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 This page may be out of date.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.
NicÃ©phore NiÃ©pce and Daguerre. The first photographic process â heliography â was invented around 1824 by NicÃ©phore NiÃ©pce. Images were obtained with bitumen of Judea spread on a silver plate after an exposure time of several days. In 1829, NiÃ©pce associated Louis Jacques MandÃ© Daguerre to his research.