Which of the following statement is not correct ?

Options

A. `La(OH)_(3)` is less basic than `Lu(OH)_(3)`.
B. IN lanthanide series, ionic radius decreases from `La^(3+) to Lu^(3+)` ion.
C. La is actually an elements of transition series rather than lanthanides.
D. Atomic radius of Zr and Hf are same because of lanthanoid contraction.

Answer

A

Explanation

`La(OH)_(3)` is more basic than `lu(OH)_(3)` because as the size of lanthanide ions decreases from `La^(3+)` to `Lu^(3+)`, the covalent character increases and hence basis strength of their hydroxides decreases.