Question

More number of oxidation states are exhibited by the actinides than by the lanthanides. The main reason for this is:

• A. more energy difference between 5f and 6d orbitals than that between 4f and 5d orbitals
• B. lesser energy difference between 5f and 6d orbitals than that between 4f and 5d orbitals
• C. greater metallic character of the lanthanides than that of the corresponding actinides
• D. more active nature of the actinides

Answer 1

Answer: (B)

lesser energy difference between 5f and 6d orbitals than that between 4f and 5d orbitals

Answer 2

Actinoids display more oxidation states because of very small energy gap between 5f, 6d and 7s sub shells. Thus, the outermost electrons get easily excited to the higher energy level giving variable oxidation state.

Hence, the correct option is (B): lesser energy difference between 5f and 6d orbitals than that between 4f and 5d orbitals