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83 Bi 208.98040(1)

Bismuth

Poor metal
Symbol Bi
Atomic Number 83
Atomic Weight 208.98040(1)
CAS Registry ID 7440-69-9
Group Name Pnictogen
Period Number 6
Block p-block
State at STP Solid

Description

Sample of Bismuth ⌕ Enlarge Image

Bismuth is one of the poor metals that is a bright pink color in its natural solid state. It is the most diamagnetic metal, and in the right conditions it has semi-conductive characteristics. Bismuth has an atomic weight of 208.98040, a melting point of 520.7 °F, and a boiling point of 2847 °F. Some common uses of bismuth include: as an active ingredient in anti-diarrhea medications, as a component in some alloys, as a carrier for fuel in nuclear reactors, and as a component in some glazes.

Isolation

Bismuth is extracted and isolated from such ores as bismuthinite and bismite. It is also collected as a by-product from other metal ore processing.

Bismuth ⌕ Enlarge Image

Bismuthinite is a mineral composed of bismuth sulfide and it often occurs with lead and copper ore, and bismite is composed of bismuth oxide. The isolation techniques used to extract pure bismuth from these ores is relatively simple. Most of the bismuth collected for commercial uses is extracted as a by product from copper, gold, lead, silver, and tin processing. Smelting processes used to separate these ores results in bismuth isolation. Smelting is a type of extractive metallurgy that is used to isolate metals from the ores that they are found in. During the smelting process, carbon in the form of coke serves as a reducing agent to reduce the oxidized states of the ore. This process can be used on bismuth by-products from ore processing, or directly on the bismite mineral. The carbon reacts with the oxygen producing carbon monoxide, or carbon dioxide, to leave the metal. Contaminants usually remain, and additional reduction using charcoal or coke further reduce and isolate the bismuth.

General

NameBismuth
SymbolBi
Number83
Chemical seriesPoor metal
Group15
Period6
Blockp
Appearancelustrous pink
Standard atomic weight208.98040(1) g·mol⁻¹
Electron configuration[Xe] 4f14 5d10 6s2 6p3
Electrons per shell2, 8, 18, 32, 18, 5

Atomic Properties

Crystal structurerhombohedral
Oxidation states3, 5 (mildly acidic oxide)
Electronegativity2.02 (scale Pauling)
Ionization energies1st:  703  kJ·mol−1
2nd:  1610  kJ·mol−1
3rd:  2466  kJ·mol−1
Atomic radius160 pm
Atomic radius (calc.)143 pm
Covalent radius146 pm
Van der Waals radius

Physical Properties

Phasesolid
Density (near r.t.)9.78  g·cm−3
Liquid density at m.p.10.05  g·cm−3
Melting point544.7 K (271.5 °C, 520.7 °F)
Boiling point1837 K (1564 °C, 2847 °F)
Critical point
Heat of fusion11.30  kJ·mol−1
Heat of vaporization151  kJ·mol−1
Heat capacity(25 °C) 25.52  J·mol−1·K−1

Miscellaneous

Magnetic orderingdiamagnetic
Electrical resistivity(20 °C) 1.29 µ Ω·m
Thermal conductivity(300 K) 7.97  W·m−1·K−1
Thermal expansion(25 °C) 13.4  µm·m−1·K−1
Speed of sound (thin rod)(20 °C) 1790 m/s
Young's modulus32 GPa
Shear modulus12 GPa
Bulk modulus31 GPa
Poisson ratio0.33
Mohs hardness2.25
Vickers hardness
Brinell hardness94.2 MPa