Laval University
From the SelectedWorks of Fathi Habashi
2015
Metals through ages Fathi Habashi
Available at: https://works.bepress.com/fathi_habashi/163/ Metals Through the Ages. Their Discovery and Isolation
Fathi Habashi Laval University, Quebec City Canada
Metall volume 69 2015
Metall-RubMetall historikrisch
produced beautiful artefacts. As early as Metals Through the Ages. the Fifth Dynasty (2690-2420 BC) the ancient Egyptians documented primitive metallurgical operations on wall paintings Their Discovery and Isolation which show blow-pipes in use with small furnaces and later they depict the use of bellows so that a high temperature can be Habashi, F. (1) Part 1 reached when air is blown in the fire by these means (Figure 1). They were able to Seven metals were known to the ancient people: gold, silver, copper, iron, mercury, hammer gold so that foils can be produced lead, and tin. In the Middle Ages the metalloids arsenic, antimony, and bismuth and used for gilding wood and stones. were added. Platinum was later brought from South America then zinc and boron became known from the East. It was only in the eighteenth century that mineralo- Silver and lead gists, travellers, and analysts supplied mineral specimens from different localities to laboratories where they were analyzed and this resulted in the discovery of ura- Silver occurs as native metal or an alloy with nium, zirconium, yttrium, beryllium, and chromium. In the nineteenth century the gold called electrum. The mines of Laurion bulk of metals became known mainly due to Swedish chemists. In the twentieth century the very rare remaining metals: rhenium and hafnium were discovered and isolated. In the meantime metals that do not occur in nature or occur only in infini- tesimal quantities: protactinium, technetium, francium, promethium, and the trans- uranium metals became known and were isolated. Reasons behind the discovery are analyzed.
eople had inhabited the Earth for temperature can be attained by burning hundreds of thousands of years carbonaceous material. before they began to use metals. W Some of these metals have low melting This was the Stone Age in which points, for example, lead and tin, while Pthe only tools available were pieces of wood, mercury is already liquid at room tem- bone, flint, or sea shells. The ancient people perature, thus they are easy to recover. used only those metals that were available Impurities in a metal lower the melting without mining or chemical treatment, for point considerably; for example, iron Fig. 2: Ancient Greek coin example, pieces of native gold, silver, and containing 4% carbon already melts copper, and rare pieces of meteoric iron. at 1100 °C while the pure metal melts near Athens in ancient Greece supplied These were too small in quantity to be of at 1540 °C. Metals used by the ancient most of the silver which was mainly used to any consequence. people were seldom pure. Brass, an alloy mint coins (Figure 2). Lead ores also con- of copper with zinc, was prepared by tain silver and they were sometimes treated The seven metals of antiquity smelting a copper ore and another ore for silver. Lead was widely used in Roman known as calamine. times mainly in making pipes (Figure 3). The ancient people knew only seven met- als: gold, silver, copper, iron, mercury, lead, Gold and tin. There are reasons for the early availability of these metals: As civilization progressed, gold became W Some of these metals occur in the native an important metal in Egypt. The phar- state, for example gold and silver. aohs sent expeditions of ten of thousands W Oxides of copper, iron, tin, and lead of slaves and soldiers to mine gold in the are readily reduced below 800 °C. Such Eastern Desert. They cast the metal and
Fig. 3: Typical Roman street with lead pipe
Copper and tin
Metallic copper was produced by the reduction of its oxide ores in primitive furnaces. Sinai in Egypt and Cyprus were Fig. 1: Ancient Egyptian wall paintings showing furnaces, manually operated bellows, the main producers. This is believed to melting, and casting of gold be the first metal produced from oxides
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gold; neither of the acids alone has any dis- solving action on gold. Nothing worthwhile in the field of metallurgy took place during the dark ages of magic, superstition, and alchemy except that many acids and salts were prepared, described, and used for a variety of purposes.
