Bismuth

lead - bismuth - polonium Sb Bi Uup       Full table
General
Name, Symbol, Number	Bismuth, Bi, 83
Chemical series	Poor metals
Group, Period, Block	15 (VA), 6, p
Density, Hardness	9.78 g/cm3, 2.25
Appearance	lustrous reddish white Missing image Bi,83.jpg
Atomic properties
Atomic weight	208.98038 g/mol
Atomic radius (calc.)	160 (143) pm
Covalent radius	146 pm
van der Waals radius	no data
Electron configuration	[Xe]4f14 5d10 6s2 6p3
e- 's per energy level	2, 8, 18, 32, 18, 5
Oxidation states (Oxide)	3, 5 (mildly acidic)
Crystal structure	Rhombohedral
Physical properties
State of matter	Solid (diamagnetic)
Melting point	544.4 K (520.3 ?F)
Boiling point	1837 K (2847 ?F)
Molar volume	21.31 cm3/mol
Heat of vaporization	104.8 kJ/mol
Heat of fusion	11.3 kJ/mol
Vapor pressure	0.000627 Pa at 544 K
Speed of sound	1790 m/s at 20 ?C
Miscellaneous
Electronegativity	2.02 (Pauling scale)
Specific heat capacity	122 J/(kg·K)
Electrical conductivity	0.867 MS/m
Thermal conductivity	07.87 W/(m?K)
1st ionization potential	703 kJ/mol
2nd ionization potential	1610 kJ/mol
3rd ionization potential	2466 kJ/mol
4th ionization potential	4370 kJ/mol
5th ionization potential	5400 kJ/mol
6th ionization potential	8520 kJ/mol
Most stable isotopes
iso NA half-life (not SI) DM DE MeV (not SI) DP 207Bi {syn.} 31.55 y ε 2.399 207Pb 208Bi {syn.} 3,368,000 y ε 2.880 208Pb 209Bi 100% (1.9?0.2) ×1019y α   205 Tl
SI units & STP are used except where noted.

Bismuth is a chemical element in the periodic table that has the symbol Bi and atomic number 83. This heavy, brittle, white crystalline trivalent poor metal 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. Lead-free bismuth compounds are used in cosmetics and in medical procedures.

Contents

1 Notable characteristics 2 Applications 3 Crystals 4 History 5 Occurrence 6 References 7 External links

Notable characteristics

It 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. When heated in air bismuth burns with a blue flame and its oxide forms yellow fumes.

Bismuth has long been thought to be unstable on theoretical grounds, but not until 2003 was this demonstrated when researchers at the Institut d'Astrophysique Spatiale in Orsay, France measured the alpha emission half-life of Bi-209 to be 1.9 × 10¹⁹ years, meaning that bismuth is not truly stable, with a half-life over a billion times longer than the current estimated age of the universe. Due to this phenomenal half-life, bismuth can be treated as if it is stable and non-radioactive. Ordinary food containing typical amounts of carbon 14 is many thousands of times more radioactive than bismuth, as are our own bodies. However, the radioactivity is of academic interest because bismuth is one of few elements whose radioactivity was suspected, and indeed theoretically predicted, before being detected in the lab.

A hypothetical immortal who lost a digestive bacterium every year, or a hair every several thousand years, would lose mass more rapidly than a sample of bismuth decays.

Applications

Bismuth oxychloride is extensively used in cosmetics and bismuth subnitrate and subcarbonate are used in medicine. Bismuth subsalicylate (Pepto-Bismol?) is used as an antidiarrheal. [1] (http://www.healthcentral.com/mhc/top/001852.cfm)

Some other uses are:

• Strong permanent magnets can be made from the alloy bismanol (MnBi).
• Many bismuth alloys have low melting points and are widely used for fire detection and suppression system safety devices.
• Bismuth is used in producing malleable irons.
• Bismuth is finding use as a catalyst for making acrylic fibers.
• Also used as a thermocouple material.
• A carrier for U-235 or U-233 fuel in nuclear reactors.
• Bismuth has also been used in solders. The fact that bismuth and many of its alloys expand slightly when they freeze make them ideal for this purpose.
• Bismuth subnitrate is a component of glazes that produces an iridescent luster finish.

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, as a substitute of lead in free-machining brasses for plumbing applications and free-cutting steels for precision machining properties, used in producing malleable irons, as a catalyst for making acrylic fibres, the metal is used as a thermocouple material (has highest negativity known), carrier for uranium fuel in nuclear reactors, fire detection, extinguishing systems, cosmetics, medicine, lubricating greases, and shot for waterfowl hunting.

Crystals

Though virtually unseen in nature, high-purity bismuth can form into distinctive hopper crystals. These colorful laboratory creations are typically sold to hobbyists.

History

Bismuth (New Latin bisemutum from German Wismuth, perhaps from weisse Masse, "white mass") was confused in early times with tin and lead due to its resemblance to those elements. Claude Geoffroy Junine showed in 1753 that this metal is distinct from lead.

Occurrence

The most important ores of bismuth are bismuthinite and bismite. Canada, Bolivia, Japan, Mexico, and Peru are major producers. Bismuth produced in the United States is obtained as a by-product of copper, gold, silver, tin and especially lead ore processing. The average price for bismuth in 2000 was US$7.70 per kilogram.

References

• Los Alamos National Laboratory - Bismuth (http://periodic.lanl.gov/elements/83.html)

External links

• WebElements.com - Bismuth (http://www.webelements.com/webelements/elements/text/Bi/index.html)
• EnvironmentalChemistry.com - Bismuth (http://environmentalchemistry.com/yogi/periodic/Bi.html)
• Bismuth breaks half-life record for alpha decay (http://physicsweb.org/article/news/7/4/16)