Bismuth

Symbol: Bi
Atomic number: 83
Category: poor metals
Group: 15
Period: 6
Block: p
Atomic weight: 208.98040 g/mol
Electrons per shell: 2, 8, 18, 32, 18, 5
CAS number: 7440-69-9
Phase: solid
Density: 9.78 kg/dm³ (near room temperature)
Melting point: 544.7 K (271.5 °C, 520.7 °F)
Boiling point: 1837 K (1564 °C, 2847 °F)
Crystal structure: rhombohedral
Oxidation states: 3, 5
Electronegativity: 2.02 (Pauling scale)
Name's origin: Wismuth
Name's meaning: the German word for 'white mass'
Facts:
- a heavy, brittle, white crystalline trivalent poor metal which has a pink tinge and chemically resembles arsenic and antimony
- is the most naturally diamagnetic, and only mercury has a lower thermal conductivity
- is generally considered to be the last naturally occurring stable, non-radioactive element on the periodic table, although it is actually slightly radioactive, with an extremely long half-life: 1.9 x 10¹⁹ years
- bismuth compounds are used as catalysts in the manufacturing process of synthetic fiber and rubber
- as the toxicity of lead has become more apparent in recent years, alloy uses for bismuth metal as a replacement for lead have become an increasing part of bismuth's commercial importance
- is about twice as abundant as gold in the Earth's crust
- is not known to be toxic, compared to its periodic table neighbours (lead, antimony, and polonium), although some compounds (including bismuth chloride due to its corrosive acidity) are toxic and should be handled with care
- overexposure to bismuth can result in the formation of a black deposit on the gingiva, known as a bismuth line
- is usually produced as a byproduct of the processing of other metal ores, especially lead, tungsten, tin, copper, and also silver