Question

Which of the following oxidation state is common for all lanthanoids?

• A. 2
• B. 3
• C. 4
• D. 5

Answer 1

Answer: (B)

3

$\left[Xe\right]{4f}^n{6s}^2$ is the general configuration of Lanthanoids,it may seem $+2$ should be the common oxidation state but relative stability depends on other factors as well,Landthanoids most commonly shows $+3$ oxidation state due to high hydration enthalpy than of $+2$ oxidation state.