Polonium (84)

Polonium has more isotopes than any other element, all of which are radioactive. Polonium dissolves readily in dilute acids, but is only slightly soluble in alkalis.

Weight for weight it is about 2.5 x 1011 times as toxic as hydrocyanic acid (HCN). Polonium has been found in tobacco as a contaminant and in uranium ores.

•Name: Polonium
•Symbol: Po
•Atomic number: 84
•Atomic weight: [ 209 ]
•Standard state: solid at 298 K
•CAS Registry ID: 7440-08-6
•Group in periodic table: 16
•Group name: Chalcogen
•Period in periodic table: 6
•Block in periodic table: p-block
•Color: silvery
•Classification: Metallic

 Historical information

Polonium was the first element discovered by Marie Curie at 1898 in France, and was named after "Poland" - her birthplace (maiden name Sklodowska). Polonium was the first element discovered by Marie Sklodowska Curie in 1898, while seeking the cause of radioactivity of pitchblende from Joachimsthal, Bohemia. It required several tonnes of pitchblende to produce very small amounts of polonium.

 Physical properties

•Melting point: 527 [or 254 °C (489 °F)] K

•Boiling point: 1235 [or 962 °C (1764 °F)] K

•Density of solid: 9196 kg m-3

 

Orbital properties

•Ground state electron configuration: [Xe].4f14.5d10.6s2.6p4

•Shell structure: 2.8.18.32.18.6

 Polonium is radioactive and excessivley rare in nature. It is made in very small qunatities through a nuclear reaction of bismuth. Neutron irradiation of 209bismuth (atomic number 83) gives 210polonium (atomic number 84).

209Bi + 1n → 210Po + e-

Metallic polonium can be fractionally distilled from the bismuth or electrodeposited onto a metal surface such as silver