Polonium

Koushik 26/06/2026 19:58:09 Updated 26/06/2026 19:58:09

Property	Value
Atomic Number	84
Element	Polonium
Symbol	Po
Atomic Mass	[209] (most stable isotope)
Number of Neutrons	125 (Polonium-209)
Number of Protons	84
Number of Electrons	84
Period	6
Group	16
Phase	Solid
Radioactive	Yes
Natural	Yes (trace amounts in uranium ores)
Metal	Yes
Nonmetal	No
Metalloid	No
Type	Post-transition Metal
Atomic Radius	135 pm (estimated)
Electronegativity	2.00 (Pauling scale)
First Ionization Energy	8.417 eV
Density	9.32 g/cm³
Melting Point	254 °C
Boiling Point	962 °C
Number of Isotopes	No stable isotopes (Po-209, Po-210 most notable)
Discoverer	Marie Curie, Pierre Curie
Year	1898
Specific Heat	— (data not well established)
Number of Shells	6
Number of Valence Electrons	6