Promethium

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Promethium, 61Pm
Promethium
Pronunciation/prˈmθiəm/ (proh-MEE-thee-əm)
Appearancemetallic
Mass number[145]
Promethium in the periodic cairt
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 Airn Cobalt Nickel Capper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton
Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Siller (element) 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 Gowd Mercur (element) Thallium Leid (element) 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
-

Pm

Np
neodymiumpromethiumsamarium
Atomic nummer (Z)61
Groupgroup n/a
Periodperiod 6
Blockf-block
Element category  Lanthanide
Electron confeeguration[Xe] 4f5 6s2
Electrons per shell2, 8, 18, 23, 8, 2
Pheesical properties
Phase at STPsolit
Meltin pynt1315 K ​(1042 °C, ​1908 °F)
Bylin pynt3273 K ​(3000 °C, ​5432 °F)
Density (near r.t.)7.26 g/cm3
Heat o fusion7.13 kJ/mol
Heat o vapourisation289 kJ/mol
Atomic properties
Oxidation states+2, +3 (a mildly basic oxide)
ElectronegativityPauling scale: ? 1.13
Atomic radiusempirical: 183 pm
Covalent radius199 pm
Colour lines in a spectral range
Spectral lines o promethium
Ither properties
Naitural occurrencefrom decay
Creestal structurhexagonal
Hexagonal creestal structur for promethium
Thermal expansion(r.t.) (α, poly)
est. 11 µm/(m·K)
Thermal conductivity17.9 W/(m·K)
Electrical resistivity(r.t.) est. 0.75 µ Ω·m
Magnetic orderinparamagnetic[1]
Young's modulus(α form) est. 46 GPa
Shear modulus(α form) est. 18 GPa
Bulk modulus(α form) est. 33 GPa
Poisson ratio(α form) est. 0.28
CAS Nummer7440-12-2
History
DiskiveryChien Shiung Wu, Emilio Segrè, Hans Bethe (1942)
First isolationCharles D. Coryell, Jacob A. Marinsky, Lawrence E. Glendenin, Harold G. Richter (1945)
Named byGrace Mary Coryell (1945)
Main isotopes o promethium
Iso­tope Abun­dance Hauf-life (t1/2) Decay mode Pro­duct
145Pm syn 17.7 y ε 145Nd
146Pm syn 5.53 y ε 146Nd
β 146Sm
147Pm trace 2.6234 y β 147Sm
| references

Promethium, oreeginally prometheum, is a chemical element wi the seembol Pm an atomic nummer 61. Aw o its isotopes are radioactive; it is ane o anly twa sic elements that are follaed in the periodic cairt bi elements wi stable furms, a distinction shared wi technetium. Chemically, promethium is a lanthanide, which furms sauts when combined wi ither elements. Promethium shaws anly ane stable oxidation state o +3; houiver, a few +2 compoonds mey exist.

References[eedit | eedit soorce]

  1. Magnetic susceptibility of the elements and inorganic compounds, in Handbook of Chemistry and Physics 81st edition, CRC press.