NEETChemistryD and F Block ElementsMCQ+4 / −1
Reason of lanthanoid contraction is
- Anegligible screening effect of 'f'- orbitals
- Bincreasing nuclear charge
- Cdecreasing nuclear charge
- Ddecreasing screening effect.
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Correct answer: A
The shape of f-orbitals is very much diffused and they have poor shielding effect. The effective nuclear charge increases which causes the contraction in the size of electron charge cloud. This contraction in size is quite regular and known as lanthanoid contraction.
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