AskDefine | Define lithium

Dictionary Definition

lithium n : a soft silver-white univalent element of the alkali metal group; the lightest metal known; occurs in several minerals [syn: Li, atomic number 3]

User Contributed Dictionary

see Lithium

English

Pronunciation

  • /ˈlɪθiəm/

Etymology

From sc=Grek.

Noun

  1. The simplest alkali metal, the lightest solid element, and the third lightest chemical element (symbol Li) with an atomic number of 3.
  2. Lithium carbonate or other preparations of lithium metal used to treat manic depression and bipolar disorders.
chemical element
  • Afrikaans: lithium
  • Albanian: litium
  • Arabic: ليثيوم
  • Armenian: լիթիում
  • Basque: litioa
  • Belarusian: лiтый
  • Bosnian: litij, litijum
  • Breton: litiom
  • Bulgarian: литий
  • Catalan: liti
  • Chinese: 鋰 / 锂
  • Cornish: lythyum
  • Croatian: litij
  • Czech: lithium
  • Danish: lithium
  • Dutch: lithium
  • Esperanto: litio
  • Estonian: liitium
  • Faroese: lithium
  • Finnish: litium
  • French: lithium
  • Friulian:
  • Galician: litio
  • Georgian: ლითიუმი
  • German: Lithium
  • Greek, Modern: λίθιο
  • Hebrew: ליתיום
  • Hungarian: lítium
  • Icelandic: litín
  • Interlingua: lithium
  • Irish: litiam
  • Italian: litio
  • Japanese: リチウム
  • Kashmiri: (lët)
  • Kazakh: литий
  • Korean: 리튬
  • Latin: lithium
  • Latvian: litijs
  • Lithuanian: litis
  • Luxembourgish: lithium
  • Macedonian: литиум
  • Malay: litium
  • Maltese: litju
  • Manx: litçhey
  • Mongolian: лити
  • Norwegian: litium
  • Polish: lit
  • Portuguese: lítio
  • Romanian: litiu
  • Russian: литий
  • Scottish Gaelic: litiam
  • Serbian:
    Cyrillic: литиjум
    Latin: litijum
  • Slovak: litium
  • Slovene: litij
  • Spanish: litio
  • Swedish: litium
  • Tamil: மென்னியம்
  • Thai: ลิเทียม
  • Turkish: lityum
  • Ukrainian: лiтiй
  • Uzbek: литий
  • Vietnamese: lithi, liti
  • Welsh: lithiwm
  • West Frisian: lithium
treatment for mental disorders

References

Czech

Noun

  1. lithium

Extensive Definition

Lithium () is a chemical element with the symbol Li and atomic number 3. It is a soft alkali metal with a silver-white color. Under standard conditions, it is the lightest metal and the least dense solid element. Like all alkali metals, lithium is highly reactive, corroding quickly in moist air to form a black tarnish. For this reason, lithium metal is typically stored under the cover of oil.
According to theory, lithium (mostly 7Li) was one of the few elements synthesized in the Big Bang, although its quantity has vastly decreased. The reasons for its disappearance and the processes by which new lithium is created continue to be important matters of study in astronomy. Lithium is the 33rd most abundant element on Earth, but due to its high reactivity only appears naturally in the form of compounds. Lithium occurs in a number of pegmatitic minerals, but is also commonly obtained from brines and clays; on a commercial scale, lithium metal is isolated electrolytically from a mixture of lithium chloride and potassium chloride.
Trace amounts of lithium are present in the oceans and in some organisms, though the element serves no apparent biological function in humans. Nevertheless, the neurological effect of the lithium ion Li+ makes some lithium salts useful as a class of mood stabilizing drugs. Lithium and its compounds have several other commercial applications, including heat-resistant glass and ceramics, high strength-to-weight alloys used in aircraft, and lithium batteries. Lithium also has important links to nuclear physics: the splitting of lithium atoms was the first man-made form of a nuclear reaction, and lithium deuteride serves as the fusion fuel in staged thermonuclear weapons.

History and etymology

Petalite (lithium aluminium silicate) was first described in 1800 by the Brazilian scientist José Bonifácio de Andrade e Silva, who discovered the mineral in a Swedish iron mine on the island of Utö. However, it was not until 1817 that Johann August Arfwedson, then a trainee in the laboratory of Jöns Jakob Berzelius, discovered the presence of a new element while analyzing petalite ore. The element formed compounds similar to those of sodium and potassium, though its carbonate and hydroxide were less water soluble and had a larger capacity to neutralize acid. Berzelius gave the alkaline material the name "lithos", from the Greek λιθoς (lithos, "stone"), to reflect its discovery in a mineral, as opposed to sodium and potassium which had been discovered in plant tissue; its name would later be standardized as "lithium". Arfwedson later showed that this same element was present in the mineral ores spodumene and lepidolite. In 1818, Christian Gmelin was the first to observe that lithium salts give a bright red color in flame. However, both Arfwedson and Gmelin tried and failed to isolate the element from its salts.
The element was not isolated until 1821, when William Thomas Brande performed electrolysis on lithium oxide, a process which had previously been employed by Sir Humphry Davy to isolate potassium and sodium. Brande also described pure salts of lithium, such as the chloride, and performed an estimate of its atomic weight. In 1855, Robert Bunsen and Augustus Matthiessen produced large quantities of the metal by electrolysis of lithium chloride. Commercial production of lithium metal began in 1923 by the German company Metallgesellschaft AG through the electrolysis of a molten mixture of lithium chloride and potassium chloride.

