Question

The common oxidation state shown by Europium in their compounds is

• A. $+1$
• B. $+3$
• C. $+5$
• D. $+6$

Answer 1

Answer: (B)

[ $Xe]4f^{n}6s^2$ 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. Europium being a member of lanthanoid series, also shows $+3$ oxidation state.