Answer
Please see the work below.
Work Step by Step
Transition elements are the elements of group 3 to 12 having outer electronic configuration $(n-1) d^{1-10} ns^{1-2}$. There are four transition series which are 3d, 4d, 5d, and 6d.
An example of a transition element is Iron.
Lanthanides are characterized by the filling of 4 f-orbitals. They consist of the elements of the following lanthanum from Ce to Lu.
An example of lanthanide is Uranium.
Actinides are characterized by the filling of 5f-orbitals. They consist of the elements following actinium from Th to Lr.
An example of an Actinide is Thorium.
