GKFix MCQ Question

Why is the third ionization enthalpy of Fe considered lower than that of Mn?

• A. Because the second ionization enthalpy of Fe2+ (d6 to d5) is lower than the second ionization enthalpy of Mn2+ (d5 to d4)
• B. Because the second ionization enthalpy of Mn2+ (d5 to d4) is lower than the second ionization enthalpy of Fe2+ (d6 to d5)
• C. Because Fe has a higher atomic number
• D. Because Mn has a lower atomic radius