Why are lanthanides and Actinides are placed sepatately at the bottom of the peridic table ?

Lanthanides and actinides resemble in

Why are lanthanides and actinides place at the bottom of the periodic table?

What is meant by lanthanides and actinides?

The Lanthanides and Actinides are placed in group and period number :

Lanthanides and Actinides generally differ in

Isotopes of an element are placed at the same place in the long form of the periodic table.

Group of elements which are kept at the bottom of periodic table.

All lanthanides are supposed to be present in group 3 of the periodic table.

In the long or modern form of the periodic table, the element in the periodic table have been divided into four blocks, s-p-d -and f -. Each period begins with the filling of new energy shell. Two series of f -block elements are placed at the bottom of the periodic table. The element with Z=39 belongs to

In the long or modern form of the periodic table, the element in the periodic table have been divided into four blocks, s-p-d -and f -. Each period begins with the filling of new energy shell. Two series of f -block elements are placed at the bottom of the periodic table. Which of the following ions is most stable?