Fig. 4: An ancient copper ingot [British Museum] by reduction around 4000 BC. An ancient copper ingot is shown in Figure 4. This was, however, slowly superseded by bronze – a copper alloy containing about Fig. 6: Iron Pillar of Delhi [fourth century 10% tin, easy to melt and to cast. Bronze AD] was either produced by mixing tin pro- duced from its oxide by reduction, with (Figure 7). Gold leaf adheres firmly on the metallic copper, or by reducing a mixture shiny amalgamated copper surface. of copper ore with a tin ore; this period of Fig. 8: An alchemist at work civilization became known as the Bronze Age. A Roman tin ingot is shown in Fig- The flow of knowledge from the East ure 5. to the West
The art of making Toledo swords, famous for 200 years thrived under the Arabs in the eighth century A D. There was cultur- al contact between the Arabs in Damas- cus and the Indians, who excelled in iron making. It was only with the translation of Fig. 5: Roman tin ingot Arabic texts into Latin, and henceforth the [Royal Museum in Truro, Cornwall] flow of alchemical knowledge to Europe in the tenth century, and the appearance of Iron the Renaissance in Italy few centuries later, Fig. 7: A once gilded bronze statue of Mar- that the art of metal extraction started to Iron became known much later than cop- cus Aurelius in Rome take shape. per although iron ores are more abundant than copper ores, having colorful miner- The age of alchemy New metal discoveries als, and almost as easy to smelt. This may be due to the fact that copper can be shaped When an alchemist (Figure 8) dipped a piece In the thirteenth and fourteenth centuries by cold-hammering, whereas iron must be of iron into a solution of copper vitriol, i.e., three new metalloids: arsenic, antimony, hammered hot. The Iron Age began around copper sulfate, the iron was immediately and bismuth became known in Europe in 2000 BC and most probably the Hittites in covered by a layer of metallic copper. This the elemental state and were described by Asia Minor were skilled in this technology. apparent transmutation of iron into cop- Not many iron objects resisted corrosion per led the alchemists to be occupied with through time except perhaps the Iron Pil- the transmutation of base metals into gold. lar of Delhi which was made in the fourth Gold, the most noble of all metals was insol- century AD (Figure 6). uble in all acids or alkalies known at that time. The Arab alchemists of the eighth and Mercury ninth centuries, e.g., the Jabir Ibn Hayyan (720-813 AD) thought they could change Mercury was recovered by heating cinna- iron into gold, a process which became bar ore which occurred in abundance in known as the transmutation of metals. He Spain and north of Italy. It was used as a discovered aqua regia, i.e., royal water is a Fig. 9 and 10: Albertus Magnus (1193-1280) (left) and Georgius Agricola (1494- 1555) sticking medium to gild copper statues mixture of HCI and HNO3 that dissolves
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the German monk Albertus Magnus (1193- 1280) (Figure 9) and others.
Mining and metallurgical literature
In the sixteenth century two important books on metallurgy appeared. The first “De La Pirotechnia” appeared in 1540; its author Vannoccio Biringuccio (1480-1538) was working in the Armoury of Siena in Italy, and had traveled widely through Ger- many and Italy. The book, written in Italian, was concerned with ores, assaying, smelt- ing, separating gold from silver, making of alloys, melting, casting, and fireworks. The Fig. 11: Antonio de Ulloa (1716-1795) second book “De Re Metallica” appeared in 1556; a year after the death of its author, attention to this metal when he visited Georgius Agricola (1494- 1555) (Figure 10) this region. The Spaniards unable to melt a medical doctor from Saxony who traveled these particles, they called them platina a widely in the mining districts in this area. diminutive of silver. It took nearly a cen- The title means “Of things Metallic”; it was tury to identify and isolate the components the reference book on mining and metal- of platina: lurgy for at least two centuries. W 1750: Brownrigg and Watson, platinum Fig. 13: Chinese method for producing zinc Fire Assaying W 1803: Tennant, osmium W 1803: Tennant and Des Costils. ble (Figure 12). By 1374, the Hindus had Control of the purity of gold and silver, iridium recognized that zinc was a new metal, and and the prevention of counterfeiting of W 1803: Wollaston, rhodium and a limited amount of commercial zinc pro- coins was always of primary importance palladium duction was underway. to the administrators of the early com- W 1844 : Klaus, ruthenium From India, zinc manufacture moved to munities. It is not surprising, therefore, China where it developed as an industry to that