Question

In context of the lanthanoids, which of the following statements is not correct?

• A. There is a gradual decrease in the radii of the members with increasing atomic number
• B. All the members exhibit a stable +3 oxidation state
• C. Because of their similar properties, the separation of lanthanoids is not easy
• D. All $L{n}^{3+}$ show colour in aqueous solution

Answer 1

The correct option is D All $L{n}^{3+}$ show colour in aqueous solution

Some of lanthanoid elements do not show colour in aqueous in $+3$ oxidation state. Ex- $L{a}^{3+},C{e}^{3+},G{d}^{3+},T{b}^{3+},Y{b}^{3+}$ and $L{u}^{3+}$