Europium is a chemical element wi the seembol Eu an atomic nummer 63. It is named efter the continent Europe. It is a moderately haird, sillery metal whilk readily oxidizes in air an watter. Bein a teepical member o the lanthanide series, europium uisually assumes the oxidation state +3, but the oxidation state +2 is common an aa: aw europium compoonds wi oxidation state +2 are slichtly reducing. Europium haes na signeeficant biological role an is relatively non-toxic compared tae ither hivy metals. Maist applications o europium exploit the phosphorescence o europium compoonds.

Europium, 63Eu
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Europium
Pronunciation/j[unsupported input]piəm/ (yoor-OH-pee-əm)
Appearancesillrry white, wi a pale yellsr tint;[1] but rarely seen without oxide discoloration
Standard atomic weight Ar, std(Eu)151.964(1)[2]
Europium 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
samariumeuropiumgadolinium
Atomic nummer (Z)63
Groupgroup n/a
Periodperiod 6
Blockf-block
Element category  Lanthanide
Electron confeeguration[Xe] 4f7 6s2
Electrons per shell2, 8, 18, 25, 8, 2
Pheesical properties
Phase at STPsolid
Meltin pynt1099 K ​(826 °C, ​1519 °F)
Bylin pynt1802 K ​(1529 °C, ​2784 °F)
Density (near r.t.)5.264 g/cm3
when liquid (at m.p.)5.13 g/cm3
Heat o fusion9.21 kJ/mol
Heat o vapourisation176 kJ/mol
Molar heat capacity27.66 J/(mol·K)
Vapour pressur
P (Pa) 1 10 100 1 k 10 k 100 k
at T (K) 863 957 1072 1234 1452 1796
Atomic properties
Oxidation states+1, +2, +3 (a mildly basic oxide)
ElectronegativityPauling scale: 1.2
Ionisation energies
  • 1st: 547.1 kJ/mol
  • 2nd: 1085 kJ/mol
  • 3rd: 2404 kJ/mol
Atomic radiusempirical: 180 pm
Covalent radius198±6 pm
Colour lines in a spectral range
Colour lines in a spectral range
Spectral lines o europium
Ither properties
Naitural occurrenceprimordial
Creestal structur ​bouk-centred cubic
[[File:bouk-centred cubic|frameless|alt=Bouk-centred cubic creestal structur for europium|upright=0.23|Bouk-centred cubic creestal structur for europium]]
Thermal expansionpoly: 35.0 µm/(m·K) (at r.t.)
Thermal conductivityest. 13.9 W/(m·K)
Electrical resistivitypoly: 0.900 µΩ·m (at r.t.)
Magnetic orderinparamagnetic[3]
Magnetic susceptibility+34,000.0·10−6 cm3/mol[4]
Young's modulus18.2 GPa
Shear modulus7.9 GPa
Bulk modulus8.3 GPa
Poisson ratio0.152
Vickers haurdness165–200 MPa
CAS Nummer7440-53-1
History
Naminefter Europe
Diskivery an first isolationEugène-Anatole Demarçay (1896, 1901)
Main isotopes o europium
Iso­tope Abun­dance Hauf-life (t1/2) Decay mode Pro­duct
150Eu syn 36.9 y ε 150Sm
151Eu 47.8% 5×1018 y α 147Pm
152Eu syn 13.54 y ε 152Sm
β 152Gd
153Eu 52.2% stable
154Eu syn 8.59 y β 154Gd
155Eu syn 4.76 y β 155Gd
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References

eedit
  1. Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth–Heinemann. p. 112. ISBN 0080379419.
  2. Meija, Juris; et al. (2016). "Atomic weights of the elements 2013 (IUPAC Technical Report)". Pure and Applied Chemistry. 88 (3): 265–91. doi:10.1515/pac-2015-0305.
  3. Lide, D. R., ed. (2005). "Magnetic susceptibility of the elements and inorganic compounds". CRC Handbook of Chemistry and Physics (PDF) (86th ed.). Boca Raton (FL): CRC Press. ISBN 0-8493-0486-5.
  4. Weast, Robert (1984). CRC, Handbook of Chemistry and Physics. Boca Raton, Florida: Chemical Rubber Company Publishing. pp. E110. ISBN 0-8493-0464-4.