GKFix MCQ Question

What is the primary electronic factor that differentiates the stability of Tb⁴⁺ from Tb³⁺?

• A. Tb⁴⁺ achieves a half-filled (4f⁷) configuration, while Tb³⁺ has a 4f⁸ configuration
• B. Tb⁴⁺ has a filled f-subshell, while Tb³⁺ has a half-filled f-subshell
• C. Tb⁴⁺ has one unpaired electron, while Tb³⁺ has two
• D. Tb⁴⁺ is diamagnetic, while Tb³⁺ is paramagnetic