Bismuth, Physical and Chemical Properties

Bismuth is a metalloid of no useful mechanical properties. It is mainly used as an alloying component in fusible alloys. Only one stable isotope, ²⁰⁹Bi, is known, but there are several unstable isotopes (¹⁹⁹Bi–²¹⁵Bi). Isotopes with mass number > 210 are found in the natural decay chains of radioactive elements. Isotopes with mass number < 208 have been formed in nuclear transformations. The volume of the molten metal increases by about 3% on solidification.

Physical Properties

Atomic number	83
Atomic weight	208.98
Relative abundance in Earth’s crust,%	2 × 10−5
Atomic radius, nm	0.18
Density at 20°C, g/cm3	9,790
Melting point, °C	271.40
Boiling point, °C	1,564
Crystal system	Rhombohedral
Lattice constant, nm	a = 0.47457
	α = 57.24°
Latent heat of fusion, J/mol	11,280
Latent heat of vaporization, J/mol	178,632
Coefficient of linear expansion, K−1	13.5 × 10−6
Electrical resistivity, μΩ cm
At 0°C	106.8
At 1,000°C	160.2
Specific heat at 25°C, J mol−1 K−1	25.5
Thermal conductivity, J s−1 m−1...