Question

lanthanides and actinides are kept separately in the modern periodic table why?

Answer 1

Here is Ur answer,

According to Mendeleev, in the modern periodic table, there is no place for isotopes and lanthanides and actinides.
So they are kept at the bottom of periodic table.

Hope it helps u......

Answer 2

It is because of their electronic configuration and they are also known as inner transition metals.
they also belong to the same group.