d and f BLOCK ELEMENTS

What electronic configurations contribute to the stability that results in abnormally low third ionization enthalpies for La, Gd, and Lu?

• s² and p⁶ configurations
• Empty, half-filled, and full f subshells
• d⁵ and d¹⁰ configurations
• s¹ and p³ configurations

What is the typical range of second ionization enthalpies for lanthanoids?

• Approximately 600 kJ mol⁻¹
• Approximately 900 kJ mol⁻¹
• Approximately 1200 kJ mol⁻¹
• Approximately 1500 kJ mol⁻¹

What is the typical range of first ionization enthalpies for lanthanoids?

• Approximately 400 kJ mol⁻¹
• Approximately 600 kJ mol⁻¹
• Approximately 800 kJ mol⁻¹
• Approximately 1000 kJ mol⁻¹

Why are La³⁺ and Lu³⁺ ions colorless?

• They lack d electrons
• They are too large
• They have empty or full f subshells
• They only absorb UV light

What is the primary reason for the color observed in many trivalent lanthanoid ions?

• d-d electron transitions
• f-f electron transitions
• Charge transfer transitions
• s-p electron transitions