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Group 9 element
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<table><tbody><tr><th colspan="2">↓ <a href="/facts/Period_(periodic_table)/WpGUFh5V">Period</a></th></tr><tr><th><a href="/facts/Period_4_element/BgDFfE26">4</a></th><td><a href="/facts/Cobalt/gqhScEw4">Cobalt</a> (Co)27 <a href="/facts/Transition_metal/0slGWoLQ">Transition metal</a></td></tr><tr><th><a href="/facts/Period_5_element/xLJUWWDS">5</a></th><td><a href="/facts/Rhodium/xmBd9aFG">Rhodium</a> (Rh)45 <a href="/facts/Transition_metal/0slGWoLQ">Transition metal</a></td></tr><tr><th><a href="/facts/Period_6_element/9YleCXwf">6</a></th><td><a href="/facts/Iridium/TFQutoj1">Iridium</a> (Ir)77 <a href="/facts/Transition_metal/0slGWoLQ">Transition metal</a></td></tr><tr><th><a href="/facts/Period_7_element/H5QuVHGQ">7</a></th><td><a href="/facts/Meitnerium/pKaD3sRY">Meitnerium</a> (Mt)109 unknown chemical properties</td></tr><tr><td colspan="2"><p><i>Legend</i></p><table><tbody><tr><td><a href="/facts/Primordial_element/lFAUqHDv">primordial element</a></td></tr><tr><td><a href="/facts/Synthetic_element/azU9Nr1m">synthetic element</a></td></tr></tbody></table></td></tr></tbody></table> <p>Group 9, by modern <a href="/facts/Group_(periodic_table)/YGBcUabv">IUPAC</a> numbering, is a group (column) of <a href="/facts/Chemical_element/0jducgWD">chemical elements</a> in the <a href="/facts/D-block/BbzD5jUU">d-block</a> of the <a href="/facts/Periodic_table/umdGIfUb">periodic table</a>. Members of Group 9 include <a href="/facts/Cobalt/gqhScEw4">cobalt</a> (Co), <a href="/facts/Rhodium/xmBd9aFG">rhodium</a> (Rh), <a href="/facts/Iridium/TFQutoj1">iridium</a> (Ir) and <a href="/facts/Meitnerium/pKaD3sRY">meitnerium</a> (Mt). These elements are among the rarest of the <a href="/facts/Transition_metal/0slGWoLQ">transition metals</a>, and as of 2025 rhodium and iridium are the only non-radioactive metals with higher prices per weight than gold. </p><p>Like other groups, the members of this family show patterns in <a href="/facts/Electron_configuration/TQjRr22P">electron configuration</a>, especially in the outermost shells, resulting in trends in chemical behavior; however, rhodium deviates from the pattern. </p>