← Periodic table · Post-transition metals
Bismuth (Bi)
Bismuth (symbol Bi) is the chemical element with atomic number 83: a post-transition metal, solid at 0 °C, with an atomic mass of 208.98 u. Discovered in 1753 (Claude François Geoffroy).
Bismuth is a paradoxical heavy metal: a neighbor of lead and polonium, yet so low in toxicity that people swallow it in stomach remedies. It forms iridescent staircase crystals in every color. It was long thought to be stable, until it was found in 2003 to be radioactive… with a colossal half-life.
Key facts
- Atomic number
- 83
- Symbol
- Bi
- French name
- Bismuth
- Atomic mass
- 208.98 u
- Molar mass
- 208.98 g/mol
- Family
- Post-transition metals
- Position
- period 6, group 15, p-block
- State at 0 °C
- Solid
- Melting point
- 271.6 °C
- Boiling point
- 1,563.9 °C
- Density
- 9.78 g/cm³
- Electronegativity (Pauling)
- 2.02
- First ionization energy
- 703 kJ/mol
- Atomic radius
- 160 pm
- Electron configuration
- [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p³
- Abundance in Earth's crust
- 0.0085 ppm (71st most abundant element)
- Indicative price
- 6 $/kg (order of magnitude)
- Radioactive
- no
- Discovery
- 1753, Claude François Geoffroy
Origin of the name
From the German Wismut, of uncertain origin.
What does bismuth look like?
A brittle, silvery-white metal with a pinkish sheen. Its lab-grown crystals, shaped like hollow staircases, flash vivid colors thanks to a thin oxide layer.
Where is bismuth found?
About 0.009 ppm of Earth's crust, nearly ten times less than silver. It occurs mainly as traces in lead, copper and tungsten ores.
Natural sources
- Bismuthinite
- Bismite
- Native bismuth
How is bismuth produced?
Mostly a by-product of refining lead, copper and tungsten. China accounts for the vast majority of world production.
Top producers
- China
- Laos
- South Korea
- Japan
What is bismuth used for?
- Stomach medicines (bismuth subsalicylate and subcitrate).
- Pearly pigment in cosmetics (bismuth oxychloride).
- Low-melting alloys in fire-sprinkler heads.
- A non-toxic substitute for lead: solders, plumbing brass, hunting shot and fishing weights.
In everyday life
- Pepto-Bismol or an antacid
- Pearly eyeshadow or nail polish
- A ceiling fire sprinkler
- An iridescent bismuth crystal from a rock shop
Role in living things
No biological role. It is used against the bacterium Helicobacter pylori, which causes stomach ulcers.
Hazards of bismuth
Remarkably low toxicity for a heavy metal. Overuse of bismuth medicines can, however, turn the tongue and stools black, and prolonged overdoses have caused neurological problems.
Cosmic origin
- Dying stars: Made slowly in red giants (stars like the Sun at the end of their lives).
- Neutron stars: Created when two neutron stars collide — the “forge” of gold.
History of bismuth
Known since the Middle Ages, it was long confused with tin and lead. In 1753 the Frenchman Claude François Geoffroy showed it was a distinct metal. Its name is thought to come from the German Wismut, of uncertain origin.
Did you know?
- In 2003, a team at the Institute of Space Astrophysics in Orsay, France, measured the half-life of bismuth-209: about 2 × 10¹⁹ years, more than a billion times the age of the universe.
- Like water, it expands as it solidifies.
- It is the most diamagnetic element: magnets repel it, so much so that a strong magnet can levitate above a block of bismuth.
Isotopes of bismuth
Bismuth-209, its only natural isotope, was long believed to be stable. In 2003 it was found to be radioactive, with a half-life more than a billion times the age of the Universe.
- bismuth-207: radioactive, half-life 31.6 years. A reference source for calibrating radiation detectors.
- bismuth-209: 100% of natural bismuth, radioactive, half-life 2.01 × 10¹⁹ years. Decays so slowly that it is practically stable: its decay was only detected in 2003.
- bismuth-210: radioactive, half-life 5.01 days
- bismuth-212: radioactive, half-life 1.01 h
- bismuth-213: radioactive, half-life 45.6 min. Targeted alpha therapy for some leukemias and tumors.
- bismuth-214: radioactive, half-life 19.9 min
Related elements
Same family (post-transition metals): Aluminium (Al), Gallium (Ga), Indium (In), Tin (Sn), Thallium (Tl), Lead (Pb), Polonium (Po).
Same column (group 15): Nitrogen (N), Phosphorus (P), Arsenic (As), Antimony (Sb), Moscovium (Mc).