d- and f-Block Elements · JEE Main previous year questions

2006 1 question

1. Q1272006 · 29 Apr 2006 · Shift 1

   Lanthanoid contraction is caused due to :

   1. A.the appreciable shielding on outer electrons by 4f electrons from the nuclear charge
   2. B.the appreciable shielding on outer electrons by 5d electrons from the nuclear charge
   3. C.the same effective nuclear charge from Ce to Lu
   4. D.the imperfect shielding on outer electrons by 4f electrons from the nuclear charge
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   Answer: D