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83Bi208.98

Bismuth (Bi)

Post-transition metal

Bismuth is the heaviest element with an (almost) stable heart — its one natural isotope decays so slowly it outlives the universe many times over. It forms stunning rainbow-stepped crystals and soothes upset stomachs.

Group: 15Period: 6Block: pState at 25 °C: Solid

Position on the periodic table

Fun fact: Lab-grown bismuth crystals form iridescent, staircase-like “hopper” shapes straight out of science fiction.

Atomic properties

Atomic number83
Atomic mass208.98 amu
Electron configuration1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d10 6p3
Noble gas shorthand[Xe] 4f14 5d10 6s2 6p3
Electrons per shell2, 8, 18, 32, 18, 5
Valence electrons (outer shell)5
Common oxidation states+3, +5
Electronegativity (Pauling)2.02
Covalent radius (approx.)148 pm
First ionization energy703 kJ/mol
Electron affinity90.9 kJ/mol

Physical properties

State at 25 °CSolid
Density9.78 g/cm³
Melting point271.55 °C (544.7 K)
Boiling point1563.8 °C (1837 K)
Appearancelustrous silver
RadioactiveNo
OriginOccurs naturally

Electron configuration of bismuth

Bismuth's ground-state electron configuration is 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d10 6p3, usually shortened to [Xe] 4f14 5d10 6s2 6p3. Its electrons occupy 6 shells (2, 8, 18, 32, 18, 5), placing it in period 6 of the p-block. The 5 outer-shell electrons drive its bonding behaviour. Explore it interactively in the electron configuration calculator.

Uses of bismuth

  • Stomach remedies (bismuth subsalicylate)
  • Non-toxic replacement for lead in solder, shot and fishing weights
  • Low-melting safety alloys for fire sprinklers
  • Cosmetic pearlescent pigments

Biological role: None essential; some compounds are used medicinally.

Occurrence: By-product of lead, copper and tin refining.

Common compounds of bismuth

Bi2O3

Bismuth(III) oxide

Molar mass →

BiOCl

Bismuth oxychloride (cosmetics)

Molar mass →

History and discovery

Discovered: 1753 — Claude François Geoffroy. Name origin: Probably from German wismut, of uncertain meaning.

Confused with lead and tin for centuries; Claude Geoffroy the Younger established it as distinct in 1753.

Safety notes

Remarkably non-toxic for a heavy metal — hence its role replacing lead.

Educational context only — always follow your school's laboratory rules and never handle chemicals without proper supervision. See our disclaimer.

Practice questions

Quick practice: Bismuth

1. What is the chemical symbol of Bismuth?

2. What is the atomic number of Bismuth?

3. Which category does Bismuth belong to?

4. What is the state of Bismuth at room temperature?

5. Which period of the periodic table is Bismuth in?

Want more? Try the full quizzes →

Bismuth FAQs

What is the atomic number of bismuth?

Bismuth's atomic number is 83 — every bismuth atom has 83 protons in its nucleus.

What is the symbol for bismuth?

Bi. Probably from German wismut, of uncertain meaning.

Is bismuth a metal, nonmetal, or metalloid?

Bismuth is classified as a post-transition metal.

What state is bismuth at room temperature?

At about 25 °C, bismuth is a solid. It melts at 271.55 °C.

How many valence electrons does bismuth have?

Bismuth has 5 electrons in its outer shell (shell pattern: 2, 8, 18, 32, 18, 5).

What is bismuth used for?

Key uses include: stomach remedies (bismuth subsalicylate); non-toxic replacement for lead in solder, shot and fishing weights; low-melting safety alloys for fire sprinklers.

Related elements

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