Bismuth is a metallic chemical element with atomic weight 208.98038 amu.  It is a chemical element in the periodic table that has the symbol Bi and atomic number 83. This is heavy, brittle, white crystalline trivalent true metal that has a pink tinge and chemically resembles arsenic and antimony. Most diamagnetic of all metals, bismuth has the lowest thermal conductivity of all the elements except mercury.

Characteristics

• Melting Point: 271.3 °C (544.45 °K, 520.33997 °F)
• Boiling Point: 1560.0 °C (1833.15 °K, 2840.0 °F)
• Number of Protons/Electrons: 83
• Number of Neutrons: 126
• Classification: Other Metals
• Crystal Structure: Rhombohedral
• Density @ 293 K: 9.8 g/cm3
• Color: white

Bismuth is the heaviest stable element and is a brittle metal with a pinkish hue with an iridescent tarnish. Among the heavy metals, it is the heaviest and the only non-toxic. No other metal is more diamagnetic than bismuth, except mercury. This metal, which occurs in its native form, has a high electrical resistance and also has the highest Hall effect of any metal (that is, it has the greatest increase in electrical resistance when it is placed in a magnetic field). When heated in air bismuth burns with a blue flame and its oxide forms yellow fumes.

Applications

Bismuth oxychloride is extensively used in cosmetics and bismuth subnitrate and subcarbonate are used in medicine. Other uses; "Bismanol" (MnBi) is a permanent magnet. Bismuth alloys have low-melting temperature and are widely used for fire detection and suppression system safety devices. Bismuth is used in producing malleable irons and is finding use as a catalyst for making acrylic fibers. Also used as a thermocouple material. A carrier for U-235 or U233 fuel in nuclear reactors. Bismuth has also been used in solders.

In the early 1990s, research began on the evaluation of bismuth as a nontoxic replacement for lead in such uses as ceramic glazes, fishing sinkers, food processing equipment, free-machining brasses for plumbing applications, lubricating greases, and shot for waterfowl hunting.

History

Bismuth was probably unknown to the Greeks and Romans, but during the middle ages it became quite familiar, notwithstanding its frequent confusion with other metals. In 1450 Basil Valentine referred to it by the name “wismut,” and characterized it as a metal; some years later Paracelsus termed it “ wissmat,” and, in allusion to its brittle nature, affirmed it to be a “bastard” or “half-metal”; Georgius Agricola used the form “ wissmuth,” latinized to “ bisemutum,” and also the term “plumbum cineareum.” Its elementary nature was imperfectly understood; and the impure specimens obtained by the early chemists explain, in some measure, its confusion with tin, lead, antimony’, zinc and other metals; in 1595 Andreas Libavius confused it with antimony, and in 1675 Nicolas Lemery with zinc. These obscurities began to be finally cleared up with the researches of Johann Heinrich Pott (1692— 1777), a pupil of Stahl, published in his Exercitationes chemicae de Wismutho (1769), and of N. Geoffroy, son of Claude Joseph Geoffroy, whose contribution to our knowledge of this metal appeared in the Mémoires de l’académie francaise for 1753. Torbern Olof Bergman reinvestigated its properties and determined its reactions; his account, which was published in his Opuscula, contains the first fairly accurate description of the metal.

Occurrence

Bismuthinite and bismite are the most important ores of bismuth. Canada, Bolivia, Japan, Mexico, and Peru are major producers. Bismuth produced in the United States is obtained as a by-product of copper, gold, lead, silver, tin and especially lead ore processing. The average price for bismuth in 2000 was US$ 3.50 per pound.

This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia.