Question

can anyone tell me why d block elements are called transition elements and f block elements called inner transition elements????

Answer 1

The d-block elements are also called transition elements because of forming a bridge between the chemically active elements of s-block and less active elements of 13th and 14th group of p-block.
Since the last electron added to each element of this group is filled in f-orbital, these two series (the lanthanoids and the actinoids) of elements are hence called the inner transition elements.