D-And F-Block Elements Ques 515
Question: Arrange (I) $ C{{e}^{3+}} $ , (II) $ L{{a}^{3+}} $ , (III) $ P{{m}^{3+}} $ , and (IV) $ Y{{b}^{3+}} $ in increasing order of their ionic radii.
Options:
A) IV<III<I<II
B) I<IV<III<II
C) IV<III<II<I
D) III<II<I<IV
Show Answer
Answer:
Correct Answer: A
Solution:
Ionic radii decrease across lanthanide series due to lanthanide contraction. As all ions are in +3 O.S., ionic radii will follow the trend of atomic radii.
$ \therefore \underset{( Z=57 )}{\mathop{L{{a}^{3+}}}},>\underset{(Z=58)}{\mathop{C{{e}^{3+}}}},>\underset{(Z=61)}{\mathop{P{{m}^{3+}}}},>\underset{(Z=70)}{\mathop{Y{{b}^{3+}}}}, $
