Question

Arrange $C{e}^{3+}$, $L{a}^{3+}$, $P{m}^{3+}$, and $Y{b}^{3+}$ in increasing order of their ionic radius:

• A. $Y{b}^{3+}<P{m}^{3+}<C{e}^{3+}<L{a}^{3+}$
• B. $C{e}^{3+}>Y{b}^{3+}<P{m}^{3+}<L{a}^{3+}$
• C. $Y{b}^{3+}>P{m}^{3+}<L{a}^{3+}<C{e}^{3+}$
• D. none of these

Answer 1

The correct option is A $Y{b}^{3+}<P{m}^{3+}<C{e}^{3+}<L{a}^{3+}$

Atomic and ionic radii of Lanthanides decrease from $La$ to $Lu$.

Their order of ionic radii: $Y{b}^{+3}<P{m}^{3+}<C{e}^{3+}<L{a}^{+3}$