methods for analyzing gold and silver Metals from the east supply the needs of brass manufacture (Fig- were developed. The earliest known pro- ure 13). The Chinese apparently learned cedure which is still in use today, is known The production of metallic zinc was about zinc production sometime around as the fire assaying was documented by described in a Hindu book written around 1600 AD., and from China zinc production Lazarus Ercker (1530-1594). In summary 1200 AD. The new “tin-like” metal was became known in Europe about a century the material is melted with fluxes, litharge made by indirectly heating calamine with and half later. The Chinese also prepared (PbO), and a reducing agent such as flour. organic matter in a covered crucible fitted another alloy which looked like silver but The fluxes contained such ingredients as with a condenser. Zinc vapor was evolved did not contain silver; instead, it contained silica glass, salt, and borax. The gold and and the vapor was air cooled in the con- copper. They called it pai-thung, i.e., white silver are collected in the lead formed by denser located below the refractory cruci- copper. It was imported to Europe in small the reduction of litharge. The lead is then quantities in the early 1700s. Much later, it removed as oxide under oxidizing condi- was found out that this alloy contained a tions in another step known as “cupella- new metal that was called nickel. tion” by absorption in the material of the cupel, and there remains a bead of gold and Metals of the eighteenth century silver, to be weighed. The same principle was applied on large scale for the recovery In the eighteenth century, mineralogists, of precious metals from lead ores. travellers, and analysts played an impor- tant role in the discovery of new metals. Platina from South America Mineral specimens from different localities were continuously supplied to laboratories For centuries the American Indians in where they were analyzed. It was a hobby Ecuador in South America collected the of monarchs and wealthy people to collect silver-like metallic particles found near minerals (Figure 14). This activity resulted the river bed mixed then with gold to make in the discovery of cobalt, nickel, manga- jewellery. They were unable to melt these nese, molybdenum, chromium, tellurium, particles. After the Spanish Conquest, it and uranium (Table 1). Famous analyst of was the Spanish naval officer Antonio de Fig. 12: Schematic representation of the this period was Martin Heinrich Klaproth Ulloa (1716-1795) (Figure 11) who brought Indian method for producing zinc (1743-1817) (Figure 15) who discovered
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Year Metal Discoverer Remarks 1735 Cobalt Brandt Discovered in Sweden 1741 Platinum Wood Metal from South America 1745 Boron Bergman Metal from the East. Isolated in 1808 by Gay-Luss- ac, Thénard, and Davy 1746 Zinc Marggraff Metal from the East 1751 Nickel Cronstedt Discovered in Sweden 1753 Bismuth Geoffrey Metalloid of the alchemists 1774 Manganese Ghan Discovered in Sweden 1781 Molybdenum Hjelm Discovered in Sweden Fig. 14: Emperor Franz I (1708-1765) of 1782 Tellurium Müller von Isolated by Müller von Reichenstein but not named. Austria studies minerals at the Museum of Reichen- Named in 1798 by Klaproth Natural History in Vienna stein 1783 Tungsten Elhujar Discovered in Spain brothers 1789 Uranium Klaproth Klaproth believed that he prepared uranium metal when he reduced U308 with carbon. In fact he
obtained only a lower oxide (UO2). The metal was
isolated by Peligot in 1841 by the reduction of UCl4 with potassium 1789 Zirconium Klaproth Isolated by Berzelius in 1824 by the reduction of the fluoride with sodium 1791 Titanium Gregor Isolated by Berzelius in 1824 (impure metal), Nilson and Pettersson in 1887 (95 % pure), and by Hunter in 1910 (99.9 % pure). 1794 Yttrium Gadolin Discovered in Sweden 1797 Beryllium Vauquelin Isolated by Wöhler and Bussy in 1828 by the reduc- tion of the fluoride with sodium. 1797 Chromium Vauquelin Isolated by Wöhler in 1859 by reducing molten chromium chloride with zinc
Fig. 15: Martin Heinrich Klaproth Tab. 1: Metals discovered in the eighteenth century (1743-1817) an oxidizing or reducing flame, the min- uranium. Beside the blowpipe which was eral samples were fused and from the color a useful analytical tool for chemists, new and appearance of the fused material it was reagents were discovered which were use- possible to draw conclusions regarding its ful in isolating new metals. Also, the fall composition. This useful tool was aban- of the phlogiston theory contributed to the doned only after the invention of spectral better understanding of the smelting proc- analysis in the middle of the nineteenth ess the main metallurgical operation. century.
