Actinium

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Actinium, 89Ac
Actinium
Pronunciation/ækˈtɪniəm/ (ak-TIN-nee-əm)
Appearancesillery-white, glowin wi an eerie blue licht;[1] sometimes with a golden cast[2]
Mass number[227]
Actinium 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
La

Ac

(Uqu)
radiumactiniumthorium
Atomic nummer (Z)89
Groupgroup 3
Periodperiod 7
Blockf-block
Element category  Actinide
Electron confeeguration[Rn] 6d1 7s2
Electrons per shell2, 8, 18, 32, 18, 9, 2
Pheesical properties
Phase at STPsolit
Meltin pynt1500 K ​(1227 °C, ​2240 °F) (estimatit)[2]
Bylin pynt3500±300 K ​(3200±300 °C, ​5800±500 °F) (extrapolatit)[2]
Density (near r.t.)10 g/cm3
Heat o fusion14 kJ/mol
Heat o vapourisation400 kJ/mol
Molar heat capacity27.2 J/(mol·K)
Atomic properties
Oxidation states+2, +3 strangly basic
ElectronegativityPauling scale: 1.1
Ionisation energies
  • 1st: 499 kJ/mol
  • 2nd: 1170 kJ/mol
Covalent radius215 pm
Colour lines in a spectral range
Spectral lines o actinium
Ither properties
Creestal structur ​face-centred cubic
[[File:face-centred cubic|frameless|alt=Face-centred cubic creestal structur for actinium|upright=0.23|Face-centred cubic creestal structur for actinium]]
Thermal conductivity12 W/(m·K)
CAS Nummer7440-34-8
History
Diskivery an first isolationFriedrich Oskar Giesel (1902)
Main isotopes o actinium
Iso­tope Abun­dance Hauf-life (t1/2) Decay mode Pro­duct
225Ac trace 10 d α 221Fr 226Ac syn 29.37 h β 226Th
ε 226Ra
α 222Fr
227Ac trace 21.772 y β 227Th
α 223Fr
| references

Actinium is a radioactive chemical element wi seembol Ac (nae tae be confused wi the abbreviation for an acetyl group) an atomic nummer 89, which wis discovered in 1899.

References[eedit | eedit soorce]

  1. Wall, Greg (8 September 2003). "C&EN: It's Elemental: The Periodic Table - Actinium". C&EN: It's Elemental: The Periodic Table. Chemical and Engineering News. Retrieved 2 June 2011.
  2. 2.0 2.1 2.2 Kirby, Harold W.; Morss, Lester R. (2006). "Actinium". The Chemistry of the Actinide and Transactinide Elements. p. 18. doi:10.1007/1-4020-3598-5_2. ISBN 978-1-4020-3555-5.