Europium
Pronunciation/jʊəˈrpiəm/ (yoor-OH-pee-əm)
Appearancesilvery white, with a pale yellow tint; but rarely seen without oxide discoloration
Standard atomic weight Ar, std(Eu)151.964(1)
Atomic number (Z)63
Groupgroup n/a
Periodperiod 6
Blockf-block
Element category  Lanthanide
Electron configuration[Xe] 4f7 6s2
Electrons per shell
2, 8, 18, 25, 8, 2
Phase at STPsolid
Melting point1099 K ​(826 °C, ​1519 °F)
Boiling point1802 K ​(1529 °C, ​2784 °F)
Density (near r.t.)5.264 g/cm3
when liquid (at m.p.)5.13 g/cm3
Heat of fusion9.21 kJ/mol
Heat of vaporization176 kJ/mol
Molar heat capacity27.66 J/(mol·K)
Oxidation states+1, +2, +3 (a mildly basic oxide)
ElectronegativityPauling scale: 1.2
Ionization energies
  • 1st: 547.1 kJ/mol
  • 2nd: 1085 kJ/mol
  • 3rd: 2404 kJ/mol
Atomic radiusempirical: 180 pm
Natural occurrenceprimordial
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 orderingparamagnetic
Magnetic susceptibility+34,000.0·10−6 cm3/mol
Young's modulus18.2 GPa
Shear modulus7.9 GPa
Bulk modulus8.3 GPa
Poisson ratio0.152
Vickers hardness165–200 MPa
CAS Number7440-53-1
Namingafter Europe
Discovery and first isolationEugène-Anatole Demarçay (1896, 1901)