Blowpipe Discovery of hydrogen
The blowpipe (Figure 16) was so essential Hydrogen discovered by Henry Cavend- for chemical analysis in the eighteenth cen- ish (1731-1810) in 1766 was responsible tury. With its help the qualitative composi- for the isolation of pure metallic tung- tion of most minerals was ascertained and sten by the Swedish chemist Jons Jakob the metals were discovered. The blowpipe Berzelius (1779-1848) (Figure 17) around is essentially a narrow tube with which air 1783. Although hydrogen is a more pow- Fig. 17: Jons Jakob Berzelius (1779-1848) can be blown into the flame. By mixing erful reducing agent than hot carbon, yet discovered cerium, selenium, and thorium suitable fluxes with the sample and using it failed to liberate the alkali metals, the alkaline earth metals, and aluminum from 1774 was used to convert oxides to chlorides their oxides. from which metals could be obtained by reduction when the oxides resisted reduc- Discovery of chlorine tion to metals. For example, niobium, zir- conium, vanadium were first prepared by Chlorine discovered by the Swedish chem- reduction of chlorides when it was not pos- Fig. 16: The blowpipe ist Karl Wilhelm Scheele (1742-1786) in sible to reduce the oxides.
METALL | 65.69. Jahrgang | 6/20117-8/2015 295
MetalsThrough the Ages, TheirDiscovery and lsolation Pat2
Habash.F (ll Flg,l9r BobertBunsen {1811 -1899) Sevenmelals were known lo lhe ancientpeople: gold, silver, copper, iron, morcury, lead,and tin. In the MiddleAgos lho motalloidsarsonic, anlimony, and bismutft ratories(Figure 20). This burnerpermitt€d wereadded. Plalinum was later brought from South Amedca lhen zinc and b0r0n highertemperaiure to be achievedin the bocsmgknown lrom lhe East. lt wasonly in theeighteenth century lhat mineralo- laboratorywhen conducting a test.Before giab,travellers, and analysls supplled mlneral speclmens ftom dlfierenl locallties this burnerthe flame ofa candleor from to laboratodeswhere they lvere analyzed and this resulted inlhe discovery of ura- alcoholwasused.TheBunsenburnerflame nium,zirconlum, yttrlun, berylllum, and chJomium, Inlhe nineteenthcentury he permittedperfonning the flametests (Fig- bulk 0f metalsbecame known mainly due io Swodishchomists, In tie tvJontielh ure2l) andlatcr sp€ctroscopic anallsis. cenlurylheveryrare remaining melalsi ftenium afld hafnium were discovercd and lsolated.Inlhe meanlimo molals thatd0 notoccur in nalurcor occuronly in infini- tasimalquanlilios: piolacllnlum, lechnellum, tranciurn, promelhlum, and lhe lrans- uranlummolals bocamo known and woao isolatod. Roa8ons bohind thg discovgry aroanalyz6d,
Melalsol lhe nineteolhcontuly waspot.$iunmetal,which beingstrongly reactive,bumed in air. ln the sam€way, ln the l9th centurytheb{lkofmetalswere heelectrolyzed soda asb and demonstrated discovered(Table 2). This wasa resultof thatsodiummetalcan be liberated. lhe discoveryof electriccuaent and thc The work of Davy and oth€rsopened an dev€lopmentin analyticalchemhtry and entirelynew area in metallurgy,thouSh the fdctwas nol recognizedat that ti e. The' intensediificulties to b€ overcomewhen Thedlscovery ol elocltlccurront removihgthe oxygeni-rcm $rch oxidesas thoseof potassnrn,sodirm, brriuh, cal Flg.20iBunsen bumer At thc very beginni.g of the century,tbe cium, ind m.gnesiumclerrly suggested