Bismuth
Definition and meaning of Bismuth in chemistry.
Bismuth is a brittle, crystalline, white post-transition metal with a distinct pinkish tinge, possessing the chemical symbol Bi and atomic number 83. It is famously the most diamagnetic of all naturally occurring metals and has one of the lowest thermal conductivities observed in metallic elements.
In more detail
Bismuth is situated in group 15 of the periodic table, immediately following lead, and it shares numerous chemical and physical properties with its lighter group members arsenic and antimony. It occurs naturally both in its elemental native form and in common ores such as bismuthinite and bismite, and it is most often produced commercially as a byproduct of lead, copper, tin, silver, and gold mining operations. Uniquely among metals, bismuth expands slightly upon freezing from a liquid to a solid state, a rare physical property it shares with water (H2O). It is considered to be exceptionally chemically stable, although its only naturally occurring isotope, bismuth-209, is technically radioactive with a half-life vastly exceeding the estimated age of the universe. Because bismuth features very low toxicity to biological life, it is frequently utilized as a safer, heavier replacement for lead in various industrial and consumer applications.
Key facts
| Field | General Chemistry |
|---|---|
| Symbol | Bi |
| Atomic number | 83 |
| Atomic mass | 208.98 u |
| Category | Post Transition Metal |
| State at room temperature | Solid |
| Melting point | 271.5 °C (520.7 °F) |
| Density | 9.78 g/cm3 |
| Year discovered | Known since antiquity (recognized as distinct in 1753) |
Bismuth subsalicylate is the active chemical ingredient in many popular over-the-counter stomach remedies utilized to treat common human ailments like indigestion, heartburn, and diarrhea.
Frequently asked questions
Why is bismuth commonly used as a replacement for lead?
Bismuth shares many physical properties with lead, such as high density and a remarkably low melting point, but it completely lacks the severe neurological toxicity associated with heavy metals.
Is bismuth a completely stable element?
No, natural bismuth-209 is very weakly radioactive, slowly decaying via alpha particle emission with a half-life of roughly 1.9 x 10^19 years.