Gadolinium - Gd General Information Discovery Gadolinium was discovered by J.-C. Galissard de Marignac in 1880 in Geneva, Switzerland. Lecoq de Boisbaudran isolated the element in 1886. Appearance Gadolinium is a silvery-white metal with a lustrous sheen. Source In common with other lanthanides, gadolinium is found principally in the minerals monazite and bastnaesite, from which it can be commercially prepared by ion exchange and solvent extraction. It is also prepared by reduction of the anhydrous fluoride with calcium metal. Uses Gadolinium has useful properties in alloys. As little as 1% gadolinium has been found to improve the workability and resistance of iron and chromium alloys to high temperatures and oxidation. Its compounds are useful in magnetic resonance imaging (MRI), particularly in diagnosing cancerous tumours. It is also used in electronics and colour televisions. Biological Role Gadolinium has no known biological role, and has low toxicity. General Information Gadolinium reacts slowly with oxygen and water, and reacts with acids. It is relatively stable in dry air but tarnishes in moist air.

	Physical Information
	Atomic Number		64
	Relative Atomic Mass (12C=12.000)		157.25
	Melting Point/K		1586
	Boiling Point/K		3539
	Density/kg m-3		7900 (298K)
	Ground State Electron Configuration		[Xe]4f75d16s2
	Electron Affinity(M-M-)/kJ mol-1		-50

	Key Isotopes
	nuclide	152Gd	153Gd	154Gd	155Gd	156Gd
	atomic mass	151.9		153.9	154.9	155.9
	natural abundance	0.2%	0%	2.1%	14.8%	20.6%
	half-life	1.1x1014yrs	242 days	stable	stable	stable
	nuclide	157Gd	158Gd	160Gd
	atomic mass	156.9	157.9	159.9
	natural abundance	15.6%	24.8%	21.9%
	half-life	stable	stable	stable

Other Information
Enthalpy of Fusion/kJ mol-1		15.5
Enthalpy of Vaporisation/kJ mol-1		301
Oxidation States
Gd+2, Gd+3

	Ionisation Energies/kJ mol-1
	M - M+	592.5
	M+ - M2+	1167
	M2+ - M3+	1990
	M3+ - M4+	4250
	M4+ - M5+
	M5+ - M6+
	M6+ - M7+
	M7+ - M8+
	M8+ - M9+
	M9+ - M10+