ChemistryEasy158×since 2002Q801Which of the following factors may be regarded as the main cause of lanthanide contraction?APoor shielding of one of 4f electron by another in the subshellBEffective shielding of one of 4f electrons by another in the subshellCPoorer shielding of 5d electrons by 4f electronsDGreater shielding of 5d electrons by 4f electronsCheck answerSkip