ELEMENTLE

Element 83 · Metal

Bismuth

Period 6 · Group 15

Bismuth is a chemical element with symbol Bi and atomic number 83. Bismuth, a pentavalent post-transition metal, chemically resembles arsenic and antimony. Elemental bismuth may occur naturally, although its sulfide and oxide form important commercial ores.

Three reasons Bismuth stands out

  1. 1

    Non-toxic metal with a beautiful rainbow-colored surface.

  2. 2

    The active ingredient in the pink stomach medicine Pepto-Bismol is a compound of this metal.

  3. 3

    Although technically radioactive, its most stable isotope has a half-life roughly a billion times longer than the age of the universe.

The rainbow metal with a nearly eternal isotope

Bismuth crystals grow stepped shapes and acquire iridescent oxide films that create their familiar rainbow colors. The element is far less toxic than neighboring lead and appears in medicines and low-melting alloys. Bismuth-209 is radioactive, but its half-life is vastly longer than the age of the universe.

Recognizing Bismuth in Elementle

If Bismuth is the mystery element, guesses below atomic number 83 point up and guesses above it point down. Its symbol is Bi: a green letter matches the same position in that symbol, while a yellow letter belongs in another position.

The family clue turns green for metal guesses. Compare Lead (Pb), number 82 and Polonium (Po), number 84: they share the family clue, but their atomic numbers and symbols help you tell them apart.

Learn how to read the clues or play the daily element guessing game.

Bismuth at a glance
Atomic number / protons83
SymbolBi
Family (Elementle)Metal
Classification (PubChem)Post-transition metal
Period6
Group15
Atomic mass (u)208.98040
Standard stateSolid
Electron configuration[Xe]6s2 4f14 5d10 6p3
Reported oxidation states+5, +3
Electronegativity (Pauling)2.02
Atomic radius (pm)207
First ionization energy (eV)7.289
Electron affinity (eV)0.946
Density (g/cm³)9.807
Melting point544.55 K (271.4 °C)
Boiling point1837 K (1,563.85 °C)
Discovery (PubChem)1753

Values are reference data, not a specification for every temperature, pressure, or allotrope. Unknown properties are left unavailable. Superheavy-element predictions remain uncertain.

Sources & further reading

PubChem: Bismuth · Bismuth on Wikipedia

The introduction and original editorial story are adapted from Wikipedia contributors via Periodic-Table-JSON. Element descriptions and their adaptations are available under CC BY-SA 3.0. Numerical attributes use the PubChem periodic-table dataset, retrieved September 22, 2026.