PLATINUM
TRANSITION ELEMENT: NICKEL GROUP
| Atomic number: | 78 |
| Group numbers: | 10 |
| Period: | 6 |
| Electronic configuration: | [Xe] 4f14 5d9 6s1 |
| Formal oxidation number: | +2 +4 |
| Electronegativities: | 2.2 |
| Atomic radius / pm: | 137.3 |
| Relative atomic mass: | 195.084(9) |
Platinum was discovered by Julius Caesar Scaliger (IT) in 1557. The origin of the name comes from the Spanish word platina meaning silver. It is a rare, very heavy, soft, silvery-white metal that resists oxygen, water, corrosion, and acid attacks except aqua regia. Platinum is produced from deposits of native, or elemental. It is used in jewellery, to make crucible and special containers and as a catalyst. Platinum is used with cobalt to produce very strong magnets, also to make standard weights and measures. The price of 99.9 % pure platinum shot is 464.80 € for 5 g.
| Density / g dm-3: | 21450 | (293 K) |
| Molar volume / cm3mol-1: | 9.09 | (293 K) |
| Electrical resistivity / µΩcm: | 10.6 | (20 °C) |
| Thermal conductivity / W m-1K-1: | 71.6 |
| Melting point / °C: | 1768.4 |
| Boiling point / °C: | 3825 |
| Heat of fusion / kJ mol-1: | 19.7 |
| Heat of vaporization / kJ mol-1: | 469 |
| Heat of atomization / kJ mol-1: | 564.42 |
| First ionization energy / kJ mol-1: | 864.39 |
| Second ionization energy / kJ mol-1: | 1791.07 |
| Third ionization energy / kJ mol-1: | - |
| in the atmosphere / ppm: | - |
| in the Earth's crust / ppm: | 0.01 |
| in the oceans / ppm: | - |
| Crystal structure: | face-centered cubic |
| Unit-cell dimensions / pm: | a=392.40 |
| Space group: | Fm3m |
| Isotope | Relative atomic mass | Mass percent (%) |
|---|---|---|
| 190Pt | 189.959930(7) | 0.01(1) |
| 192Pt | 191.961035(4) | 0.79(6) |
| 194Pt | 193.962664(3) | 32.9(6) |
| 195Pt | 194.964774(3) | 33.8(6) |
| 196Pt | 195.964935(3) | 25.3(6) |
| 198Pt | 197.967876(5) | 7.2(2) |
| Balanced half-reaction | Eo / V | |
|---|---|---|
| Pt2+ + 2e- → Pt(s) | +1.2 | |
| PtO2(s) + 2H+ + 2e- → Pt(OH)2(s) | +1.1 | |
| Pt(OH)2(s) + 2e- → Pt(s) + 2OH- | +0.15 | |
| Pt(OH)2(s) + 2H+ + 2e- → Pt(s) + 2H2O | +0.98 | |
| PtCl62- + 2e- → PtCl42- + 2Cl- | +0.68 | |
| PtCl42- + 2e- → Pt(s) + 4Cl- | +0.73 |
| 77 Iridium | ← | 78 Platinum | → | 79 Gold |
Citing this page:
Generalic, Eni. "Platinum." EniG. Periodic Table of the Elements. KTF-Split, 18 Jan. 2024. Web. {Date of access}. <https://www.periodni.com/pt.html>.