Properties

Like other alkali metals, lithium has a single valence electron which it will readily lose to form a cation, indicated by the element's low electronegativity. As a result, lithium is easily deformed, highly reactive, and has lower melting and boiling points than most metals. These and many other properties attributable to alkali metals' weakly-held valence electron are most distinguished in lithium, as it possesses the smallest atomic radius and thus the highest electronegativity of the alkali group. In addition, lithium has a diagonal relationship with magnesium, an element of similar atomic and ionic radius. Chemical resemblances between the two metals include the formation of a nitride in N2, the formation of an oxide when burnt in O2, salts with similar solubilities, and thermally-unstable carbonates and nitrides.
Lithium is soft enough to be cut with a knife, though this is more difficult than cutting sodium. The fresh metal has a silvery-white color which only remains untarnished in dry air. Seven radioisotopes have been characterized, the most stable being 8Li with a half-life of 838 ms and 9Li with a half-life of 178.3 ms. All of the remaining radioactive isotopes have half-lives that are shorter than 8.6 ms. The shortest-lived isotope of lithium is 4Li which decays through proton emission and has a half-life of 7.58043x10-23 s.
7Li is one of the primordial elements or, more properly, primordial isotopes, produced in Big Bang nucleosynthesis (a small amount of 6Li is also produced in stars). Lithium isotopes fractionate substantially during a wide variety of natural processes, including mineral formation (chemical precipitation), metabolism, and ion exchange. Lithium ion substitutes for magnesium and iron in octahedral sites in clay minerals, where 6Li is preferred to 7Li, resulting in enrichment of the light isotope in processes of hyperfiltration and rock alteration. The exotic 11Li is known to exhibit a nuclear halo.

Natural occurrence

See also Lithium minerals.
Lithium is widely distributed on Earth and is the 33rd most abundant element;
  • The high non-linearity of lithium niobate also makes a good choice for non-linear optics applications.
  • Lithium deuteride was the fusion fuel of choice in early versions of the hydrogen bomb. When bombarded by neutrons, both 6Li and 7Li produce tritium—this reaction, which was not fully understood when hydrogen bombs were first tested, was responsible for the runaway yield of the Castle Bravo nuclear test. Tritium fuses with deuterium in a fusion reaction that is relatively easy to achieve. Although details remain secret, lithium-6 deuteride still apparently plays a role in modern nuclear weapons, as a fusion material.
  • Metallic lithium and its complex hydrides such as e.g. Li[AlH4] are considered as high energy additives to rocket propellants[3].
  • Lithium peroxide, lithium nitrate, lithium chlorate and lithium perchlorate are used and thought of as oxidizers in both rocket propellants and oxygen candles to supply submarines and space capsules with oxygen.
  • Lithium will be used to produce tritium in magnetically confined nuclear fusion reactors using deuterium and tritium as the fuel. Tritium does not occur naturally and will be produced by surrounding the reacting plasma with a 'blanket' containing lithium where neutrons from the deuterium-tritium reaction in the plasma will react with the lithium to produce more tritium. 6Li + n → 4He + 3H. Various means of doing this will be tested at the ITER reactor being built at Cadarache, France.
  • Lithium is used as a source for alpha particles, or helium nuclei. When 7Li is bombarded by accelerated protons, 8Be is formed, which undergoes spontaneous fission to form two alpha particles. This was the first man-made nuclear reaction, produced by Cockroft and Walton in 1929.
  • Lithium hydroxide (LiOH) is an important compound of lithium obtained from lithium carbonate (Li2CO3). It is a strong base, and when heated with a fat, it produces a lithium soap. Lithium soap has the ability to thicken oils and so is used commercially to manufacture lubricating greases.
  • It is also an efficient and lightweight purifier of air. In confined areas, such as aboard spacecraft and submarines, the concentration of carbon dioxide can approach unhealthy or toxic levels. Lithium hydroxide absorbs the carbon dioxide from the air by reacting with it to form lithium carbonate. Any alkali hydroxide will absorb CO2, but lithium hydroxide is preferred, especially in spacecraft applications, because of the low formula weight conferred by the lithium. Even better materials for this purpose include lithium peroxide (Li2O2) that, in presence of moisture, not only absorb carbon dioxide to form lithium carbonate, but also release oxygen. E.g. 2 Li2O2 + 2 CO2 → 2 Li2CO3 + O2.
  • Lithium metal is used as a reducing agent in some types of methamphetamine production, particularly in illegal amateur “meth labs.”
  • Lithium can be used to make red fireworks
  • A Bose-Einstein Condensate of Lithium was achieved in 1995.

