why are elements 57 through 70 and 89 through 102 found separately at the bottom of the periodic table?

Question

periodic table

Answer 1

The first series, 57-70, is called the rare earths. They are also called the lanthanides, because they follow and resemble lanthanum on the periodic table. They differ from one another only in the number of electrons they have in the 4f level.

The second series is similar. These elements differ in the number of electrons they have in their 5f orbitals. They are all radioactive. Only Ac (actinium), Th, Pa, and U occur in nature. They are called the actinides.

Answer 2

57-70 and 89-102 by atomic number go in the transition metals, but they are not transition metals and in turn are put into there own catigory at the bottom of the table (I may be wrong though)