinestructures-diamondandgraphite.Thediamondstructure,basedontetrahedralbondingofhybridizedsp3

orbitals,isencounteredamongGroupIVelements.Wemayexpectthatasthebondlengthincreases,thehardnessofthediamondtypecrystaldecreases.Althoughthetetrahedralstructurepersistsamongtheelementsinthisgroup-carbon,silicon,germanium,andgraytin-theinteratomicdistancesincreasefrom1.54?forcarbonto2.80?forgraytin.Consequently,thebondstrengthsamongthefourelementsrangekk:administerfromverystrongtoquiteweak.Infact,graytinissosoftthatitexistsintheformofmicrocrystalsormerelyasapowder.TypicaloftheGroupIVdiamond-typecrystallineelements,itisanonconductorandshowsothernonmetallicproperties.2.GROUPSIBANDIIBELEMENTS2.1PhysicalpropertiesofGroupIBandIIBTheseelementshaveagreaterbulkuseasmetalsthanincompounds,andtheirphysicalpropertiesvarywidely.Goldisthemostmalleableandductileofthemetals.Itcanbehammeredintosheetsof0.00001inchinthickness;onegramofthemetalcanbedrawnintoawire1.8mi(mile)inlength.Copperandsilverarealsometalsthataremechanicallyeasytowork.Zincisalittlebrittleatordinarytemperatures,butmayberolledintosheetsatbetween120to150℃;itbecomesbrittleagainabout200℃.Thelow-meltingtemperaturesofzinccontributetothepreparationofzinc-coatediron,galvanizediron;cleanironsheetmaybedippedintovatsofliquidzincinitspreparation.Adifferentprocedureistosprinkleorairblastzincdustontohotironsheetingforazincmeltandthencoating.Cadmiumhasspecificusesbecauseofitslow-meltingtemperatureinanumberofalloys.Cadmiumrodsareusedinnuclearreactorsbecausethemetalisagoodneutronabsorber.Mercuryvaporanditssaltsarepoisonous,thoughthefreemetalmaybetakeninternallyundercertainconditions.Becauseofitsrelativelylowboilingpointandhencevolatilenature,freemercuryshouldneverbeallowedtostandinanopencontainerinthelaboratory.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.Coppersulfateisusedinelectroplating.Fishermendiptheirnetsincoppersulfatesolutiontoinhibitthegrowthoforganismsthatwouldrotthefabric.Paintsspecificallyformulatedforuseonthebottomsofmarinecraftcontaincoppercompoundstoinhibitthegrowthofbarnacles(藤壺)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)hydroxideInsolublecoppercompounds,exceptcoppersulfide,aredissolvedbyammoniumhydroxide.Theformationofthecopper(II)ammoniaionisoftenusedasatestforCu2+becauseofitsdeep,intensebluecolor.Copper(II)ferrocyanide[Cu2Fe(CN)6]isobtainedasareddish-brownprecipitateontheadditionofasolubleferrocyanidetoasolutionofcopper(II)ions.Theformationofthissaltisalsousedasatestforthepresenceofcopper(II)ions.CompoundsofSilverandGoldSilvernitrate,Sometimescalledlunarcaustic(醫(yī)用硝酸銀),isthemostimportantsaltofsilver.Itmeltsreadilyandmaybecastintosticksforuseincauterizingwounds.Thesaltispreparedbydissolvingsilverinnitricacidandevaporatingthesolution.)Copper(II)hexacyanoferrate(II)

3Ag+4HNO3→NO+2H2O+3AgNO3Thesaltisthestartingmaterialformostofthecompoundsofsilver,includingthehalidesusedinphotography.Itisreadilyreducedbyorganicreducingagents,withtheformationofablackdepositoffinelydividedsilver;thisactionisresponsibleforblackspotsleftonthefingersfromthehandlingofthesalt.Indelible(擦不掉的)markinginksandpencilstakeadvantageofthispropertyofsilvernitrate.Thehalidesofsilver,exceptthefluoride,areveryinsolublecompoundsandmaybeprecipitatedbytheadditionofasolutionofsilversalttoasolutioncontainingchloride,bromide,oriodideions.Theadditionofastrongbasetoasolutionofasilversaltprecipitatesbrownsilveroxide(Ag2O).OnemightexpecttheNitricacidnitrogenmonoxidesilvernitratepermanenthydroxideofsilvertoprecipitate,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.Theactionisprobablyduetofreechlorinepresentintheaquaregia.(Nitrogen(III)oxidechloride)3HCl+HNO3→NOCl+Cl2+2H2O2Au+3Cl2→2AuCl3

