Europium - Eu General Information Discovery Europium was discovered by E.A. Demaraçy in 1901 in Paris, France. The pure metal has only recently been prepared. Appearance Europium is a soft, silvery-white metal. Source In common with other lanthanides, europium is found principally in the minerals monazite and bastnaesite, from which it can be prepared. However, the usual method of preparation is by heating europium(Ill) oxide with an excess of lanthanum under vacuum. Uses Europium can absorb more neutrons per atom than any other element, making it valuable in control rods for nuclear reactors. Europium-doped plastic has been used as a laser material. Otherwise this element is very little used. Biological Role Europium has no known biological role, and has low toxicity. General Information Europium is the costliest and one of the rarest of the lanthanides. It is as soft as lead and ductile, and is the most reactive of the lanthanide metals, reacting rapidly with water and air.

	Physical Information
	Atomic Number		63
	Relative Atomic Mass (12C=12.000)		151.97
	Melting Point/K		1095
	Boiling Point/K		1870
	Density/kg m-3		5243 (293K)
	Ground State Electron Configuration		[Xe]4f76s2
	Electron Affinity(M-M-)/kJ mol-1		-50

	Key Isotopes
	nuclide	151Eu	152Eu	153Eu
	atomic mass	150.9		152.9
	natural abundance	47.8%	0%	52.2%
	half-life	stable	12.7 yrs	stable

Other Information
Enthalpy of Fusion/kJ mol-1		10.5
Enthalpy of Vaporisation/kJ mol-1		176
Oxidation States
main	Eu+3
others	Eu+2

	Ionisation Energies/kJ mol-1
	M - M+	546.7
	M+ - M2+	1085
	M2+ - M3+	2404
	M3+ - M4+	4110
	M4+ - M5+
	M5+ - M6+
	M6+ - M7+
	M7+ - M8+
	M8+ - M9+
	M9+ - M10+