Which one of the following statements related to lanthanons is incorrect ?

Options

A. Europium shows `+2` oxidation state.
B. The basically decreases as the ionic radius decreases from Pr to Lu
C. All the lanthanons are much more reactive than aluminium
D. Ce `(+4)` solution are widely used as oxidising agent in volumetric analysis

Answer

C

Explanation

Eu(63) = `4t^(2)-5d^(0), 6s^(2), Eu^(2+)=4f^(7)`
In lanthanoids series, ionic radius decrease and covalent character increases, thus basicity decrease. Lanthanons are less reactive than aluminium due to high ionisation potential. The reason for this high ionisation potential is lanthanoiid contraction.`Ce^(4+)` is a good oxidising agent, it is easily converted to `Ce^(3+)`