GKFix MCQ Question

Why is the +2 oxidation state particularly stable for Europium (Eu) and Ytterbium (Yb)?

• A. Because they have fewer protons.
• B. Because they are lighter elements.
• C. Because Eu2+ has a half-filled f-subshell (4f7) and Yb2+ has a fully-filled f-subshell (4f14).
• D. Because they are radioactive.