The electronic configuration of Eu (Atomic No. 63), Gd (Atomic No. 64) and Tb (Atomic No. 65) are:

Options

A. `"["Xe"]"4f^(6)5d^(1) 6s^(1), "["Xe"]"4f^(7)5d^(1) 6s^(2) and "["Xe"]"4f^(8)5d^(1)6s^(2)`
B. `"["Xe"]"4f^(7)5d^(1) 6s^(2), "["Xe"]"4f^(7)5d^(1) 6s^(2) and "["Xe"]"4f^(9)6s^(2)`
C. `"["Xe"]"4f^(7)5d^(1) 6s^(2), "["Xe"]"4f^(8) 6s^(2) and "["Xe"]"4f^(8)5d^(1)6s^(2)`
D. `"["Xe"]"4f^(6)5d^(1) 6s^(2), "["Xe"]"4f^(7)5d^(1) 6s^(2) and "["Xe"]"4f^(9)6s^(2)`

Answer

B

Explanation

B It is the correct answer