Scandium 27116 226129137 2008-07-16T23:08:37Z 70.91.125.117 /* Applications */ {{pp-move-vandalism|small=yes}} {{redirect|Element 21|the golf company|Element 21 (golf company)}} {{Infobox scandium}} '''Scandium''' ({{pronEng|ˈskændiəm}}) is a [[chemical element]] that has the symbol '''Sc''' and [[atomic number]] 21. A silvery white [[metal]] that is always present as compounds, scandium ores occur as rare minerals from [[Scandinavia]] and elsewhere, and it is sometimes considered along with [[yttrium]], and the [[lanthanide]]s and [[actinides]], to be a [[rare earth element]]. == Notable characteristics == Scandium is a [[rare]], hard, silvery, rough very dark [[metal]]lic element that develops a slightly yellowish or pinkish cast when exposed to air. It is not resistant to weathering when pure and is destroyed on prolonged contact with most dilute acids. However, like some other reactive metals, this metal is not attacked by a 1:1 mixture of [[nitric acid]] ([[hydrogen|H]][[nitrogen|N]][[oxygen|O]]<sub>3</sub>) and hydrofluoric acid, [[hydrogen|H]][[fluorine|F]]. The rarity of scandium is not an arbitrary fact. The thermonuclear reactions that produce the elements in this range of [[atomic number]]s tend to produce much greater quantities of elements with an even atomic number. These elements were usually produced by the fusion of lighter elements with [[helium]]-4 nuclei, starting with [[carbon]]-12 (element six). Thus, the common elements in the range of scandium are atomic numbers 18 ([[argon]]), 20 ([[calcium]]), 22 ([[titanium]]), and 24 ([[chromium]]); with elements with odd atomic numbers 19 ([[potassium]]), 21 (scandium), and 23 ([[vanadium]]) being rarely produced, and thus much less common. The production of the odd-numbered elements in this range result from much less common thermonuclear reactions, as is explained elsewhere. == Applications == Since it is not a very common metal, scandium does not have many applications. If it were more common, it might be useful in the making of aircraft and [[spacecraft]] structures, probably alloyed with other metals. It is used in lacrosse sticks; a light yet strong metal is needed for precise accuracy and speed. Backcountry tent manufacturers sometimes use scandium alloys in tent poles. U.S. gunmaker [[Smith & Wesson]] produces a few variations including a large, medium, and small lightweight revolver with a frame composed of scandium alloy and a titanium cylinder.<ref> {{cite web | url = http://www.smith-wesson.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=10001&catalogId=11101&langId=-1&productId=14765&tabselected=tech&isFirearm=Y&parent_category_rn=15704 | title = Small Frame (J) - Model 340PD Revolver | publisher = [[Smith & Wesson]]}}</ref> Approximately 20 kg (as Sc<sub>2</sub>[[oxygen|O]]<sub>3</sub>) of scandium is used annually in the [[United States]] to make high-intensity lights. <ref name="CRC">C.R. Hammond in ''CRC Handbook of Chemistry and Physics'' 85th ed., Section 4; The Elements</ref> [[Scandium iodide]] added to [[mercury-vapor lamp]]s produces an efficient artificial light source that resembles sunlight, and which allows good color-reproduction with [[television|TV]] cameras. About 80 kg of scandium is used in light bulbs globally per year. The [[radioactive isotope]] Sc-46 is used in [[oil refinery|oil refineries]] as a tracing agent. <ref name="CRC"/> The main application of scandium by weight is in aluminium-scandium [[alloy]]s for minor aerospace industry components, and for unusual designs sports equipment (bikes, golf clubs, baseball bats, firearms, etc.) which rely on high performance materials. However, [[titanium]], being much more common, and similar in lightness and strength, is much more widely used, with tons found in some aircraft, especially military ones. When added to aluminium, scandium substantially lowers the rate of recrystallization and associated grain-growth in weld heat-affected zones. Aluminium, being a face-centred-cubic metal, is