I. The basic character of hydroxides decreases from La(OH)3 to Lu(OH)3. Thus La(OH)3 is the most basic among lanthanoid hydroxides. II. Zr4+ and Hf4+ is almost similar in size due to lanthanide contraction. III. Cerium exhibits +4 oxidation state in aqueous solution and possesses the tendency to attain +3 oxidation state. Therefore Ce4+ is a good oxidising agent.