The actinoids exhibits more number of oxidation states in general than the lanthanoids. This is because
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the 5f orbitals are more buried than the 4f orbitals
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there is a similarity between 4f and 5f orbitals in their angular part of the wave function
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the actinoids are more reactive than the lanthanoids
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the 5f orbitals extend further from the nucleus than the 4f orbitals
