Gallium :: essays research papers

tabun1871 Dmitrii Ivanovich Mendelev predicts the existance and properties of the cistron after zinc in the periodic table. He Gives it the name "eka atomic number 13".1875 Paul Emile Lecoq de Boisbaudran disc everywheres gallium. Its properties closelymatch those predicted by Mendelev.     Gallium, atomic number 31, is precise similar to aluminum in its chemicalproperties. It does not dissolve in nitric acid because of the protective filmof gallium oxide that is formed over the surface by the action of the acid.Gallium does however dissolve in other acids, and alkalies.     Gallium was discovered (1875) by Paul Emile Lecoq de Boisbaudran, whoobserved its headliner spectral lines while examining material seperated fromzinc blende. Soon after he isolated the metal studied its properties, whichcoincided those that Dmitrii Ivanovich Mendelev had predicted a few years prior for eka-aluminium, the then undiscovered element lying between aluminumand atomic number 49 in his periodic table.     Though widely distributed at the Earths surface, gallium does not occorfree or concentrated in independant minerals, except for gallite. It isextracted as a by-product from zinc blende, iron pyrites, bauxite, andgermanite.     Silvery white and soft bountiful to be cut with a knife, gallium takes on a spicy tinge because of superficial oxidation. Unusual for its low meltingpoint ( rough 30 degrees C, 86 degrees F ), gallium also expands uponsolidification and supercools readily, be a liquid at temperatures aslow as 0 degrees C ( 32 degrees F ).     Gallium has the longest usefull liquid chemical chain of both element. The liquidmetal clings to glass and similar surfaces. The crystal body structure of galliumis orthorhombic. Natural gallium consists of a mixture of two shelter isotopesgallium-69 ( 60.4 percent ) and gallium-71 (39.6 percent ).   &nbs p Somewhat similar to aluminum chemically, gallium easily oxidizes inmoist air until a protective film forms, and it becomes peaceable in cold nitricacid.     Gallium has been considered as a assertable heat-exchange medium innuclear reactors, although it has a high neutron cross section. radioactivegallium-72 shows some promise in the study of bone cancer a compound of thisisotope is absorbed by the cancerous portion of the bone.     The most ballpark use of gallium is in a gallium scan. Gallium scans beoften used to diagnose and follow the progression of tumors or infections.Gallium scans can also be used to evaluate the heart, lungs, or any other organthat may be involved with inflammatory disease.