d and f BLOCK ELEMENTS

What is the primary electronic factor that differentiates the stability of Eu²⁺ from Eu³⁺?

• Eu²⁺ achieves a half-filled (4f⁷) configuration, while Eu³⁺ has a 4f⁶ configuration
• Eu²⁺ has a filled f-subshell, while Eu³⁺ has a half-filled f-subshell
• Eu²⁺ has no unpaired electrons, while Eu³⁺ has seven
• Eu²⁺ is diamagnetic, while Eu³⁺ is paramagnetic

What is the primary electronic factor that differentiates the stability of Ce⁴⁺ from Ce³⁺?

• Ce⁴⁺ achieves a noble gas (4f⁰) configuration, while Ce³⁺ has a 4f¹ configuration
• Ce⁴⁺ has a half-filled f-subshell, while Ce³⁺ has a partially filled f-subshell
• Ce⁴⁺ has no unpaired electrons, while Ce³⁺ has one
• Ce⁴⁺ is paramagnetic, while Ce³⁺ is diamagnetic

Which Lanthanoid tripositive ion (Ln³⁺) has an electronic configuration of 4f¹⁰?

• Holmium
• Dysprosium
• Erbium
• Thulium

Which Lanthanoid tripositive ion (Ln³⁺) has an electronic configuration of 4f⁵?

• Promethium
• Samarium
• Europium
• Gadolinium

Which of the following best summarizes the electronic configuration of the most stable ion formed by Lutetium (Lu)?

• 4f¹⁴
• 4f¹³
• 4f¹²
• 5d¹