(1) The decrease in ionic radii of the lanthanides from 103 pm (La3+) to 86 pm (Lu3+) in the lanthanide series.
(2) The Basic nature increases from Ce(OH)3 to Lu(OH)3
(3) The covalent nature in M(OH)3 will decrease from Ce(OH)3 to Lu(OH)3
(4) The E∘ value increases slightly due to Lanthanide contraction
Both(2)and(3)Only(2)Both(1)and(2)(1),(2)and(4)