Italian scientistAle$andro Volta 1U45 that the ilkaline metils themselvesmight Thcdlscovcry ol th6speclroscope 1827)discovered electric current and this be usedto exlractthc oxygenfron other provedto bea v€ry inportant toolfor m€t' oxidesthat pfove difficult to spln.Ahmi In thesecoDd hallof the nineteenth century allurgisls.Th€ newly invent€dVolta cell num oxidewas so ieshtantto allhedrods thespectroscope {Figure 22)was invented wasfor the first time usedby the British ofdecompositionthat it wasconsidered at by the Gcrmanchemist Bunsen and the chemistHumphry Davy (1778-1829)(Iig- onetim€ to bean elem€nt,ltwds lhe Dan- physichtKircbhoflin 18s9.Thh ledto the ure l8) !o discove.new metals.Hejoined ish s.ientistChristian Oersted (1777 l85l) discoveryof ibur newmetals in theperiod a largenumber ofth€se cells in seri€s,and who in 1852react€d aluminuft chloride 1850l8s3,namelycesiuh,rubidium,thal thus was able to get . largecurrent. He with potasium amalg.n from which lium, and indium.'lhe spsctroscopegrad- decomposedsolid polashjust moistened minutepa.ticles of aluminu ually displdcedthe blowpipein chemical to conductcu(ent; he noticedthat some ered by distilling off the mercury.The analysis.AD exampleof emissioDspectra thing burnedbrightly at th€cathode.That methodwaslaterapplied to otherchlo.ides is sho{n in Figure23.
Flamelesls
It wasRobert Bunren (1811-1899) (Iigure 19)at the Unive6ity of HeideLberg,who avedthe way for the greatdiscoveries in the niDeteenthcenturywith bis invention Fig.'18: Davy using Volta cells to l$lale so- of th€blrner in 1852that caties his name Fig.21: Examples ofcolourcd llames in diun andoolasslum andis foundtoday in nost chemicallabo llametesls 1801 holatedby Blomstrandjn 1864by reduc' tion ofNbcl. rvith H. and by Moissanin l90l by carbonreduction of Nb.o. in an
1802 1801 DG.overedin lngland
Discover€din England
1807 Davy Dr\coveredIn FnShnd
1808 Dr\coveledrn FranceandEnshnd Fig.22:A first sp€cfoscope Thenard,Davy Davy Da!v Davv DNI Flg,23: Examples ol emission speclra: caF l8l4 lsolatedbv HrlleblJnd aDdNorlon rn 1895 clum,stontium, and barlum l8l7 LithiuDl lsolatedby D.vy in minuteamounh,but in lure form bv Arfwedson Foundationol thealomic theoly
Dalton(1766 1844)theEnglishteach- 1823 Silicon John erolmaihematicsand physics at NewCol- ta27 legenr Manchestershowed in hisbook New 1828 Systcmof ChemicalPhilosophy published 1830 koiatedby Roscoein 1869by H, reduction atomictheorycanbeused ofVCl: Prepared by Mardenand Rich in in 18l0howhis theliwswhich governchemical I927Jpurity 99.9%lby reduction ofthe to explain
1839 t84l lhe discov€ryoftfte Perlodlc Syslom
1844 In 1869,the Rusian che'nist Dimitry (1834- (Figur€ 1860 IvaDovitchMendeleev 1907) 24).rrangedtbe elementswith jn€reasing l86l atomicw€ightand discovered the Periodic Systemleaving gaps in lhis Tablefor ele Drcovcrcd !r EnulinJ tuentsnot yet discovered,and wasable to l86l predict tbeirproperties(Figure 25). This predictionhelped the ch€mists at thattime t875 to searchfor theseelements. within two 1878 decadesthe thfee metalsgallium, scan- t879 diuh, andgennanium were discov€red. Thegreat similarity ir thechem ical prop' ertiesofthe ra.e earlhsmade theirisolation a difficult taskand th€success in separar 1880 ing themcontributed to theknowledge of a 1885 dozennew metals during this p€riod.
