Why do actinides exhibit multiple oxidation states?

Actinides exhibit multiple oxidation states mainly because their 5f, 6d, and 7s electrons are close in energy and can all participate in bonding.

Explanation in simple terms:

1. The energy difference between these orbitals is small, so electrons can be lost from different shells.
2. This allows actinides to form various ions with different charges.
3. As a result, actinides show oxidation states ranging from +3 to +6 (sometimes +7) depending on the element and chemical environment.

Example:

• Uranium can exist as U³⁺, U⁴⁺, U⁵⁺, and U⁶⁺.
• Thorium mainly shows Th⁴⁺, but other actinides have multiple states.

In short: Multiple oxidation states happen because f, d, and s electrons are all available for bonding.