Symbol	Po
Atomic number	84
Group	16 (Oxygen group)
Period	6
Block	p
Classification	Post-Transition Metal

Appearance	Silvery
Color	Silver

Number of protons	84 p+
Number of neutrons	125 n0
Number of electrons	84 e-

From Wikipedia, the free encyclopediaPolonium 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.

Phase at STP	Solid
Density	9.196 g/cm3
Atomic weight	209 u

Melting point	527 K 253.85 °C 488.93 °F
Boiling point	1235 K 961.85 °C 1763.33 °F
Heat of vaporization	120 kJ/mol

Electronegativity (Pauling Scale)	2
Electron affinity	136 kJ/mol
Oxidation states	−2, +2, +4, +5, +6 (an amphoteric oxide)
Ionization energies	812.1 kJ/mol

Electron configuration Shorthand configuration	[Xe] 4f14 5d10 6s2 6p4
Electron configuration Full configuration	1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d10 6s2 6p4
Electron configuration chart	1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d10 6s2 6p4
Electrons per shell	2, 8, 18, 32, 18, 6
Valence electrons	6
Valency electrons	2,4,6
Bohr model	Figure: Shell diagram of Polonium (Po) atom.
Orbital Diagram 1s 2s 2p 3s 3p 3d 4s 4p 4d 4f 5s 5p 5d 6s 6p

Discovery	Pierre Curie, Marie Curie (1898)
First isolation	Willy Marckwald (1902)
Named by	Pierre Curie, Marie Curie
Discovery of polonium Tentatively called "radium F", polonium was discovered by Marie and Pierre Curie in July 1898, when it was extracted from the uranium ore pitchblende and identified solely by its strong radioactivity: it was the first element to be so discovered. It was named after Marie Curie's native land of Poland (Latin: Polonia). Poland at the time was under Russian, German, and Austro-Hungarian partition, and did not exist as an independent country. It was Curie's hope that naming the element after her native land would publicize its lack of independence. Polonium may be the first element named to highlight a political controversy. German scientist Willy Marckwald successfully isolated 3 milligrams of polonium in 1902, though at the time he believed it was a new element, which he dubbed "radio-tellurium", and it was not until 1905 that it was demonstrated to be the same as polonium.

CAS Number	7440-08-6
ChemSpider ID	4886482
EC number	231-118-2
PubChem CID Number	6328143