1886
1896 1898 holatedbyMne. Curieand Debierne in t9t0 Curie lsolat€dby Mme. Curie and Debiernein t9l0 1899 tsolatedb! CE5elin 1902 Fiq.24: omiby lvanovitci MendelEov Tab.2rMehls discovered and isolated in thenineteenti ceriury 0834-1904
E6!a examinedthe passage of electriccurrent in solutionswhich led to the formulationof thelaws of electrochemistry.
Il |iT-TT-TT-TT--r]-T'T'II X-6ysand radioactivity
Flg.25:llrendeleev's Pedodic Table of 1860 in modem In 1895x'rays were discovered byWilheln form.Shaded areas werc prodlctod olemenl!, emply Conrad Roentgen{1845 1923) followed soaceswera unknown by the discoveryol radioactivityi! 1898 by Antoine Henri Becquerei(1852 1908) Melallolhermlcreaclions which wasresponsible lor tbediscovery of lolonium and radium shortlyafterwards Chemistsof the earlynineteenth centurl by Mafie Cufie (1867-1914)(figure 26). usedthe alkali metalsto libefatenretals A rar latef,Andra Debitrnc (1874-1949) from their compounds-- a reactionthat (Figure 27), a .o '$o.kc. with Curiediscov be.ame known as metallothermicrea- eredand isolated actiriuD. tion. The Swedishchemist ldns takob BerzeliN (17791848) isolated zirconiu'n rnd titanium in 1824for the first time Fig,27: Andre Debldne ('l87+1949) by this method.The methodwas used in 1850sby the lrench chemistHeDri Saint- I 1949,berkeliun Clane Deville (1818-1881)vho produced I I950,crlilbrnium the fi|st alominuh on indrstrial scaleby I 1952,eimteinium heatingAlCl, N.Clwith metallicsodiun. I I956,nobeliunl once aluminumbecame available itr large ? quantiti€s,it wasaho usedto liberatemet alsirom theif compounds. Developmenlof radiochemistry Fig.26rPlore Curio(1859-19{16) and llla e Theindustiial producllon ol Curie(1867-19:14) making a me.surcmenl Radiochem isls played an inrporlantrole in aluminun ol a radloactlvesubslance separatingthe individual radioelements, thcifideotificalidr, nnd thcirarrangement A great technologicaladvancc was lhc Melalsol thelwentieth cenlury in series,New mclhodsof deasuremenis inventionolthe dynamoin the 1870ttlul such.sthe CeiSer cou nter a nd theBaDrna made availableelectricity ir bulk which llemcnts discovercdin thc 20th ccntury scintill0tioncounter replaced th€ gold leat encouragedthe expansionof electrolytic arc thosc which arc vcry rdrc or do not el€ctroscope.Radirtions 1.on radioactive copperrefining to supplythe purecopper occurin nrtuie (T.b1e3). Eldnents beyond substanceswere identified rs alpha,beta, neededfor thcelectrical indust.y. Another plutonnun $e.c discordcd it the L.w andgrnmd. As. re$'lt twovery rare ra
X-rayanalysis james chadwick (1891-1974)in Cam- bridgein 1932explained the experim€nts X rdy+ie.trun.nrlysisby HeDryMoseley of Friddric joliot (1900-1958)and Irane Flg,29add 3): Marguofile Perey (1909- (1887'1915)in l9l4 lcd k) lhcdiscovery of Curie (18971957) in P.ris by supposing 1975)(lefl) and Georyes Uftain (1872-19:A) lwonlctalsr halnitrnr rnd rhenium. rliatalpha particleswer€ knocking neutral particlesout of the nuclei of the b€ryl- lium atom and that theseneutral parti Perey(1909-1975) (Iigure 29) liom wbi.b clcsw€re in tur. knockingp.oions out of thc clenrenttrkes its D.De. lt wdsdiscov- the p.ruffin. In this waythe neutronwas ered during the pMilicrtioD of d sdnrPle