Gallium


 * Classification: || Gallium is an 'other metal' ||
 * Color: || silvery-blue ||
 * Atomic weight: || 69.723 ||
 * State: || solid ||
 * Melting point: || 29.76 oC, 302.91 K ||
 * Boiling point: || 2200 oC, 2673 K ||
 * Shells: || 2,8,18,3 ||
 * Electron configuration: || [Ar] 3d10 4s2 4p1 ||
 * Density @ 20oC: || 5.907 g/cm3 ||
 * Atomic volume: || 11.8 cm3/mol ||
 * Structure: || orthorhombic ||
 * Hardness: || 1.5 mohs ||

Discovery of Gallium
Before the discovery of gallium its existence and main properties were predicted by Dmitri Mendeleev. He named the hypothetical element eka-aluminum as he predicted the element would sit below aluminum on the periodic table. Gallium was discovered by Paul E. Lecoq de Boisbaudran through a spectroscope in 1875. Its now characteristic spectrum (two violet lines) identified it as a new element. De Boisbaudran extracted gallium in the first instance from a zinc blende ore from the Pyrenees and obtained initially only 0.65 grams from 430 kilograms of ore. He isolated gallium by electrolysis of its hydroxide in potassium hydroxide solution. The origin of the name comes from the Latin word 'Gallia', meaning France.

The major-use compound is Gallium Arsenide used in microwave circuitry and infrared applications.
Gallium is used as a dopant for the production of solid-state devices such as transistors. Gallium Nitride are used as a violet light source for higher-density compact disc data storage such as Blu-Ray Discs.

In [|semiconductors], the major-use compound is [|gallium arsenide] used in microwave circuitry and infrared applications. The compounds: [|Gallium nitride], and [|indium gallium nitride], are used in making minority semiconductors, that produce blue and violet [|light-emitting diodes] (LEDs) and [|diode lasers]. Semiconductor use is now almost the entire (> 95%) world market for gallium, but new uses in alloys and [|fuel cells] are continuing to be discovered. Gallium is not known to be essential in biology, but because of the biological handling of gallium's primary [|ionic salt] gallium(III) as though it were [|iron(III)], the gallium ion localizes to and interacts with many processes in the body in which iron(III) is manipulated. As these processes include [|inflammation], which is a marker for many disease states, several gallium salts are used, or are in development as both [|pharmaceuticals] and [|radiopharmaceuticals] in medicine.
 * Gallium** ([[image:http://upload.wikimedia.org/wikipedia/commons/thumb/8/8a/Loudspeaker.svg/11px-Loudspeaker.svg.png width="11" height="11" caption="play"]] [|/][|ˈ][|ɡ][|æ][|l][|i][|ə][|m][|/] [|//**gal**-ee-əm//]  ) is a [|chemical element] that has the symbol **Ga** and [|atomic number] 31. Elemental gallium does not occur in nature, but as the gallium(III) salt in trace amounts in [|bauxite] and [|zinc] ores. A soft silvery metallic [|poor metal], elemental gallium is a brittle solid at low temperatures. As it liquefies slightly above [|room temperature] , it will melt in the hand. Its melting point is used as a temperature reference point, and from its discovery in 1875 to the semiconductor era, its primary uses were in high-temperature thermometric applications and in preparation of metal alloys with unusual properties of stability, or ease of melting; some being liquid at room temperature or below. The alloy [|Galinstan] (68.5% Ga, 21.5% In, 10% Sn) has a melting point of about −19 °C (−2 °F).

Gallium has a very low melting point, therefore the heat of the human body is sufficient enough to melt this element The gallium scan is a type of nuclear scan involving radioactive gallium which helps determine whether a patient has inflammation in the lungs. Gallium is injected in a vein and a series of x-rays are taken to identify where the gallium has accumulated in the lungs. This test is most often performed when there is evidence of inflammation in the lungs (sarcoidosis).

=__Occurrence__= Gallium does not exist in free form in nature Gallium is found and extracted as a trace component in bauxite and to a small extent from sphalerite Extracted from coal, diaspore and germanite Gallium reserves to exceed 1 million tonnes, based on 50 ppm by weight concentration in known reserves of bauxite and zinc ores Some flue dusts from burning coal have been shown to contain small quantities of gallium, typically less than 1% by weight

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