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Oxidation & Electrons | Appearance & Characteristics Reactions | Compounds | Radius | Conductivity Abundance & Isotopes 
Platinum eagle coins. |
General:
| Name: Platinum | Symbol: Pt |
| Type: Transition Metal | Atomic weight: 195.09 |
| Density @ 293 K: 21.45 g/cm3 | Atomic volume: 9.10 cm3/mol |
| Discovered: Platinum was discovered by South American peoples who produced artifacts of a white gold-platinum alloy. The first written account of platinum was from Julius C Scaliger in 1557. Its name comes from the Spanish word 'platina', meaning little silver. | |
States
| State (s, l, g): solid | |
| Melting point: 2041 K (1768 oC) | Boiling point: 4093 K (3820 oC) |
Energies
| Specific heat capacity: 0.13 J g-1 K-1 | Heat of atomization: 564 kJ mol-1 |
| Heat of fusion: 22.17 kJ mol-1 | Heat of vaporization: 510.45 kJ mol-1 |
| 1st ionization energy: 870 kJ mol-1 | 2nd ionization energy: 1791 kJ mol-1 |
| 3rd ionization energy: kJ mol-1 | Electron affinity: 205.3 kJ mol-1 |
Oxidation & Electrons
| Shells: 2, 8, 18, 32, 17, 1 | Electron configuration: [Xe] 4f14 5d9 6s1 |
| Minimum oxidation number: 0 | Maximum oxidation number: 6 |
| Min. common oxidation no.: 0 | Max. common oxidation no.: 4 |
| Electronegativity (Pauling Scale): 2.28 | Polarizability volume: 6.5 Å3 |
Appearance & Characteristics
| Structure: fcc: face-centered cubic | Color: silvery-white |
| Hardness: 3.5 mohs | |
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Harmful effects:
Platinum is considered to be non-toxic. Characteristics: Platinum is a precious metal; soft, silvery-white, and dense with a beautiful lustrous sheen. It is malleable and ductile and has a high melting point. Platinum does not oxidize in air even at high temperatures and is unaffected by common acids. It dissolves in aqua regia (mixture of nitric acid and hydrochloric acid in the ratio 1:3) forming chloroplatinic acid (H2PtCl6). It is also corroded by halogens, cyanides, sulfur, and caustic alkalis. Uses: Platinum is widely used as a catalyst for chemical reactions. The most important use of platinum is in vehicles, as a catalytic converter, facilitating the complete combustion of unburned hydrocarbon passing through the exhaust. Platinum is used in jewelry, decoration and dental work. The metal and its alloys are also used for electrical contacts, fine resistance wires and medical / laboratory instruments. An alloy of platinum and cobalt is used to produce strong permanent magnets. The metal is also used to make electrodes sealed in glass (as its thermal coefficient of expansion is almost equal to that of glass). |
Reactions
| Reaction with air: none | Reaction with 6 M HCl: none |
| Reaction with 3 M HNO3: none | Reaction with 6 M NaOH: none |
Compounds
| Oxide(s): Pt2O2 | Chloride(s): PtCl2, PtCl4 |
| Hydride(s): none |
Radius
| Atomic radius: 135 pm | Ionic radius (1+ ion): pm |
| Ionic radius (2+ ion): 94 pm | Ionic radius (3+ ion): pm |
| Ionic radius (2- ion): pm | Ionic radius (1- ion): pm |
Conductivity
| Thermal conductivity: 71.6 W m-1 K-1 | Electrical conductivity: 9.4 x 106 S m-1 |
Abundance & Isotopes
| Abundance earth's crust: 5 parts per billion by weight, 0.5 parts per billion by moles | |
| Abundance solar system: 9 part per billion by weight, 0.06 parts per billion by moles | |
| Cost, pure: $4700 per 100g | |
| Cost, bulk: $1200 per 100g | |
| Source: Platinum is an extremely rare metal and can be found uncombined in alluvial deposits often accompanied by small amounts of other platinum family metals. A major source of platinum is the ore sperrylite (PtAs2). It is also found in the mineral cooperite (PtS). Platinum is also produced commercially as a by-product of nickel refining from copper-nickel ores. | |
| Isotopes: Platinum has 35 isotopes whose half-lives are known, with mass numbers 202 to 168. Of these five are stable, 192Pt, 194Pt, 195Pt, 196Pt and 198Pt. | |
