Europium

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Europium
63Eu
-

Eu

Am
samariumeuropiumgadolinium
Appearance
sillery white, but rarely seen wioot oxide discolouration
General properties
Name, seembol, nummer europium, Eu, 63
Pronunciation /jʊˈrpiəm/
ew-ROH-pee-əm
Element category lanthanide
Group, period, block n/a, 6, f
Staundart atomic wicht 151.964
Electron confeeguration [Xe] 4f7 6s2
2, 8, 18, 25, 8, 2
Electron shells of europium (2, 8, 18, 25, 8, 2)
History
Namin after Europe
Discovery Eugène-Anatole Demarçay (1896)
First isolation Eugène-Anatole Demarçay (1901)
Physical properties
Phase solid
Density (near r.t.) 5.264 g·cm−3
Liquid density at m.p. 5.13 g·cm−3
Meltin pynt 1099 K, 826 °C, 1519 °F
Boilin pynt 1802 K, 1529 °C, 2784 °F
Heat o fusion 9.21 kJ·mol−1
Heat o vaporization 176 kJ·mol−1
Molar heat capacity 27.66 J·mol−1·K−1
Vapor pressure
P (Pa) 1 10 100 1 k 10 k 100 k
at T (K) 863 957 1072 1234 1452 1796
Atomic properties
Oxidation states 3, 2, 1

(mildly basic oxide)

Electronegativity  ? 1.2 (Pauling scale)
Ionization energies 1st: 547.1 kJ·mol−1
2nd: 1085 kJ·mol−1
3rd: 2404 kJ·mol−1
Atomic radius 180 pm
Covalent radius 198±6 pm
Miscellanea
Crystal structure body-centered cubic
Europium has a body-centered cubic crystal structure
Magnetic orderin paramagnetic[1]
Electrical resistivity (r.t.) (poly) 0.900 µΩ·m
Thermal conductivity est. 13.9 W·m−1·K−1
Thermal expansion (r.t.) (poly)
35.0 µm/(m·K)
Young's modulus 18.2 GPa
Shear modulus 7.9 GPa
Bulk modulus 8.3 GPa
Poisson ratio 0.152
Vickers hairdness 167 MPa
CAS registry nummer 7440-53-1
Most stable isotopes
Main article: Isotopes o europium
iso NA hauf-life DM DE (MeV) DP
150Eu syn 36.9 y ε 2.261 150Sm
151Eu 47.8% 5×1018 y α 1.9644 147Pm
152Eu syn 13.516 y ε 1.874 152Sm
β 1.819 152Gd
153Eu 52.2% - (α) 0.2736 149Pm
Decay modes in parentheses are predicted, but have not yet been observed
· r

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 which readily oxidizes in air an watter. Bein a typical member o the lanthanide series, europium uisually assumes the oxidation state +3, but the oxidation state +2 is an aa common: 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.

References[eedit | eedit soorce]

  1. Magnetic susceptibility of the elements and inorganic compounds, in Lide, D. R., ed. (2005). CRC Handbook of Chemistry and Physics (86th ed.). Boca Raton (FL): CRC Press. ISBN 0-8493-0486-5.