Q. The lanthanide ion having four unpaired electrons is (Given : Atomic numbers of Ce = 58, Nd = 60, Tb = 65 and Ho = 67)
A) Ho³⁺
B) Nd³⁺
C) Ce³⁺
D) Tb³⁺
Explanation
[Solution from source] Ln³⁺ ions have 4fⁿ configurations with n = Z − 57: Ce³⁺ 4f¹ has one unpaired electron, Nd³⁺ 4f³ three, Tb³⁺ 4f⁸ six, and Ho³⁺ 4f¹⁰ has four. Answer (1).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.