మూస:పొలోనియం మూలకము

Polonium, 00Po
Polonium
Pronunciation/pəˈlniəm/ (-LOH-nee-əm)
Allotropesα, β
Appearancesilvery
Mass number[209]
Polonium in the periodic table
Hydrogen Helium
Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon
Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon
Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Iron Cobalt Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton
Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Silver Cadmium Indium Tin Antimony Tellurium Iodine Xenon
Caesium Barium Lanthanum Cerium Praseodymium Neodymium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium Lutetium Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gold Mercury (element) Thallium Lead Bismuth Polonium Astatine Radon
Francium Radium Actinium Thorium Protactinium Uranium Neptunium Plutonium Americium Curium Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Lawrencium Rutherfordium Dubnium Seaborgium Bohrium Hassium Meitnerium Darmstadtium Roentgenium Copernicium Ununtrium Flerovium Ununpentium Livermorium Ununseptium Ununoctium
Te

Po

Lv
bismuthpoloniumastatine
Groupమూస:Infobox element/symbol-to-group/format
Periodperiod 6
Block  p-block
Electron configuration[Xe] 4f14 5d10 6s2 6p4
Electrons per shell2, 8, 18, 32, 18, 6
Physical properties
Phase at STPsolid
Melting point527 K ​(254 °C, ​489 °F)
Boiling point1235 K ​(962 °C, ​1764 °F)
Density (near r.t.)alpha: 9.196 g/cm3
beta: 9.398 g/cm3
Heat of fusionca. 13 kJ/mol
Heat of vaporization102.91 kJ/mol
Molar heat capacity26.4 J/(mol·K)
Vapor pressure
P (Pa) 1 10 100 1 k 10 k 100 k
at T (K) (846) 1003 1236
Atomic properties
Oxidation states−2, +2, +4, +5,[1] +6 (an amphoteric oxide)
ElectronegativityPauling scale: 2.0
Ionization energies
  • 1st: 812.1 kJ/mol
Atomic radiusempirical: 168 pm
Covalent radius140±4 pm
Van der Waals radius197 pm
Color lines in a spectral range
Spectral lines of polonium
Other properties
Natural occurrencefrom decay
Crystal structurecubic
Cubic crystal structure for polonium
Thermal expansion23.5 µm/(m⋅K) (at 25 °C)
Thermal conductivity20 W/(m⋅K) (?)
Electrical resistivityα: 0.40 µΩ⋅m (at 0 °C)
Magnetic orderingnonmagnetic
CAS Number7440-08-6
History
Namingafter Polonia, Latin for Poland. Homeland of one of the discoverers
DiscoveryPierre Curie and Marie Curie (1898)
First isolationWilly Marckwald (1902)
Isotopes of polonium
Template:infobox polonium isotopes does not exist
 Category: Polonium
| references

References

  1. Thayer, John S. (2010). "Relativistic Effects and the Chemistry of the Heavier Main Group Elements". Relativistic Methods for Chemists. Challenges and Advances in Computational Chemistry and Physics. 10: 78. doi:10.1007/978-1-4020-9975-5_2. ISBN 978-1-4020-9974-8.
  2. Thayer, John S. (2010). Chemistry of heavier main group elements. p. 78. doi:10.1007/9781402099755_2.
  3. Boutin, Chad. "Polonium's Most Stable Isotope Gets Revised Half-Life Measurement". nist.gov. NIST Tech Beat. Retrieved 9 September 2014.