Question

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

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

Answer 1

Answer: (D)

$Y^{3+}<L{u}^{3+}<E{u}^{3+}<L{a}^{3+}$

Due to lanthanide contraction size of lanthanides ions decreases from $L{a}^{3+}$ to $L{u}^{3+}$.

so order is $Y^{3+}<L{u}^{3+}<E{u}^{3+}<L{a}^{3+}$

Hence, the correct option is $D$.