Platinum

Platinum, 78Pt
Platinum
Pronunciation/ˈplætənəm/ (PLAT-ən-əm)
Appearancesilvery white
Standard atomic weight Ar°(Pt)
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
iridiumplatinumgold
Atomic number (Z)78
Groupgroup 10
Periodperiod 6
Block  d-block
Electron configuration[Xe] 4f14 5d9 6s1
Electrons per shell2, 8, 18, 32, 17, 1
Physical properties
Phase at STPsolid
Melting point2041.4 K ​(1768.3 °C, ​3214.9 °F)
Boiling point4098 K ​(3825 °C, ​6917 °F)
Density (near r.t.)21.45 g/cm3
when liquid (at m.p.)19.77 g/cm3
Heat of fusion22.17 kJ/mol
Heat of vaporization510 kJ/mol
Molar heat capacity25.86 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−3, −2, −1, 0, +1, +2, +3, +4, +5, +6 (a mildly basic oxide)
ElectronegativityPauling scale: 2.28
Ionization energies
  • 1st: 870 kJ/mol
  • 2nd: 1791 kJ/mol
Atomic radiusempirical: 139 pm
Covalent radius136±5 pm
Van der Waals radius175 pm
Color lines in a spectral range
Spectral lines of platinum
Other properties
Natural occurrenceprimordial
Crystal structureface-centered cubic (fcc)
Face-centered cubic crystal structure for platinum
Thermal expansion8.8 µm/(m⋅K) (at 25 °C)
Thermal conductivity71.6 W/(m⋅K)
Electrical resistivity105 nΩ⋅m (at 20 °C)
Magnetic orderingparamagnetic
Molar magnetic susceptibility+201.9 × 10−6 cm3/mol (290 K)[3]
Tensile strength125–240 MPa
Young's modulus168 GPa
Shear modulus61 GPa
Bulk modulus230 GPa
Speed of sound thin rod2800 m/s (at r.t.)
Poisson ratio0.38
Mohs hardness3.5
Vickers hardness400–550 MPa
Brinell hardness300–500 MPa
CAS Number7440-06-4
History
DiscoveryAntonio de Ulloa (1735)
Isotopes of platinum
Main isotopes[4] 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
| 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 "silver".[5][6]

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.[7]

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[8] 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.[9] Compounds containing platinum, such as cisplatin, oxaliplatin and carboplatin, are applied in chemotherapy against certain types of cancer.[10]

Pure platinum is currently less expensive than pure gold, having been so continuously since 2015, but has been twice as expensive or more, mostly prior to 2008.[11] In early 2021, the value of platinum ranged from US$1,055 to US$1,320 per troy ounce.[12]

  1. ^ "Standard Atomic Weights: Platinum". CIAAW. 2005.
  2. ^ Prohaska, Thomas; Irrgeher, Johanna; Benefield, Jacqueline; Böhlke, John K.; Chesson, Lesley A.; Coplen, Tyler B.; Ding, Tiping; Dunn, Philip J. H.; Gröning, Manfred; Holden, Norman E.; Meijer, Harro A. J. (4 May 2022). "Standard atomic weights of the elements 2021 (IUPAC Technical Report)". Pure and Applied Chemistry. doi:10.1515/pac-2019-0603. ISSN 1365-3075.
  3. ^ Weast, Robert (1984). CRC, Handbook of Chemistry and Physics. Boca Raton, Florida: Chemical Rubber Company Publishing. pp. E110. ISBN 0-8493-0464-4.
  4. ^ Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (2021). "The NUBASE2020 evaluation of nuclear properties" (PDF). Chinese Physics C. 45 (3): 030001. doi:10.1088/1674-1137/abddae.
  5. ^ "platinum (Pt)". Encyclopædia Britannica. Encyclopædia Britannica Inc. 2012. Archived from the original on 5 April 2012. Retrieved 24 April 2012.
  6. ^ Harper, Douglas. "platinum". Online Etymology Dictionary.
  7. ^ Hobson, Peter. "Currency shocks knock platinum to 10-year lows". Reuters. Retrieved 20 August 2018.
  8. ^ "Platinum in the Glass Industry". Johnson Matthey Technology Review.
  9. ^ "Chapter 6.11 Platinum" (PDF), Air Quality Guidelines (2nd ed.), WHO Regional Office for Europe, Copenhagen, Denmark, 2000, archived (PDF) from the original on 18 October 2012
  10. ^ Wheate, N. J.; Walker, S.; Craig, G. E.; Oun, R. (2010). "The status of platinum anticancer drugs in the clinic and in clinical trials" (PDF). Dalton Transactions. 39 (35): 8113–27. doi:10.1039/C0DT00292E. hdl:2123/14271. PMID 20593091.
  11. ^ "Platinum Prices vs Gold Prices".
  12. ^ "Live latinum Price Charts & Historical Data". APMEX. Retrieved 14 March 2021.

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