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 This page may be out of date.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.
Prepared from urine, it was the first element to be chemically discovered. 27: Cobalt: 1735: G. Brandt: 1735: G. Brandt: Proved that the blue color of glass is due to a new kind of metal and not bismuth as thought previously. 78: Platinum: 1748: A. de Ulloa: First description of a metal found in South American gold was in 1557 by Julius Caesar Scaliger.