Which out of the two ,`La(OH)_(3) and Lu(OH)_(3)`, is more basic and why?

(a). Of the lanthanides, cerium (Z=58) forms a tetrapositive ion, Ce^(4+) in aqueous solution. Why? (b), The +3 oxidation states of lanthanum (Z=57) , gadolinium (Z=64) and lutetium (Z=71) are especially stable. Why? (c). Why Zr and or Nb anbd Ta exhibit similar properties ? (d). Which oiut of the two La(OH)_3 and Lu(OH)_3 , is more basic and why?

Why Ce(OH)_(3) is more basic than Lu(OH)_(3) ?

Lanthanoids and actinoids are f-block elements in which the last electron enters the anti-penultimate energy level. The most common oxidation state of lanthanoids is +3, though +2 and +4 oxidation states are exhibited by some of the elements. In lanthanoid series, there is a progressive decrease in atomic and ionic radii, known as lanthanoid contraction. Unlike lanthanoids, actinoids show a large number of oxidation states. Which out of La(OH)_3 and Lu(OH)_3 is more basic?

La^(3+) and Lu^(3+) are

Among the lanthanides, La^(3+) and Lu^(3+) ions are

Explain the following : (a) Out of Sc^(3+), Co^(2+) " and "Cr^(3+) "ions, only "Sc^(3+) is colourless in aqueous solutions. (Atomic no.: Co =27, Sc = 21 and Cr =24) (b) The E^(@)Cu^(2+)//Cu for copper metal is positive (+0.34), unlike the remaining members of the first transition series. (c) La(OH)_(3) " is more basic than Lu "(OH)_(3).

Why NaOH cannot be used to separate Al(OH)_(3) and Zn(OH)_(3) ?