Bismuth is an element of the periodic table with an atomic number of 83 with the symbol Bi and. It is a brittle white metal with a pinkish tinge. It is located in Group V of the Periodic Table with nitrogen, phosphorus, arsenic, and antimony. It resembles antimony in its mode of occurrence but is less common. Elemental Bi may occur naturally, although its sulfide and oxide form important commercial ores. It is the most naturally diamagnetic element, and has one of the lowest values of thermal conductivity among metals.
The content of bismuth in the earth’s crust has been estimated to be 0.00002 weight %, about the same abundance as silver. Its cosmic abundance is estimated to be at about one atom per 107 atoms of silicon. The metallic properties of bismuth are more pronounced than that of either antimony or arsenic. Due to its higher growth rate around the outer sides than on the inner sides bismuth crystals form a spiral, stair-stepped structure.
Characteristics of Bismuth
- It is a brittle metal with a white, silver-pink hue, often with an iridescent oxide tarnish showing many colors from yellow to blue.
- The spiral, stair-stepped structure of bismuth crystals is the result of a higher growth rate around the outside edges than on the inside edges.
- The variations in the thickness of the oxide layer that forms on the surface of the crystal cause different wavelengths of light to interfere upon reflection, thus displaying a rainbow of colors.
- When burned in oxygen, Bi burns with a blue flame and its oxide forms yellow fumes. Its toxicity is much lower than that of its neighbors in the periodic table, such as lead, antimony, and polonium.
Uses of Bi
- It is used in extinguishers, electric fuses, and fire detectors.
- Certain bismuth compounds are also manufactured and used as pharmaceuticals.
- Industry makes use of bismuth compounds as catalysts in manufacturing acrylonitrile, the starting material for synthetic fibers and rubbers.
- It is occasionally used in the production of shot and shotguns.