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

The reason for greater range of oxidation states in actinoids is attributed to
  1. the radioactive nature of actinoids.
  2. actinoid contraction.
  3. 5f, 6d and 7s levels having comparable energies.
  4. 4f and 5d levels being close in energies.

Solution

The minimum energy gap between 5f, 6d  & 7s subshell. That's why e− excitation will be easier.

Asked in: NEET 2017

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