not particularly subject to the strengthening effects of the decrease in grain diameter. However, the presence of fine dispersions of Al<sub>3</sub>Sc does increase strength by a small measure, much as any other precipitate system in aluminium alloys. It is added to aluminium alloys primarily to control that otherwise excessive grain growth in the heat-affected zone of weldable structural aluminium alloys, which gives two knock-on effects; greater strengthening via finer precipitation of other alloying elements and by reducing the precipitate-free zones that normally exist at the grain boundaries of age-hardening aluminium alloys. The original use of scandium-aluminium alloys was in the nose cones of some USSR submarine-launched ballistic missiles (SLBMs). The strength of the resulting nose cone was enough to enable it to pierce the ice-cap without damage, and so, enabling a missile launch while still submerged under the Arctic ice cap. [[Scandium triflate]] is a catalytic [[Lewis acid]] used in [[organic chemistry]]. == History == [[Dmitri Mendeleev]] used his [[periodic law]], in [[1869]], to predict the existence of, and some properties of, three unknown elements, including one he called ''[[Mendeleev's predicted elements#Ekaboron and scandium|ekaboron]] ''. Lars Fredrick Nilson and his team, apparently unaware of that prediction in the spring of [[1879]], were looking for [[Rare earth element|rare earth]] metals. By using spectral analysis, they [[discovery of the chemical elements|found a new element]] within the minerals [[euxenite]] and [[gadolinite]]. They named it scandium, from the [[Latin]] ''Scandia'' meaning "Scandinavia", and in the process of isolating the scandium, they processed 10 [[kilogram]]s of euxenite, producing about 2.0 [[gram]]s of a very pure [[scandium oxide]] (Sc<sub>2</sub>O<sub>3</sub>). [[Per Teodor Cleve]] of Sweden concluded that scandium corresponded well to the hoped-for ekaboron, and he notified Mendeleev of this in August. Fischer, Brunger, and Grienelaus prepared metallic scandium for the first time in [[1937]], by [[electrolysis]] of a [[eutectic]] melt of [[potassium]], [[lithium]], and [[scandium chloride]]s at a temperature of 700 to 800°[[Celsius|C]]. [[Tungsten]] wires in a pool of liquid [[zinc]] were the [[electrode]]s in a [[graphite]] crucible. The first pound of 99% pure scandium metal was not produced until [[1960]]. == Occurrence == Scandium is distributed sparsely on earth, occurring only as trace quantities in many [[mineral]]s. Rare minerals from Scandinavia and [[Madagascar]], such as [[thortveitite]], [[euxenite]], and [[gadolinite]] are the only known concentrated sources of this element (which is never found as a free metal). It is also found in residues that remain after [[tungsten]] is extracted from [[wolframite]], and from ores after [[uranium]] and [[thorium]] have been extracted. Scandium is more common in the sun and certain [[star]]s than on [[Earth]]. Scandium is only the 50th most common element on earth (35th most abundant in the Earth's [[Crust (geology)|crust]]), but it is the 23rd most common element in the sun. The [[blue]] color of the [[aquamarine]] variety of [[beryl]] is thought to be caused by scandium impurities in it. == Isolation == Thortveitite and kolbeckite are the primary mineral sources of scandium. [[Uranium]]-mill tailings by-products also are an important source. Pure scandium is commercially produced by [[redox|reducing]] [[Scandium(III) fluoride|scandium fluoride]] with metallic [[calcium]]. == Scandium market == World production of scandium is in the order of 2,000 kg per year, generally as a by-product of uranium and nickel-cobalt-copper or [[platinum group]] element mining. Consumption is in the order of 5,000 kg, and typically is consumed in bicycle frames in Sc-Al alloys. The present main source of scandium metal to meet this shortfall is from the military stockpiles of the former Soviet Union (mainly in the country of [[Ukraine]]), which