In Mendeleev's 1871 periodic desk, copper, silver, and gold are shown 2 times, once less than group VIII (with the iron triad and platinum group metals), and once underneath group IB. Group IB was Even so parenthesised to note that it had been tentative. Mendeleev's most important criterion for group https://dominicktiync.educationalimpactblog.com/57357007/details-fiction-and-situs-bigbos777