Question

Actinides exhibit a larger number of oxidation state than that of corresponding lanthanides. The reason behind this aspect is :

• A. lesser energy difference between 5f and 6d-orbitals than between 4f and 5d-orbitals
• B. larger atomic size of actinides than the lanthanides
• C. more energy difference between 5f and 6d orbitals than between 4f and 5d-orbitals
• D. greater reactive nature of the actinides than the lanthanides

Answer 1

The correct option is A lesser energy difference between 5f and 6d-orbitals than between 4f and 5d-orbitals

Because of lesser energy difference between $5f$ and $6d$ orbitals than that between $4f$ and $5d$-orbitals actinides exhibit larger number of oxidation state than that of corresponding lanthanides. There is no large energy difference for pulling out the electrons in case of actinides.