Consider the following statements with respect to lanthanides :
1. The basic strength of hydroxides of lanthanides increases from $$La{\left( {OH} \right)_3}$$  to $$Lu{\left( {OH} \right)_3}.$$
2. The lanthanide ions $$L{u^{3 + }},Y{b^{2 + }}$$   and $$C{e^{4 + }}$$  are diamagnetic.
Which of the statement$$(s)$$  given above is/are correct?

Solution :
Basic strength decreases from $$La{\left( {OH} \right)_3}$$  to $$Lu{\left( {OH} \right)_3}.$$
Hence, (1) is incorrect.
$$Ce = \left[ {Xe} \right]4{f^1}5{d^1}6{s^2};C{e^{4 + }}$$       $$ = \left[ {Xe} \right]$$
$$Yb = \left[ {Xe} \right]4{f^{14}}6{s^2};Y{b^{2 + }}$$      $$ = \left[ {Xe} \right]4{f^{14}}$$
$$Lu = \left[ {Xe} \right]4{f^{14}}5{d^1}6{s^2};L{u^{3 + }}$$      $$ = \left[ {Xe} \right]4{f^{14}}$$