d and f BLOCK ELEMENTS

What is the electronic configuration of Praseodymium (Pr) for its Ln³⁺ ion?

• 4f¹
• 4f²
• 4f³
• 4f⁴

What is the electronic configuration of Cerium (Ce) for its outermost electrons?

• 5d¹6s²
• 4f¹5d¹6s²
• 4f¹6s²
• 4f²6s²

What is the electronic configuration of Lanthanum (La) for its outermost electrons?

• 5d¹6s²
• 4f¹5d¹6s²
• 4f¹6s²
• [Xe] 5d¹6s²

Which of the following best describes the electronic reason for the stability of the common +3 oxidation state in Lanthanoids?

• The Ln³⁺ ions achieve configurations close to the general 4fⁿ pattern, which is relatively stable
• The +3 state results in completely filled orbitals
• The +3 state results in completely empty orbitals
• The +3 state minimizes the total number of electrons

What is the primary difference in the electronic configurations of Sm²⁺ and Sm³⁺ ions?

• Sm²⁺ has a 4f⁵ configuration (half-filled), while Sm³⁺ has a 4f⁴ configuration
• Sm²⁺ has a 4f⁴ configuration, while Sm³⁺ has a 4f⁵ configuration
• Sm²⁺ has a 4f⁶ configuration, while Sm³⁺ has a 4f⁵ configuration
• Sm²⁺ has a 4f⁵ configuration, while Sm³⁺ has a 5d¹ configuration