1)

Knowing that the chemistry of lanthanoids(Ln) is dominated by its +3 oxidation state, which of the following statements is incorrect?


A) The ionic size of Ln (III) decrease in general with increasing atomic number

B) Ln (III) compounds are generally colorless.

C) Ln (III) hydroxide are mainly basic in character

D) Because of the large size of the Ln (III) ions the bonding in its compounds is predominantly ionic in character.

Answer:

Option B

Explanation:

Most of the Ln3+  compounds except La3+ and Lu3+ are coloured due to the presence of f-electrons.