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प्रश्न
Actinoid contraction is greater from element to element than the lanthanoid contraction, why?
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उत्तर
- Actinoid contraction is greater from element to element than lanthanoid contraction. The 5f orbitals in Actinoids have a very poorer shielding effect than 4f orbitals in lanthanoids.
- Thus, the effective nuclear charge experienced by electrons in valence shells in the case of actinoids is much more than that experienced by lanthanoids.
- In actinoids, electrons are shielded by 5d, 4f, 4d and 3d whereas in lanthanoids, electrons are shielded by 4d, 4f only.
- Hence, the size contraction in actinoids is greater as compared to that in lanthanoids.
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