were extracted from uranium tailings. There is no primary production in the Americas, Europe, or Australia, although gigantic scandium deposits are associated with uranium, [[nickel]]-[[copper]]-[[cobalt]] [[laterite]] deposits and associated with ultramafic rocks worldwide. Scandium can also be extracted from tantalum residues, tungsten processing wastes, tin slags and a variety of other such industrial waste streams, and it is sometimes recovered from rare earth ores, particularly the rare earth oxide deposits of Bayan Obo, China. The strength and commerciality of the scandium market is yet to be demonstrated as it is a specialty metal and a single producer could corner the supply with minimal tonnage production. The price in 2006 of 99.0% scandium oxide is of order of US$700 per kilogram <ref> [http://minerals.usgs.gov/minerals/pubs/commodity/scandium/scandmcs07.pdf Scandium] United States Geological Society, 2006 </ref> == Compounds == The most common [[oxidation state]] of scandium in is +3. Scandium chemically resembles yttrium and the rare earth metals more than it resembles [[aluminium]] or [[titanium]]. Thus scandium is sometimes seen as the scandium oxide, Sc<sub>2</sub>O<sub>3</sub>, and as scandium chloride, ScCl<sub>3</sub>. == Isotopes == {{main|isotopes of scandium}} Naturally occurring scandium is composed of 1 stable [[isotope]] <sup>45</sup>Sc. 13 [[radioisotope]]s have been characterized with the most stable being <sup>46</sup>Sc with a [[half-life]] of 83.8 days, <sup>47</sup>Sc with a half-life of 3.35 days, and <sup>48</sup>Sc with a half-life of 43.7 hours. All of the remaining [[radioactive]] isotopes have half lives that are less than 4 hours, and the majority of these have half-lives that are less than 2 minutes. This element also has 5 [[meta state]]s with the most stable being <sup>44m</sup>Sc (t<sub>½</sub> 58.6 h). The isotopes of scandium range in [[atomic weight]] from 40 [[atomic mass unit|u]] (<sup>40</sup>Sc) to 54 u (<sup>54</sup>Sc). The primary [[decay mode]] at masses lower than the only stable isotope, <sup>45</sup>Sc, is [[electron capture]], and the primary mode at masses above it is [[beta emission]]. The primary [[decay product]]s at atomic weights below <sup>45</sup>Sc are [[calcium]] isotopes and the primary products from higher atomic weights are [[titanium]] isotopes. == See also == * * ==References== *[http://periodic.lanl.gov/elements/21.html Los Alamos National Laboratory &ndash; Scandium] <references/> == External links == {{Commons|Scandium}} {{wiktionary|scandium}} *[http://www.webelements.com/webelements/elements/text/Sc/index.html WebElements.com &ndash; Scandium] {{clear}} {{compact periodic table}} [[Category:Chemical elements]] [[Category:Transition metals]] [[Category:Scandium|*]] [[Category:Scandium compounds|Scandium compounds]] [[Category:Scandium minerals|Scandium minerals]] [[Category:Scandium compounds|compounds]] [[af:Skandium]] [[ar:سكانديوم]] [[ast:Escandiu]] [[bn:স্ক্যানডিয়াম]] [[be:Скандый]] [[bs:Skandijum]] [[bg:Скандий]] [[ca:Escandi]] [[cs:Skandium]] [[co:Scandiu]] [[da:Scandium]] [[de:Scandium]] [[et:Skandium]] [[el:Σκάνδιο]] [[es:Escandio]] [[eo:Skandio]] [[eu:Eskandio]] [[fa:اسکاندیم]] [[fr:Scandium]] [[fur:Scandi]] [[gv:Scandjum]] [[gl:Escandio]] [[ko:스칸듐]] [[hy:Սկանդիում]] [[hi:स्काण्डियम]] [[hr:Skandij]] [[io:Skandio]] [[id:Skandium]] [[is:Skandín]] [[it:Scandio]] [[he:סקנדיום]] [[jv:Skandium]] [[kn:ಸ್ಕ್ಯಾಂಡಿಯಮ್]] [[sw:Skandi]] [[ht:Skandyòm]] [[ku:Skandiyûm]] [[la:Scandium]] [[lv:Skandijs]] [[lb:Scandium]] [[lt:Skandis]] [[jbo:jinmrskandi]] [[hu:Szkandium]] [[mk:Скандиум]] [[ml:സ്കാന്‍ഡിയം]] [[mr:स्कॅन्डियम]] [[nl:Scandium]] [[ja:スカンジウム]] [[no:Scandium]] [[nn:Scandium]] [[oc:Escandi]] [[uz:Skandiy]] [[pl:Skand]] [[pt:Escândio]] [[qu:Iskandyu]] [[ru:Скандий]] [[scn:Scandiu]] [[simple:Scandium]] [[sk:Skandium]] [[sl:Skandij]] [[sr:Скандијум]] [[sh:Skandij]] [[fi:Skandium]] [[sv:Skandium]] [[th:สแคนเดียม]] [[vi:Scandi]] [[tr:Skandiyum]] [[uk:Скандій]] [[zh:钪]]