84
Po
Polonium
210
Polonium (Po)
MetalloidGroup 16Period 6p-block-blockRadioactive
Polonium is a chemical element with symbol Po and atomic number 84, discovered in 1898 by Marie Curie and Pierre Curie. A rare and highly radioactive element with no stable isotopes, polonium is chemically similar to bismuth and tellurium, and it occurs in uranium ores. Applications of polonium are few.
Latin name: Polonium
Atomic Number
84
Atomic Mass
210 g/mol
Phase (STP)
Solid
Electron Config.
[Xe] 4f¹⁴ 5d¹⁰ 6s² 6p⁴
General
SymbolPo
Atomic Number84
Atomic Mass210 g/mol
CategoryMetalloid
Group16
Period6
Blockp-block
Electron Configuration[Xe] 4f¹⁴ 5d¹⁰ 6s² 6p⁴
Valence Electrons6
Coloursilvery-gray metallic (rare, radioactive)
Appearancesilvery
Physical Properties
Phase (STP)Solid
Density9.32 g/cm³
Melting Point253.85°C · 488.93°F · 527.00 K
Boiling Point961.85°C · 1763.33°F · 1235.00 K
Atomic Properties
Atomic Radius197 pm
Electronegativity2 Pauling
Ionization Energy812 kJ/mol
Oxidation States+4, +2, -2
Ion ChargePo2+/Po4+/Po2-
Thermodynamic
Molar Heat26.4 J/(mol·K)
Crystal Structure
Crystal Structuresimple cubic (reported)
Nuclear & Hazards
RadioactiveYes
Half-life138.376 days (Po-210, common isotope)
Abundance
In Universe0.00000001%
In Earth's Crust0.00000001%
Discovery & History
Discovery Year1898
Discovered ByMarie Curie, Pierre Curie
Country of DiscoveryFrance/Poland
Isotopes of Polonium
| Isotope | Abundance | Half-life | Decay |
|---|---|---|---|
| Po-208 | — | 2.898 years | α |
| Po-209 | — | 125.2 years | α |
| Po-210 | — | 138.376 days | α |