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History and Production
From German Weisse Masse, meaning white mass. It was later changed to bisemutum by G. Bauer in 1530. Bismuth has been known as a metal since 1480 and used as casting alloy in printing press. The main commecial source of the metal is recovered from byproducts of lead/zinc and copper mining plants, from which bismuth can be cast out in iron and steel vessels.
It combines with tin and cadmium to give low melting point alloys which are used for making safety devices in fire detection system and extinguishing system. It is also used as metallurgical additives such as in producing malleable irons.
It is also used as a catalyst for making acrylic fibers.
Physical Data
Bismuth is a brittle metal with a pinkish tinge. It is the most diamagnetic of all metals with a very low thermal conductivity. It has also the highest Hall effect of any metal. It is quite rare in earth, about 0.008 ppm and occurs mainly as bismite (a-Bi2O3) and bismuthinte (Bi2S3). It may also occur native.
Interatomic distance: 309.0 pm
Melting point: 271.4°C
Boiling point: 1564°C
Thermal conductivity/Wm-1K-1: 7.87 (27°C)
Density/kgm-3: 9747 (20°C), 10050 (m.p.)
Standard Thermodynamic Data (atomic gas)
Enthalpy of formation: 207.1 kJ/mol
Gibbs free energy of formation: 168.2 kJ/mol
Entropy: 187.0 J/mol K
Heat capacity: 20.8 J/mol K
Electronic data
Electronic configuration: [Xe] 4f14 5d10 6s2 6p3
Term symbol: 4S3/2
Electron affinity: 91.2752 kJ/mol Electronegativity (Pauline): 1.90
Ionization energy (first, second, third): 702.954, 1610.34, 2466.17 kJ/mol
Chemical properties
Chemically bismuth is not very reactive. It does not react with water and dilute sulfuric acid, even with cold concentrated sulfuric acid.
However, it reacts with nitric acid to give bismuth(III) nitrate, which readily hydrolyses in water to give bismuthyl ion, BiO+, that
readily forms a precipitate with any anion present. The same effect is also observed for for bismuth salts such as the chloride and sulfate.
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