Production

Since the end of World War II, lithium metal production has greatly increased. The metal is separated from other elements in igneous mineral such as those above, and is also extracted from the water of mineral springs.
The metal is produced electrolytically from a mixture of fused lithium and potassium chloride. In 1998 it was about US$ 43 per pound ($95 per kg).
Chile is currently the leading lithium metal producer in the world, with Argentina next. Both countries recover the lithium from brine pools. In the United States lithium is similarly recovered from brine pools in Nevada.
China may emerge as a significant producer of brine-based lithium carbonate around 2010. Potential capacity of up to 45,000 tonnes per year could come on-stream if projects in Qinghai province and Tibet proceed.

Precautions

Lithium metal, due to its alkaline tarnish, is corrosive and requires special handling to avoid skin contact. Breathing lithium dust or lithium compounds (which are often alkaline) can irritate the nose and throat; higher exposure to lithium can cause a build-up of fluid in the lungs, leading to pulmonary edema. The metal itself is usually a handling hazard because of the caustic hydroxide produced when it is in contact with moisture. Lithium should be stored in a non-reactive compound such as naphtha or a hydrocarbon.

Regulation

Some jurisdictions limit the sale of lithium batteries, which are the most readily available source of lithium metal for ordinary consumers. Lithium can be used to reduce pseudoephedrine and ephedrine to methamphetamine in the Birch reduction method, which employs solutions of alkali metals dissolved in anhydrous ammonia. However, the effectiveness of such restrictions in controlling illegal production of methamphetamine remains indeterminate and controversial.
Carriage and shipment of some kinds of lithium batteries may be prohibited aboard certain types of transportation (particularly aircraft), because of the ability of most types of lithium batteries to fully discharge very rapidly when short-circuited, leading to overheating and possible explosion. However, most consumer lithium batteries have thermal overload protection built-in to prevent this type of incident, or their design inherently limits short-circuit currents.

References

See also

lithium in Afrikaans: Litium
lithium in Arabic: ليثيوم
lithium in Asturian: Litiu
lithium in Belarusian: Літый
lithium in Belarusian (Tarashkevitsa): Ліцій
lithium in Bulgarian: Литий
lithium in Bengali: লিথিয়াম
lithium in Bosnian: Litijum
lithium in Catalan: Liti
lithium in Corsican: Litiu
lithium in Czech: Lithium
lithium in Chuvash: Лити
lithium in Welsh: Lithiwm
lithium in Danish: Lithium
lithium in German: Lithium
lithium in Modern Greek (1453-): Λίθιο
lithium in Esperanto: Litio
lithium in Spanish: Litio
lithium in Estonian: Liitium
lithium in Basque: Litio
lithium in Persian: لیتیوم
lithium in Finnish: Litium
lithium in French: Lithium
lithium in Friulian: Liti
lithium in Irish: Litiam
lithium in Galician: Litio
lithium in Manx: Litçhey
lithium in Hebrew: ליתיום
lithium in Hindi: लिथियम
lithium in Croatian: Litij
lithium in Haitian: Lityòm
lithium in Hungarian: Lítium
lithium in Armenian: Լիթիում
lithium in Indonesian: Litium
lithium in Ido: Litio
lithium in Icelandic: Litín
lithium in Italian: Litio
lithium in Japanese: リチウム
lithium in Lojban: roksodna
lithium in Javanese: Litium
lithium in Georgian: ლითიუმი
lithium in Korean: 리튬
lithium in Kölsch: Lithium
lithium in Kurdish: Lîtyûm
lithium in Latin: Lithium
lithium in Luxembourgish: Lithium
lithium in Lithuanian: Litis
lithium in Latvian: Litijs
lithium in Macedonian: Литиум
lithium in Malayalam: ലിഥിയം
lithium in Malay (macrolanguage): Litium
lithium in Low German: Lithium
lithium in Dutch: Lithium
lithium in Norwegian Nynorsk: Litium
lithium in Norwegian: Litium
lithium in Occitan (post 1500): Liti
lithium in Polish: Lit (pierwiastek)
lithium in Portuguese: Lítio
lithium in Quechua: Lityu
lithium in Romanian: Litiu
lithium in Russian: Литий
lithium in Sanskrit: लिथियम
lithium in Serbo-Croatian: Litij
lithium in Simple English: Lithium
lithium in Slovak: Lítium
lithium in Slovenian: Litij
lithium in Albanian: Litiumi
lithium in Serbian: Литијум
lithium in Swedish: Litium
lithium in Swahili (macrolanguage): Lithi
lithium in Tamil: லித்தியம்
lithium in Thai: ลิเทียม
lithium in Turkish: Lityum
lithium in Ukrainian: Літій
lithium in Uzbek: Litiy
lithium in Vietnamese: Liti
lithium in Walloon: Litiom
lithium in Yiddish: ליטיום
lithium in Chinese: 锂
lithium in Min Nan: Li (goân-sò͘)
lithium in Contenese: 鋰
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