Part b an element belongs to group 9. what common name might be used to describe the group to which this element belongs?

Group 9 of the periodic table is comprised of cobalt (Co), Rhodium (Rh), Iridium (Ir), and one which is still chemically uncharacterized Meitnerium (Mt). These elements are all metals. These metals are termed Transition metals.

These metals are in the d-block because the last elements are in the d-orbitals.