The metal(s) which does/ do not form amalgam is/are:

To form amalgam, the metal ion is first reduced to a metal atom, which is then solvated by a mercury atom. As a result, Mercury must solvate iron atoms by incorporating into the iron lattice, which is extremely difficult due to the iron's high stability. This iron's stability is due to its electronic configuration, which prevents the transition metal Hg from forming amalgam with iron.