Lanthanoid ions with 4 f 7 configuration are : (A) Eu 2+ (B) Gd 3+ (C) Eu 3+ (D) Tb 3+ (E) Sm 2+ Choose the correct answer from the options given below:

Chemistry · d and f Block Elements

JEE Main 2025 — 22 January, Morning Shift — Question 30

Lanthanoid ions with $4 f^{7}$ configuration are :

(A) $\mathrm{Eu}^{2+}$ (B) $\mathrm{Gd}^{3+}$ (C) $\mathrm{Eu}^{3+}$

(D) $\mathrm{Tb}^{3+}$ (E) $\mathrm{Sm}^{2+}$

Choose the correct answer from the options given below:

${ }_{63} \mathrm{Eu}^{2+}-[\mathrm{Xe}] 4 \mathrm{f}^{7} 6 \mathrm{~s}^{0}$

${ }_{64} \mathrm{Gd}^{3+}-[\mathrm{Xe}] 4 \mathrm{f}^{7} 5 \mathrm{~d}^{0} 6 \mathrm{~s}^{0}$

${ }_{63} \mathrm{Eu}^{3+}-[\mathrm{Xe}] 4 \mathrm{f}^{6} 6 \mathrm{~s}^{0}$

${ }_{65} \mathrm{~Tb}^{3+}-[\mathrm{Xe}] 4 \mathrm{f}^{8} 6 \mathrm{~s}^{0}$

${ }_{62} \mathrm{Sm}^{2+}-[\mathrm{Xe}] 4 \mathrm{f}^{6} 6 \mathrm{~s}^{0}$

$\mathrm{Eu}^{2+} \& \mathrm{Gd}^{3+}$

Answer key and solution verified before publishing.

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