General description: The Platinum has been used for thousands of years but it was not recognized as an element until 1735. Among the three precious metals, gold, silver and Platinum, is the rarest and most valuable. The Platinum, chemically inert and resistant to corrosion, does not rust when exposed to the atmosphere as opposed to the silver. Is silvery grey, grey-white or white; It is opaque, and has metallic luster. It is slightly denser than pure gold and is almost two times more dense than silver. Antique Jewelers had difficulty in achieving the 1,773? C (DO 3,223? (F) necessary for melting Platinum. It was not until 1920 that the technology advanced enough to work this precious metal Platinum applications are numerous and varied, for example used to make standards of weights and measures, used in the electronics industry for electrical contacts subjected to elevated temperatures and in the manufacture of electrodes subjected to chemical attacks.
A current and important use is in the manufacture of catalysts for tubes exhaust where covers a ceramic honeycomb with Platinum. Platinum is formed in igneous rocks, usually as ores in which the grains are too tiny to be able to be observed with the naked eye. Also occurs in deposits type pleasure in sands and gravels of rivers and glacial deposits, usually as grains and more rarely as nuggets. The main deposits of Platinum have been in South Africa, Canada (Sudbury), USA (Alaska), Russia (Perm River and other rivers from the Urals), Australia, Colombia and Peru. Distribution of natural isotopes N of mass atomic properties. 190% 0.01 192 0.79 194 32.90 195 33.80 196 25.30 198 7.20 Structure crystalline cubic face centered structure electronic Xe 4f 14 5 d 9 6s 1 work Photo-electric (eV) 5.3 function atomic number 78 weight Atomic (amu) 195,08 potential of ionization N. 1 eV 9.0 2 18.6 Radio Atomic Goldschmidt (nm) 0,138 section trans.