JEE Main 2005Annual, Paper 1ChemistryEasyd- and f-Block Elements158× since 2002Which of the following factors may be regarded as the main cause of lanthanide contraction?AOption A. Poor shielding of one of 4f electron by another in the subshellBOption B. Effective shielding of one of 4f electrons by another in the subshellCOption C. Poorer shielding of 5d electrons by 4f electronsDOption D. Greater shielding of 5d electrons by 4f electronsCheckSkip · show solution
