Gadolinium belongs to 4f series. Its atomic number is 64. Which of the following is the correct electronic configuration of gadolinium?

Gadolinium belongs to 4f series. It is a lanthanide. Its atomic number is 64. The correct electronic configuration of gadolinium is: [Xe]4f75d16s2. The atomic number of Xe is 54. Thus we have to account for an additional 64 - 54 = 10 electrons. Lanthanoids have a general electronic configuration of [Xe]4fn6s2