The chemical element Bismuth is a metal present in group number 15 of the periodic table. Its atomic number is 83 and its atomic mass is 208.98. Bismuth has 83 electrons in the single neutral atom. It contains 83 protons and 126 neutrons in its nucleus. Bismuth is represented by the symbol “Bi”.
Naming and History
The name bismuth is most probably the Latinized form of the German word “Weissmuth” which means white substance. It was possibly due to its white oxide. The name later changed to “Wisuth” and “Bisemutum”.
- Agricola and Casper Neuman
Bismuth was discovered around 1400 AD. It was confused with lead or considered some form of lead. In the 1500s Agricola found that it was different metal. In the 1700s, Casper Neuman also showed it different metals.
- Claude Geoffrey
French chemist, Claude Geoffrey in 1753, finally proved that bismuth was a different element rather than any form of lead.
Occurrence of Bismuth
Bismuth occurs in nature in both native metal and ores form. The main ores of bismuth are bismuthimite and bismite. It can also be obtained from the ores of nickel, copper, lead, cobalt, silver, and tin as by-products.
The smelting of copper can be a source of bismuth. The large deposits of bismuth are found in Bolivia, Peru, Canada, Mexico, and Japan.
Properties of Bismuth
Pure bismuth metal is a crystalline, white, and brittle metal with a slight pinkish color. Bismuth salts are insoluble in water and it is stable to water and oxygen. Except for mercury, Bismuth has the lowest thermal conductivity of any metal.
It has very high electrical resistance. Bismuth is a natural diamagnetic. It has the highest value for the Hall effect. For low melting alloys, it is usually mixed with other metals such as lead, copper, cobalt, etc.
The melting point of bismuth is 271.40°C and its boiling point is 1564°C. It has a density of 9.807 grams per cubic centimeter. Bismuth exists as solid at room temperature.
Bismuth in Biological Systems
There is no significant and known role of bismuth in living organisms and living systems. It is considered to be a non-toxic element.
Uses of Bismuth
- On alloying with metals of a low melting point such as cadmium and iron, it is used in fire detection systems, fire sprinkler systems, electric fuses, solders, and extinguishers.
- In the chemical industry, it is used as a catalyst for acrylonitrile.
- It has pharmaceutical importance and uses. Bismuth carbonate is used for treating diarrhea and ulcers.
- Bismuth oxide produces yellow pigment which is used in cosmetics and paints.
- It is sometimes used in shots, shotguns, low toxicity bird shots, and fishing sinkers.
Isotopes of Bismuth
There are almost 33 known isotopes of bismuth whose mass number ranging from 185 to 217. It has no stable isotopes but Bi- 209 is considered comparatively stable which is also radioactive with a half-life of 1.9 x 10 19 years.