Po

Polonium

Identification

CAS Number: 7440-08-6

Discovery Year: 1898

Discoverer: Pierre and Marie Curie

Discovery Location: France

Properties

Atomic Mass: 209 →Density: 9.2 g/cm³ →

Crust Abundance: 2e-10 mg/kg

Crystal Structure: SC

Atomic Dimensions

Atomic Radius: 190 pm →

Atomic Radius (Rahm): 250 pm

Covalent Radius: 140 pm →

Van der Waals Radius: 197 pm

Atomic Volume: 22.7 cm³/mol

Lattice Constant: 3.35 Å

Thermodynamics

Melting Point: 527 K →Boiling Point: 1235 K →Specific Heat: 0.125 J/(g·K) →Heat of Fusion: 10 kJ/mol →Heat of Vaporization: 102.9 kJ/mol →

Electronic Structure

Electron Config: [Xe] 4f14 5d10 6s2 6p4

Block: p

Period: 6 →Group: 16 →Electronegativity: 2 →Electron Affinity: 1.9 eV →

Oxidation States: +2, +4, +6

Abundance & Geochemistry

Crust Abundance: 2e-10 mg/kg

Sea Abundance: 1.5e-14 mg/L

Geochemical Class: U/Th decay series

Goldschmidt Class: synthetic

About

Rare radioactive metallic element, belongs to group 16 of the periodic table. Over 30 known isotopes exist, the most of all elements. Po-209 has a half-life of 103 years. Possible uses in heating spacecraft. Discovered by Marie Curie in 1898 in a sample of pitchblende.

Isotopes

Po-208 208 ☢ 2.90 a

Po-209 209 ☢ 102 a

Po-210 210 ☢ 138 d