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

The reactivity of lanthanons are less than aluminium due to high I.P which arises due to lanthanoid contraction.
(1) Eu (II) has stable electronic confi-guration, i.e., [Xe] 4f⁷ 5d^o 6s^o.
(2) As the size of the lanthanoid ions decreases, the covalent character of the hydroxides increases. Hence, basic strength decreases.
(4) Ce⁺⁴ is a good oxidizing agent and easily converted into Ce⁺³.