Americium

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Americium,  95Am
Americium microscope.jpg
General properties
Appearancesillery white
Mass nummer243 (most stable isotope)
Americium 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
Eu

Am

(Uqs)
plutoniumamericiumcurium
Atomic nummer (Z)95
Groupgroup n/a
Periodperiod 7
Element category  actinide
Blockf-block
Electron confeeguration[Rn] 5f7 7s2
Electrons per shell
2, 8, 18, 32, 25, 8, 2
Pheesical properties
Phase (at STP)solit
Meltin pynt1449 K ​(1176 °C, ​2149 °F)
Bylin pynt2880 K ​(2607 °C, ​4725 °F) (calculatit)
Density (near r.t.)12 g/cm3
Heat o fusion14.39 kJ/mol
Molar heat capacity62.7 J/(mol·K)
Vapour pressur
P (Pa) 1 10 100 1 k 10 k 100 k
at T (K) 1239 1356
Atomic properties
Oxidation states8, 7, 6, 5, 4, 3, 2 ​(an amphoteric oxide)
ElectronegativityPauling scale: 1.3
Ionisation energies
  • 1st: 578 kJ/mol
Atomic radiusempirical: 173 pm
Covalent radius180±6 pm
Coloyr lines in a spectral range
Spectral lines o Americium
Miscellanea
Creestal structur ​dooble hexagonal close packed
[[File:dooble hexagonal close packed|50px|alt=Dooble hexagonal close packed creestal structur for americium|Dooble hexagonal close packed creestal structur for americium]]
Thermal conductivity10 W/(m·K)
Electrical resistivity0.69 µΩ·m[1]
Magnetic orderinparamagnetic
CAS Nummer7440-35-9
History
Naminefter the Americas
DiskiveryGlenn T. Seaborg, Ralph A. James, Leon O. Morgan, Albert Ghiorso (1944)
Main isotopes o americium
Iso­tope Abun­dance Hauf-life (t1/2) Decay mode Pro­duct
241Am syn 432.2 y SF
α 237Np 242mAm syn 141 y IT 242Am
α 238Np
SF
243Am syn 7370 y SF
α 239Np
| references | in Wikidata

Americium is a radioactive transuranic chemical element wi seembol Am an atomic nummer 95.

References[eedit | eedit soorce]

  1. Muller, W.; Schenkel, R.; Schmidt, H. E.; Spirlet, J. C.; McElroy, D. L.; Hall, R. O. A.; Mortimer, M. J. (1978). "The electrical resistivity and specific heat of americium metal". Journal of Low Temperature Physics. 30 (5–6): 561. Bibcode:1978JLTP...30..561M. doi:10.1007/BF00116197.