Platinum

Platinum, ₇₈Pt

Platinum
Pronunciation	/ˈplætɪnəm/ ​(PLAT-in-ǝm)
Appearance	grayish white
Standard atomic weight Ar, std(Pt)	7002195084000000000♠195.084(9)[1]
Platinum in the periodic cairt
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 Airn Cobalt Nickel Capper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Siller (element) 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 Gowd Mercur (element) Thallium Leid (element) 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 Ununtrium Flerovium Ununpentium Livermorium Ununseptium Ununoctium Pd ↑ Pt ↓ Ds iridium ← platinum → gowd
Atomic nummer (Z)	78
Group	group 10
Period	period 6
Block	d-block
Element category	Transeetion metal
Electron confeeguration	[Xe] 4f14 5d9 6s1
Electrons per shell	2, 8, 18, 32, 17, 1
Pheesical properties
Phase at STP	solit
Meltin pynt	2041.4 K ​(1768.3 °C, ​3214.9 °F)
Bylin pynt	4098 K ​(3825 °C, ​6917 °F)
Density (near r.t.)	21.45 g/cm3
when liquid (at m.p.)	19.77 g/cm3
Heat o fusion	22.17 kJ/mol
Heat o vapourisation	469 kJ/mol
Molar heat capacity	25.86 J/(mol·K)
Vapour pressur 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)
Electronegativity	Pauling scale: 2.28
Atomic radius	empirical: 139 pm
Covalent radius	136±5 pm
Van der Waals radius	175 pm
Spectral lines o platinum
Ither properties
Naitural occurrence	primordial
Creestal structur	​face-centred cubic (fcc)
Speed o soond thin rod	2800 m/s (at r.t.)
Thermal expansion	8.8 µm/(m·K) (at 25 °C)
Thermal conductivity	71.6 W/(m·K)
Electrical resistivity	105 n Ω·m (at 20 °C)
Magnetic orderin	paramagnetic
Young's modulus	168 GPa
Shear modulus	61 GPa
Bulk modulus	230 GPa
Poisson ratio	0.38
Mohs haurdness	4–4.5
Vickers haurdness	549 MPa
Brinell haurdness	392 MPa
CAS Nummer	7440-06-4
History
Diskivery	Antonio de Ulloa (1735)
First isolation	Antonio de Ulloa (1735)
Main isotopes o platinum
Iso­tope Abun­dance Hauf-life (t1/2) Decay mode Pro­duct 190Pt 0.014% 6.5×1011 y α 186Os 192Pt 0.782% >4.7×1016 y α 188Os 193Pt syn 50 y ε 193Ir 194Pt 32.967% stable 195Pt 33.832% stable 196Pt 25.242% stable 198Pt 7.163% >3.2×1014 y α 194Os β−β− 198Hg
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Platinum is a chemical element wi the chemical seembol Pt an an atomic nummer o 78.

Its name is derived frae the Spaingie term platina, which is leeterally translatit intae "little siller".^[2][3] It is a dense, malleable, ductile, precious, gray-white transeetion metal.

Platinum haes sax naiturally occurring isotopes. It is ane o the rarest elements in the Yird's crust an haes an average abundance o approximately 5 μg/kg. It is the least reactive metal. It occurs in some nickel an copper ores alang wi some native deposits, maistly in Sooth Africae, which accoonts for 80% o the warld production.

As a member o the platinum group o elements, as well as o the group 10 o the periodic table o elements, platinum is generally non-reactive. It exhibits a remarkable resistance tae corrosion, even at heich temperaturs, an as sic is considered a noble metal. As a result, platinum is eften foond chemically uncombined as native platinum. Acause it occurs naiturally in the alluvial sands o various rivers, it wis first uised bi pre-Columbie Sooth American natives tae produce artifacts. It wis referenced in European writings as early as 16t century, but it wis nae till Antonio de Ulloa published a report on a new metal o Colombie origin in 1748 that it acame investigated bi scientists.

Platinum is uised in catalytic converters, laboratory equipment, electrical contacts an electrodes, platinum resistance thermometers, dentistry equipment, an jewelry. Acause anly a few hunder tonnes are produced annually, it is a scarce material, an is heichly valuable an is a major precious metal commodity. Bein a hivy metal, it leads tae heal issues upon exposur tae its salts, but due tae its corrosion resistance, it is nae as toxic as some metals.^[4] Compoonds containin platinum, maist notably cisplatin, are applee'd in chemotherapy against certaint types o cancer.^[5]

1. ↑ Meija, Juris; et al. (2016). "Atomic weights of the elements 2013 (IUPAC Technical Report)". Pure and Applied Chemistry. 88 (3): 265–91. doi:10.1515/pac-2015-0305.
2. ↑ "platinum (Pt)." Encyclopædia Britannica Online. Encyclopædia Britannica Inc., 2012. Web. 24 April 2012
3. ↑ Harper, Douglas. "platinum". Online Etymology Dictionary.
4. ↑ "Platinum|" (PDF). Archived frae the original (PDF) on 18 October 2012. Retrieved 28 Juin 2013.
5. ↑ Wheate, NJ; Walker, S; Craig, GE; Oun, R (2010). "The status of platinum anticancer drugs in the clinic and in clinical trials". Dalton transactions (Cambridge, England : 2003). 39 (35): 8113–27. doi:10.1039/C0DT00292E. PMID 20593091.