Science Fair Project Encyclopedia
|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 |
|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)|
|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|
|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|
|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.
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 ± 0.2) × 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.
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, lubricating greases, and shot for waterfowl hunting.
Though virtually unseen in nature, high-purity bismuth can form into distinctive hopper crystals. These colorful laboratory creations are typically sold to hobbyists.
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.
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.
- WebElements.com - Bismuth
- EnvironmentalChemistry.com - Bismuth
- Bismuth breaks half-life record for alpha decay
The contents of this article is licensed from www.wikipedia.org under the GNU Free Documentation License. Click here to see the transparent copy and copyright details