Question

The correct order of ionic radii of $Y^{3+} L a^{3+} E u^{3+} $ and $L u^{3+}$ is
(Atomic nos. $Y =39, La =57, Eu =63, Lu =71$ )

• A. $Y^{3+} < L a^{3 +} < E u^{3+} < L u^{3+}$
• B. $Y^{3+} < L u^{3+} < E u^{3+} < L a^{3+}$
• C. $L u^{3+} < E u^{3 +} < L a^{3+} < Y^{3+}$
• D. $L a^{3+} < E u^{3+} < L u^{3+} < Y^{3+}$

Answer 1

Answer: (B)

Ongoing from $La^{+3}$ to $ Lu^{+3}$ ion size shrinks due to Lanthanide contraction.