AuCl3+HCl→HAuCl4(chloroauricacid)CompoundsofZincZincisfairlyhighintheactivityseries.Itreactsreadilywithacidstoproducehydrogenanddisplaceslessactivemetalsfromtheirsalts.Theactionofacidsonimpurezincismuchmorerapidthanonpurezinc,sincebubblesofhydrogengascollectonthesurfaceofpurezincandslowdowntheaction.Ifanothermetalispresentasanimpurity,thehydrogenisliberatedfromthesurfaceofthecontaminatingmetalratherthanfromthezinc.Anelectriccoupletofacilitatetheactionisprobablysetupbetweenthetwometals.Zn+2H+→Zn2++H2Zincoxide(ZnO),themostwidelyusedzinccompounds,isawhitepowderatordinarytemperatures,butchangestoyellowonheating.Whencooled,itagainbecomeswhite.Zincoxideisobtainedbyburningzincinair,byheatingthebasiccarbonate,orbyroastingthesulfide.TheprincipaluseofZnOisasafillerinrubbermanufacture,particularlyinautomobiletires.Asabodyforpaintsithastheadvantageoverwhiteleadofnotdarkeningonexposuretoanatmospherecontaininghydrogensulfide.Itscoveringpower,however,isinferiorto(superiorto)thatofwhitelead.3.GROUPⅢB—ⅧBELEMENTSGroupⅢBincludestheelementsscandium,yttrium,lanthanum,andactinium,andthetworare-earthseriesoffourteenelementseach-thelanthanideandactinideseries.Theprincipalsourceoftheseelementsisthehighgravityriverandbeachsandsbuiltupbyawater-sortingprocessduringlongperiodsofgeologictime.Monazitesand,whichcontainsamixtureofrareearthphosphates,andanyttriumsilicateinaheavysandarenowcommercialsourcesofanumberofthesescarceelements.Separationoftheelementsisadifficultchemicaloperation.Thesolubilitiesoftheircompoundsaresonearlyalikethataseparationbyfractionalcrystallizationislaboriousandtime-consuming.Inrecentyears,ionexchangeresinsinhighcolumnshaveprovedeffective.WhencertainacidsareallowedtoflowdownslowlythroughacolumncontainingaresintowhichionsofGroupⅢBmetalsareadsorbed,ionsaresuccessivelyreleasedfromtheresin.Theresultingsolutionisremovedfromthebottomofthecolumnortowerinbandsorsections.Successivesectionswillcontainspecificionsintheorderofreleasebytheresin.Forexample,lanthanumion(La3+)ismosttightlyheldtotheresinandisthelasttobeextracted,lutetiumion(Lu3+)islesstightlyheldandappearsinoneofthefirstsectionsremoved.Ifthesolutionsarerecycledandtheacidconcentrationscarefullycontrolled,veryeffectiveseparationscanbeaccomplished.Quantitiesofallthelanthanideseries(exceptpromethium,Pm,whichdoesnotexistinnatureasastableisotope)areproducedforthechemicalmarket.Thepredominantgroupoxidationnumberofthelanthanideseriesis+3,butsomeoftheelementsexhibitvariableoxidationstates.Ceriumformscerium(III)andcerium(IV)sulfates,Ce2(SO4)3andCe(SO4)2,whichareemployedincertainoxidation-reductiontitrations.Manyrareearthcompoundsarecoloredandareparamagnetic,presumablyasaresultofunpairedelectronsinthe4forbitals.Allactinideelementshaveunstablenucleiandexhibitradioactivity.Thosewithhigheratomicnumbershavebeenobtainedonlyintraceamounts.Actinium(89Ac),likelanthanum,isaregularGroupⅢBelement.Inchemicalpropertiestheseelementsresemblesilicon,buttheybecomeincreasinglymoremetallicfromtitaniumtohafnium.Thepredominantoxidationstate