Total number of elements present in third group of modern periodic table

Group 3is agroupofelementsin theperiodic table. This group, like otherd-blockgroups, should contain four elements, but it is not agreed what elements belong in the group.Scandium (Sc)andyttrium (Y)are always included, but the other two spaces are usually occupied bylanthanum (La)andactinium (Ac), or bylutetium (Lu)andlawrencium (Lr); less frequently, it is considered the group should be expanded to 32 elements (with all thelanthanidesandactinidesincluded) or contracted to contain only scandium and yttrium