About

Polonium is a rare and highly radioactive metalloid discovered by Marie Curie, who named it after her native Poland. It is intensely toxic, even in minute amounts, due to its alpha radiation. It has been used as a compact source of alpha particles in scientific research and, controversially, as a poison. It is also used in devices to eliminate static electricity in industrial settings.

Atomic Properties

Atomic Number84

Atomic Weight208.982 u

Neutrons (common)125

Electron Configuration[Xe] 4f¹⁴ 5d¹⁰ 6s² 6p⁴

Full Configuration1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f¹⁴ 5s² 5p⁶ 5d¹⁰ 6s² 6p⁴

Electrons per Shell2, 8, 18, 32, 18, 6

Electronegativity2

Electron Affinity183.3 kJ/mol

Oxidation States+6, +4, +2, -2

Covalent Radius140 pm

Van der Waals Radius197 pm

Ionic Radius94 pm

Periodic Table Position

Group16

Period6

BlockP

Chemical SeriesMetalloids

Physical Properties

State at STPsolid

Appearancesilvery-gray, radioactive metal

Crystal Structuresimple cubic

Magnetic Orderingdiamagnetic

Thermal Properties

Melting Point527 K

Boiling Point1,235 K

Thermal Expansion0 1/K

Thermal Conductivity20 W/(m·K)

Specific Heat0.126 J/(g·K)

Molar Heat26.33 J/(mol·K)

Heat of Fusion13 kJ/mol

Heat of Vaporization102.9 kJ/mol

Abundance

In Earth's Crust0 ppm

Discovery

Discovered byMarie Curie, Pierre Curie

Discovery Year1,898

Occurrencefrom_decay

CAS Number7440-08-6

Electron Configuration

Energy

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Isotopes of Polonium

Symbol ▲	Mass (u) ▲	Abundance ▲	Half-life ▲	Decay Mode ▲
²⁰⁸Po	207.981240	—	2.898 y	Alpha Decay, Electron Capture
²⁰⁹Po	208.982430	—	124 y	Alpha Decay, Electron Capture
²¹⁰Po	209.982870	Trace	138.376 d	Alpha Decay

Interactive Visualization

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

View 3D Model of Polonium