d and f BLOCK ELEMENTS

What is the primary factor that makes the +3 oxidation state the most stable for Lanthanoids?

• The resulting Ln³⁺ ion achieves a stable 4fⁿ electronic configuration
• The low ionization energy for the third electron
• The high electronegativity of Lanthanoids
• The large atomic size of Lanthanoids

Which of the following best describes the trend in the ionic radii of Lanthanoid M³⁺ ions as shown in Figure 4.6?

• A steady decrease from La³⁺ to Lu³⁺
• An increase from La³⁺ to Lu³⁺
• A zig-zag pattern with no overall trend
• A constant radius throughout the series

What is the electronic configuration of the most common stable ion formed by Lutetium?

• 4f¹⁴
• 4f¹³
• 4f¹²
• 5d¹

Which Lanthanoid element is the first in the series and forms the Ln³⁺ ion with what electronic configuration?

• Lanthanum; 4f⁰
• Cerium; 4f¹
• Lutetium; 4f¹⁴
• Promethium; 4f⁵

What is the electronic configuration of the most common stable ion formed by Gadolinium?

• 4f⁷
• 4f⁶
• 4f⁸
• 5d¹