Platinum

Platinum, ₇₈Pt

Platinum
Pronunciation	/ˈplætənəm/ ​(PLAT-ən-əm)
Appearance	silvery white
Standard atomic weight Ar°(Pt)
	195.084±0.009[1] 195.08±0.02 (abridged)[2]
Platinum in the periodic table
Hydrogen Helium Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon Sodium Magnesium Aluminium Silicon Phosphorus Sulfur Chlorine Argon Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Iron Cobalt Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Silver Cadmium Indium Tin Antimony Tellurium Iodine Xenon Caesium Barium Lanthanum Cerium Praseodymium Neodymium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium Lutetium Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gold Mercury (element) Thallium Lead Bismuth Polonium Astatine Radon Francium Radium Actinium Thorium Protactinium Uranium Neptunium Plutonium Americium Curium Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Lawrencium Rutherfordium Dubnium Seaborgium Bohrium Hassium Meitnerium Darmstadtium Roentgenium Copernicium Nihonium Flerovium Moscovium Livermorium Tennessine Oganesson Pd ↑ Pt ↓ Ds iridium ← platinum → gold
Atomic number (Z)	78
Group	group 10
Period	period 6
Block	d-block
Electron configuration	[Xe] 4f14 5d9 6s1
Electrons per shell	2, 8, 18, 32, 17, 1
Physical properties
Phase at STP	solid
Melting point	2041.4 K ​(1768.3 °C, ​3214.9 °F)
Boiling point	4098 K ​(3825 °C, ​6917 °F)
Density (at 20° C)	21.452 g/cm3 [3]
when liquid (at m.p.)	19.77 g/cm3
Heat of fusion	22.17 kJ/mol
Heat of vaporization	510 kJ/mol
Molar heat capacity	25.86 J/(mol·K)
Vapor pressure P (Pa) 1 10 100 1 k 10 k 100 k at T (K) 2330 (2550) 2815 3143 3556 4094
Atomic properties
Oxidation states	common: +2, +4 −3,? −2,? −1,? 0,? +1,? +3,? +5,[4] +6[4]
Electronegativity	Pauling scale: 2.28
Ionization energies	1st: 870 kJ/mol 2nd: 1791 kJ/mol
Atomic radius	empirical: 139 pm
Covalent radius	136±5 pm
Van der Waals radius	175 pm
Spectral lines of platinum
Other properties
Natural occurrence	primordial
Crystal structure	​face-centered cubic (fcc) (cF4)
Lattice constant	a = 392.36 pm (at 20 °C)[3]
Thermal expansion	8.93×10−6/K (at 20 °C)[3]
Thermal conductivity	71.6 W/(m⋅K)
Electrical resistivity	105 nΩ⋅m (at 20 °C)
Magnetic ordering	paramagnetic
Molar magnetic susceptibility	+201.9 × 10−6 cm3/mol (290 K)[5]
Tensile strength	125–240 MPa
Young's modulus	168 GPa
Shear modulus	61 GPa
Bulk modulus	230 GPa
Speed of sound thin rod	2800 m/s (at r.t.)
Poisson ratio	0.38
Mohs hardness	3.5
Vickers hardness	400–550 MPa
Brinell hardness	300–500 MPa
CAS Number	7440-06-4
History
Discovery	Antonio de Ulloa (1735)
Isotopes of platinum v e
Main isotopes[6] Decay abun­dance half-life (t1/2) mode pro­duct 190Pt 0.0120% 4.83×1011 y α 186Os 192Pt 0.782% stable 193Pt synth 50 y ε 193Ir 194Pt 32.9% stable 195Pt 33.8% stable 196Pt 25.2% stable 198Pt 7.36% stable
Category: Platinum view talk edit | references

Platinum is a chemical element; it has symbol Pt and atomic number 78. It is a dense, malleable, ductile, highly unreactive, precious, silverish-white transition metal. Its name originates from Spanish platina, a diminutive of plata "little silver".^[7][8]

Platinum is a member of the platinum group of elements and group 10 of the periodic table of elements. It has six naturally occurring isotopes. It is one of the rarer elements in Earth's crust, with an average abundance of approximately 5 μg/kg. It occurs in some nickel and copper ores along with some native deposits, mostly in South Africa, which accounts for ~80% of the world production. Because of its scarcity in Earth's crust, only a few hundred tonnes are produced annually, and given its important uses, it is highly valuable and is a major precious metal commodity.^[9]

Platinum is one of the least reactive metals. It has remarkable resistance to corrosion, even at high temperatures, and is therefore considered a noble metal. Consequently, platinum is often found chemically uncombined as native platinum. Because it occurs naturally in the alluvial sands of various rivers, it was first used by pre-Columbian South American natives to produce artifacts. It was referenced in European writings as early as the 16th century, but it was not until Antonio de Ulloa published a report on a new metal of Colombian origin in 1748 that it began to be investigated by scientists.

Platinum is used in catalytic converters, laboratory equipment, electrical contacts and electrodes, platinum resistance thermometers, dentistry equipment, and jewelry. Platinum is used in the glass industry^[10] to manipulate molten glass, which does not "wet" platinum. As a heavy metal, it leads to health problems upon exposure to its salts; but due to its corrosion resistance, metallic platinum has not been linked to adverse health effects.^[11] Compounds containing platinum, such as cisplatin, oxaliplatin and carboplatin, are applied in chemotherapy against certain types of cancer.^[12]