D-block

The d-block of the periodic table of the elements consists of those periodic table groups that contain elements in which, in the atomic ground state, the highest-energy electron is in a d-orbital. The d-block elements are often also known as transition metals.

Although Lutetium and Lawrencium are in the d-block, they are not considered transition metals but lanthanide and actinide according to IUPAC. Group 12 elements are also in the d-block but are considered post-transition metals if their d-subshell is completely filled.