Question

The reason for greater range of oxidation states in actinoids is attributed to:

• A. The radioactive nature of actinoids
• B. Actinoid contraction
• C. $5f,6dand7s$ levels having comparable energies
• D. $4fand5d$ levels being close in energies

Answer 1

The correct option is C $5f,6dand7s$ levels having comparable energies

Minimum or comparable energy gap between $5f,6d$ and$7s$ subshell makes electron excitation easier. Hence, there is a greater range of oxidation states in actinoids.