Rearrangements wonât occur if the initially formed carbocation is the most thermodynamically stable out of all the possible isomers. For example, if you use t-butyl bromide in a Friedel-Crafts alkylation, it will not rearrange, since the t-butyl c... This page may be out of date. Save your draft before refreshing this page.
Platinum was first used for minting coins in Spanish-colonized America. Following the discovery of platinum in gold rocks, the Spaniards were unable to use it for a long time because they had no technology for processing this metal.latinum was first used for minting coins in Spanish-colonized America. Following the discovery of platinum in gold rocks, the Spaniards were unable to use it for a long time because they had no technology for processing this metal.
Platinum is found as the free element, usually mixed with other metals including gold, nickel, copper, palladium, ruthenium, rhodium, iridium, and osmium in Columbia, the USA, Ontario (Canada) and the Urals (USSR). Platiniridium is a naturally occurring platinum/iridium alloy.