An Overview about the Chemical Element Bismuth


Symbol: Bi

Atomic Number: 83

Atomic Mass: 208.98038 amu (atomic mass units)

Melting Point: 271.3 C (544.45 K, 520.33997 F)

Boiling Point: 1560.0 C (1833.15 K, 2840.0 F)

Number of Protons: 83

Number of Electrons: 83

Number of Neutrons: 126

Classification: Metal

Group Name: Pnictogen

Crystal Structure: Rhombohedral

Density @ 293 K: 9.8 grams per cubic centimeter

Color: white

Bismuth has been known since ancient times. Often it was confused with two other elements, tin and lead. In 1753 Claude Geoffroy the Younger was able to show that bismuth was, in fact, a distinct element. The name of the element comes from the German “Weisse Masse” which means white mass over time this changed to “Wisuth” and “Bisemutum”.

Until very recently bismuth-209 was thought to be the heaviest stable isotope to exist of any element. In 2002 it was found that it is, in fact, unstable. It decays by alpha decay to form thallium-205. Bismuth-209 does however have a very long half-life of approximately 19,000,000,000,000,000,000 years so scientists may be forgiven for thinking it was stable. Bismuth has a number of other isotopes with much shorter half-lives of between 182 microseconds (bismuth-207m) and 3,040,000 years (bismuth-210m). The mass numbers of these isotopes range from 196 to 217.

Pure bismuth metal is brittle. It is white with a faint pink hue.

Bismuth can be found free in nature and within the mineral ores bismuthinite and bismite. The largest deposits of bismuth containing minerals are to be found in Bolivia, South America. While these minerals are exploited most bismuth is produced commercially as a by-product from the extraction of lead, copper, silver, tin and gold. Bismuth and its compounds have a number of industrial uses.

* The most common use for bismuth metal is as a low melting point alloy with lead, cadmium, tin or iron. Low melting point alloys are used in fire detection and sprinkler systems as well as electrical fuses.

* The industry making acrylic fibers employs bismuth as a catalyst.

* It is used as a carrier for uranium fuel in nuclear reactors

* The compound bismuth oxide is a yellow pigment which has uses in paints and cosmetics.

* Bismuth oxychloride forms the pigment bismuth white.

A number of bismuth compounds are used in medicines.

* Bismuth carbonate is found in treatments for area and gastric ulcers.

* Tripotassium dicitratobismuthate is used to treat gastric upsets.

* Bismuth oxide and bismuth subgallate are found in hemorrhoid creams