Lithium
See also: Lithium (homonymy)
The lithium is a chemical element, of symbol Li and Atomic number 3.
In the periodic Table, it is located in the group 1, among the alkaline metals.
Pure lithium is a soft Métal, of a silver plated white color, which tarnishes and oxidizes very quickly in contact with the air and of water.
It is the solid element lightest. It is mainly employed in conducting alloys of heat and the electric fencer .
History
Lithium (of the Greek lithographies meaning “stone”) was discovered by Johan August Arfwedson in 1817.Arfvedson discovered a new salt by analyzing minerals of Pétalite, Spodumène and Lépidolite coming from the island of Utö in Sweden.
In 1818, Christian Gmelin (1792 - 1860) were the first to observe that these salts (lithium) gave a red and brilliant flame.
However, the two men sought to isolate the element from its salt but did not arrive there. The element was isolated by electrolysis from an oxide from lithium by William Thomas Brande and Sir Humphry Davy. One gave him the lithium name to recall that he was discovered in the mineral kingdom.
The commercial production of lithium began in 1923 with the German firm Metallgesellschaft AG which used the electrolysis of a mixture of chloride molten potassium lithium and chloride.
Properties
Lithium is metal having the lowest molar mass and lightest, with a Densité equal to half of that of water. In accordance with Law of Dulong and Petit, it is the solid having largest Specific heat.Like other alkaline metals, lithium reacts easily with water (but less than the Sodium); there does not exist with the native state.
When it is placed above a flame, this one takes a crimson color but when it starts to burn, the flame becomes of a white very shining. In solution, it forms Li+ ions.
Use
Lithium is often used like Anode of battery because of its large Electrochemical potential. The batteries lithium are very much used in the field of the systems embarked because of their great energy density as well mass as voluminal.
Other uses:
- the Salts of lithium, as the lithium carbonate, the lithium citrate or the Orotate of lithium are used like regulator of mood for the treatment of the bipolar turbid (in the past maniaco-depressive psychosis );
- the Lithium gluconate is used in dermatology like anti-allergenic;
- lithium is used in the sleep disorders and irritability in oligothérapie;
- the lithium chloride and the lithium bromide are extremely hygroscopic and are used like desiccants;
- lithium is a sequestering agent used for the synthesis of made up organics;
- lithium is sometimes used in the Verre S and the Céramique S with weak thermal expansion, such as for example for the lens of 200 inches of the Télescope Hauls Mont Palomar;
- the Hydroxyde of lithium is employed to extract the CO2 from the air in the confined surroundings like the space capsules and the Sous-marin S;
- the alloys high efficiency lithium Aluminum, Cadmium, Copper and Manganèse are used with manufacture as parts for Aéronef;
- lithium salts are used for the transfer of heat by convection;
- for the production of Tritium by nuclear reaction. The tritium is used for the nuclear Fusion.
- lithium is, with potassium, one of two alkaline having a stable isotope fermionic, from where its interest for the study of the degenerated fermionic gases ultrafroids.
Lithium 6 is a nuclear matter whose detention is regulated (R1333-1 Article of the code of defense).
See also: Control of the nuclear matters
Layers
Lithium is widely distributed on planet, but one does not find it in his metal form because of his great reactivity. One finds it mainly like impurity in salts of other alkaline metals.
The largest layer in the world is the Salar del Hombre Muerto, in the Département of Antofagasta of the Sierra, located at the North-West of the Argentine.
Environment
Metal lithium reacts with nitrogen, the oxygen and the steam in the air. Consequently, the lithium surface becomes a lithium hydroxide mixture (LiOH), of carbonate of lithium (Li2CO3) and nitride of lithium (Li3N). The hydroxide lithium presents a significant possible hazard because it is extremely corrosive. A special attention should be given for the watery organizations.
See too
lithium|lithium- Battery lithium
- Pile with lithium
Be-X-old: Ліцій Simple: Lithium Zh-min-nan: Li (goân-sò͘) Zh-yue: 鋰
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