(1) The lanthanide series fill up the 5f sublevel and the actinide series fill up the 4f sublevel.
(2) There are four lanthanide metals that have properties similar to the d block. These are cerium, Ce, lutetium, Lu, and gadolinium, Gd and praseodymium, Pr
(3) The first, middle, and last member of the lanthanide series have properties of the f block and the d block.
(4) General electronic configuration of f – block elements is
(n–2)f1–14(n–1)d0–1ns2
Only(1)(2)and(3)(1)and(2)(1),(2)and(4)