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 This page may be out of date.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.
In Canada in 1888, platinum was discovered in the nickel-copper ores of Ontario. Between the end of the First World War and the 1950s, Canada was the world's major source of supply. In 1924 a farmer in the Transvaal province of South Africa discovered several nuggets of platinum in a riverbed.etween the end of the First World War and the 1950s, Canada was the world's major source of supply. In 1924 a farmer in the Transvaal province of South Africa discovered several nuggets of platinum in a riverbed.