Group 9 element

Group of chemical elements

Group 9, by modern IUPAC numbering, is a group (column) of chemical elements in the d-block of the periodic table. Members of Group 9 include cobalt (Co), rhodium (Rh), iridium (Ir) and meitnerium (Mt). These elements are among the rarest of the transition metals, and as of 2025 rhodium and iridium are the only non-radioactive metals with higher prices per weight than gold.

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