oiactiniuD227. It is extremelyrarc, vith traceimotrnts lbund in uraniumrnd tho- l{ouironcapture rium ores,where the isotope h0nciuF223 cootinuallyforns ind decays. In 1934,Enrico Fermi ( 1901- 1954) in Rome discoveredthat neutronsmay be captured Thodiscovory ot luietium Flg.3land 3,2: Dirk Coster (1883-1350) by atomsaod thatthe fiequencyofcapture (10fi)and Georg von Hevesy (1885-1366) increaseswhen they a.e sloweddown by LutetiuD,elcntenLTl,wasdiscovered spec passingthem through a hydrogenlich boscopicxllyin 1907by the lrench chcn]. material such as paraffin or water.He istCeorgesUrbain (1872 1938) (Figtrre30) 1\'asthus able to produceatoms ofhigher who Damedit atterLuliathc Romanndme atomicweights than thosebombarded. For oftheplace where Pa fis wasfounded. lt Nas example,on bonbardingcobalt with n€u' identifiedby Bob. asa rareearth andlot tro.s hewas able to producenickel.When, asa memberof GrouPlV howeverhe and his coworkers bombarded uranium with neukons, they obtained ouartuntheory more than one radioactiveproduct. lol lowingthe same line of thoughtas in their Thequantum theoryryMax Plan.k(1858 previousexperiments they sugg€stedthat 1947)is basedon theprinciple thatenergy oneof thesepioducts was formed by neu like matter js aLsocomposed of nrinute Fig.33:lda Noddack lbom Tackel (1836- tron capture,i.e,, that it wasa trans-urani- quantitiescalled quanta, i.e., energy is 1978)and Waller Noddack (1&9&1962) un elementor elementnumber 93. Iermi cles,the nuclearleactions that take pla€e University of California, Berkeley,where involvethe emission ofan electron,a pro it wasfirst operatedin 1932.Byits means ton, or a heliumnucleus and the massof technetiumand the tlans uraniummetais the bombardedatom suffers little change. when, however neutronsare used,new typesof nuclearreaction should take place lechnetiun that are completelydifferent from those In i937the Italianphysicists Enilio Segrd
Discoveryof uraniunlissiorl
Fermit experimentswere repeatedby n9.34:Eka-fteniun accordlng toF.mi,l9:14 Otto Hahn (1879-1968)andhis coworkers in Derlin.Th€y confirmed Fermi's conclu' putthe newelementunder.henium in the sionsand publisheda seriesotpapers on PeriodicTable and calledit eka{henium extensiveradiochemical s€paratio.s of (Figure34). the so-calledtrans-uraniutu €lements. Iermis papernatumllyattractedthe atten- The results,however, b€came so contra tion of Ida Noddackthe discovererof rhe dictory that after fiv€ yearsof intensive Flg.38.nd37: Emlllo Sogrd (1906-1S) nium becaos€i! d€altwith anotherelenent researchand €xlensivepublication the (b$ andGlenn T,Soaboru (tSlz-lSS) in the manganes€gfoup. Soon afterward, conceptof trans-uranium€lements had sh€published a paperwhich showedthat to be abandoned.Hahn then announced (190s1989)(Figure36)andhirco'worker Iermit experimentalevidence was incom in January1939 the definiteformation of C. Perrierannounced the d€tectionofthe plete.She was critical of his conclusions, barium during the bombardm€ntofura- elementwith atomicnumber 43 in tr.ce sayingthatall elementsin thePeriodic Sys- nium and start€dspeculating about the amountsin a molybdenumtarget which temwould haveto beeliminat€dbefor€one mechanismofits formation.Hahn could hasbeen bombarded in the