మూస:ఆక్టీనియం మూలకము

Actinium, 00Ac
Actinium
Pronunciation/ækˈtɪniəm/ (ak-TIN-ee-əm)
Appearancesilvery-white, glowing with an eerie blue light;[1] sometimes with a golden cast[2]
Mass number[227]
Actinium 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
La

Ac

(Uqu)
radiumactiniumthorium
Groupమూస:Infobox element/symbol-to-group/format
Periodperiod 7
Block  f-block
Electron configuration[Rn] 6d1 7s2
Electrons per shell2, 8, 18, 32, 18, 9, 2
Physical properties
Phase at STPsolid
Melting point1500 K ​(1227 °C, ​2240 °F) (estimated)[2]
Boiling point3500±300 K ​(3200±300 °C, ​5800±500 °F) (extrapolated)[2]
Density (near r.t.)10 g/cm3
Heat of fusion14 kJ/mol
Heat of vaporization400 kJ/mol
Molar heat capacity27.2 J/(mol·K)
Atomic properties
Oxidation states+3 (a strongly basic oxide)
ElectronegativityPauling scale: 1.1
Ionization energies
  • 1st: 499 kJ/mol
  • 2nd: 1170 kJ/mol
Covalent radius215 pm
Color lines in a spectral range
Spectral lines of actinium
Other properties
Natural occurrencefrom decay
Crystal structureface-centered cubic (fcc)
Face-centered cubic crystal structure for actinium
Thermal conductivity12 W/(m⋅K)
CAS Number7440-34-8
History
Discovery and first isolationFriedrich Oskar Giesel (1902)
Isotopes of actinium
Template:infobox actinium isotopes does not exist
 Category: Actinium
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References

  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.