BIGBOS777 LINK SLOT NO FURTHER A MYSTERY

In Mendeleev's 1871 periodic table, copper, silver, and gold are mentioned 2 times, when underneath group VIII (with the iron triad and platinum group metals), and once below group IB. Group IB was Nevertheless parenthesised to note that it was tentative. Mendeleev's key criterion for team assignment was the most oxidation point out of an element: