About

Bismuth is a brittle, silvery-white metal with a distinct pinkish tinge due to a surface oxide layer. It is unusually non-toxic for a heavy metal and is used in stomach-soothing remedies like Pepto-Bismol. Its alloys have very low melting points and are used as lead-substitutes in solder, fuses, and fire sprinklers. It is technically radioactive but its half-life is billions of times the age of the universe.

Atomic Properties

Atomic Number83

Atomic Weight208.98 u

Neutrons (common)126

Electron Configuration[Xe] 4f¹⁴ 5d¹⁰ 6s² 6p³

Full Configuration1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f¹⁴ 5s² 5p⁶ 5d¹⁰ 6s² 6p³

Electrons per Shell2, 8, 18, 32, 18, 5

Electronegativity2.02

Electron Affinity90.924 kJ/mol

Oxidation States+5, +3

Covalent Radius151 pm

Van der Waals Radius207 pm

Ionic Radius103 pm

Periodic Table Position

Group15

Period6

BlockP

Chemical SeriesPost-transition metals

Physical Properties

State at STPsolid

Appearancehard, brittle, silvery-white metal with a pinkish tint

Crystal Structurerhombohedral

Magnetic Orderingdiamagnetic

Speed of Sound1,790 m/s

Poisson Ratio0.33

Thermal Properties

Melting Point544.7 K

Boiling Point1,837 K

Triple Point544.7 K

Thermal Expansion0 1/K

Thermal Conductivity7.97 W/(m·K)

Specific Heat0.122 J/(g·K)

Molar Heat25.52 J/(mol·K)

Heat of Fusion11.3 kJ/mol

Heat of Vaporization179 kJ/mol

Abundance

In Earth's Crust0.009 ppm

In Ocean0 ppm

In Solar System0 ppm

In Universe0.001 ppm

Discovery

Discovered byClaude François Geoffroy

Discovery Year1,753

Occurrenceprimordial

CAS Number7440-69-9

Electron Configuration

Energy

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Isotopes of Bismuth

Symbol ▲	Mass (u) ▲	Abundance ▲	Half-life ▲	Decay Mode ▲
²⁰⁵Bi	204.978480	—	14.91 d	Electron Capture
²⁰⁶Bi	205.978480	—	6.243 d	Electron Capture
²⁰⁷Bi	206.978470	—	31.22 y	Electron Capture
²⁰⁹Bi	208.980390	100%	20.1 Ey	Alpha Decay

Interactive Visualization

Explore the 3D Bohr model of Bismuth in our interactive viewer.

View 3D Model of Bismuth