Q. Gadolinium belongs to 4f series. It's atomic number is 64. Which of the following is the correct electronic configuration of gadolinium ?
A) [Xe] $4f^75d^16s^2$
B) [Xe] $4f^65d^26s^2$
C) [Xe] $4f^86d^2$
D) [Xe] $4f^95s^1$
Explanation
[Solution] $_{64}Gd$ = [Xe] $4f^75d^16s^2$ (half-filled 4f is extra stable). Answer (1).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.