Polonium (Po or Element 84) is one of the radioactive elements discovered by Marie and Pierre Curie. This rare element has no stable isotopes. It's found in uranium ores and cigarette smoke and also occurs as a decay product of heavier elements. Although there aren't many applications for the element, it is used to generate heat from radioactive decay for space probes. The element is used as a neutron and alpha source and in anti-static devices. Polonium has also been used as a poison to commit assassinations. Although the position of element 84 on the periodic table would lead to categorization as a metalloid, its properties are those of a true metal.
Polonium Basic Facts
Symbol: Po
Atomic Number: 84
Discovery: Curie 1898
Atomic weight: [208.9824]
Electron configuration: [Xe] 4f14 5d10 6s2 6p4
Classification: semi-metal
Ground level: 3P2
Polonium Physical Data
Ionization potential: 8.414 ev
Physical form: Silvery metal
Melting point: 254°C
Boiling point: 962°C
Density: 9.20 g/cm3
Valence: 2, 4
References: Los Alamos National Laboratory (2001), Crescent Chemical Company (2001), Lange's Handbook of Chemistry (1952), CRC (2006)