Platinum - Pt General Information Discovery Platinum was discovered by South Americans and taken to Europe about 1750. The metal was used by pre-Columbian Indians. Appearance Platinum is a beautiful silvery-white metal, and is malleable and ductile. Source Platinum is found uncombined in alluvial deposits, and prepared commercially as a by-product of nickel refining from copper-nickel ores. Uses Platinum is used extensively for jewellery, wire and many valuable instruments including thermocouple elements. It is also used for electrical contacts, corrosion-resistance apparatus and in dentistry. In a finely divided state platinum absorbs large volumes of hydrogen and so is used as a catalyst in the petroleum cracking industry. Biological Role Platinum has no known biological role, and is non-toxic. General Information Platinum is not affected by air or water at any temperature. It is insoluble in hydrochloric and nitric acids, but dissolves when they are mixed to form aqua regia. The price of platinum fluctuates, but it can cost eight times as much as gold.

	Physical Information
	Atomic Number		78
	Relative Atomic Mass (12C=12.000)		195.08
	Melting Point/K		2045
	Boiling Point/K		4100
	Density/kg m-3		21450 (293K)
	Ground State Electron Configuration		[Xe]4f145d96s1
	Electron Affinity(M-M-)/kJ mol-1		-247

	Key Isotopes
	nuclide	190Pt	192Pt	194Pt	195Pt	196Pt
	atomic mass	189.96	191.96	193.96	194.96	195.96
	natural abundance	0.01%	0.79%	32.9%	33.8%	25.3%
	half-life	6.9x1011 yrs	1015 yrs	stable	stable	stable
	nuclide	197Pt	198Pt
	atomic mass		197.97
	natural abundance	0%	7.2%
	half-life	18 h	stable

Other Information
Enthalpy of Fusion/kJ mol-1		19.7
Enthalpy of Vaporisation/kJ mol-1		469
Oxidation States
main	Pt+4
others	Pt0, Pt+2, Pt+5, Pt+6

	Ionisation Energies/kJ mol-1
	M - M+	870
	M+ - M2+	1791
	M2+ - M3+	2800
	M3+ - M4+	3900
	M4+ - M5+	5300
	M5+ - M6+	7200
	M6+ - M7+	8900
	M7+ - M8+	10500
	M8+ - M9+	12300
	M9+ - M10+	14100