cyclotronfor couldclaimto havefound a trans-uranium not acceptthe new ideathatthe uranium severalmonths with a strong deuteron €lement.She went further and suggest€d atom was split into rwo fragments.It beam.They called this newelement tech- thatr"when heavynuclei are bombarded was Lise Meihrer ir Swedenwho finally netiumderivingth€ name from th€Greek by neutrons,it wouldbe reasonable to con explainedthe resultsof the work as fis' ceivethat they break down into numeF sion,a f-ewmotrthslft€rshe was forced to ouslarge fragments which are hotoPesof leaveG€rmany in 1939. Trans-uranlummolals knownelements but arenot n€ighbounof the bombardedelemenls fTranslation by Cyclotron After elucidatingthe electronicstructure of the trans-ufanium (Table 5) which Her argumentwasas follows:wh€n atoms Th€ cyclot.onwas invented by ErnestO. res€mbledthat ofthe Ianthanides, Seaborg ar€bombafded by protonsor alphaparti- Lawrence(1901'1958) (Figure 35) of the (1912-199e)(Figu.e 37) proposed a second le.ies of inner transilio! metalssimil.r to the lanthanidesthat b€cameknown "actinides". as He changedthe Periodic Tableof l94s (ligure 38).Thus, uranium was r€movedfrom Group VI to become a memberofthis new group as shownin Figure39.
Promolhlum
The existenceof a rare ea.th element betweenneodyniun and samariumwas predicted by B.unauer This was con- tuned in l9l4 by Henry Moseleywho, havingmeasured the atomicnunbe.s of allthe elementsthenknown, found there was no elementlvith atomicnumber 5r. This elementwas discove.edby Gl€nd' enin, Marinsky.and Coryell in 1945at Oak Ridge National Labor.tory in ura- "pro' nium fissionproducts ard named methium , Promethiun doesnot occur Fig.35: Emesl 0. Law€nce(1$1-1s8) lriglli] standingnsxl i0 lh6 cldolron
'ET;;TMI;I*I;I;[;T'T*T *I;EN
Fl0,38:Ihe PedodicTable ol19{5 Flg.3s PedodicTa!16 aflor 19{li incorDomlinglho acfnldos
Tab.5:Eloctlr o ltuctnb 0l t|m3-onnlum
tik QnAbec,Qu{b.c City 2006r dlstribni.d bJ.LNal Univ{sity Boolctor.. vww.zon.. - M.E.Weeks. Dnco. of th. Elements,6lh .dition,lournal ofchimlc.l Edocation, E*-
(1)Fathi HabashLDepartnent ol MininS, Metallutgi.oL, oM Materiak Engi neering,Ldrol Ufive5ity, QuabecCitr,
Fl0.{} Summaryofft8 dl8oovoryol mohls Summaly
Figufe44 Sivesa summaryofthe dis€ov- eryofmetals. Metalloidsknown durinSthe AgeofAlch€my, platina from SouthAmer- ica,and metals from theEast are combined in one period:Medieval m€lals. The Ii8- u.eshows lhatthe metalsdiscovered inthe 19th c€nturybecause of tbe discoveryof thesp€ctroscope and the PeriodicTable: I Specros.ope:cesium, rubidium, thal'
I PeriodicTable:gallium, scandium, ard
ln the 20th centlrry it was the discov- ery of X-ray analysis,the new tools in radiochemistry,and the cyclotron that led to the discoveryof the lastremainitrg
r X rayanalysis: hafniun andrhenium I N€wtools in radiochemist.y:francium
I Cyclotron:technetium and the trans-
Suggostodrcadln0s
- L. Ancheson,A HistoryofMetals, 2 volunes, Inte$cience. New York 1960 - F. Hrbashi,edno!, A Hntory of.r,telallulsy, MetallurE'eErr.ctive Queba.,Quabec Citi, l99a:d,siribut.d by La€l UnLve6ityBook' - F. H.bashi,Readinss in Hhtolical Metal- lurs. Volumer - Chme'nq Technoloayin lrir;dre Metallursy.Mdt;llursr lxliac
rtEr^, t I Aa laft^ nd l ltDilE S'13 :