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

Options

A. `[Xe]4f^(2)5d^(1)6s^(2)`
B. `[Xe]4f^(6)5d^(2)6s^(2)`
C. `[Xe]4f^(8)6d^(2)`
D. `[Xe]4f^(9)5s^(1)`

Answer

A

Explanation

`._(64)Gd hArr underset(54)([Xe])4f^(7)5d^(1)6s^(2)`
Half filled 'f' subshell is more stable