Pairs of elements | D and f Block Elements | JEE MAIN 2026

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JEE MAIN_2026

04-04-26_S2

Question

Pairs of elements with the same number of electrons in their respective 4 f orbital are [Atomic number. Eu-63, Gd-64, Dy-66, Ho-67, Tm-69, Yb-70, Lu-71, Hf-72] A. (Eu and Gd) B. (Dy and Ho) C. ( Yb and Hf ) D. (Lu and Tm) Choose the correct answer from the options given below:

Select the correct option:

A

B and C Only

B

A and B Only

C

A and D Only

D

A and C Only

✓ Correct! Well done.

✗ Incorrect. Try again or view the solution.

Solution

$\begin{aligned} & G d-[\mathrm{Xe}] 4 \mathrm{f}^7 5 \mathrm{~d}^1 6 \mathrm{~s}^2 \\ & \mathrm{Eu}-[\mathrm{Xe}] 4 \mathrm{f}^7 6 \mathrm{~s}^2 \\ & \mathrm{Dy}-[\mathrm{Xe}] 4 \mathrm{f}^{10} 6 \mathrm{~s}^2 \\ & \mathrm{Ho}-[\mathrm{Xe}] 4 \mathrm{f}^{11} 6 \mathrm{~s}^2 \\ & \mathrm{Hf}-[\mathrm{Xe}] 4 \mathrm{f}^{14} 6 \mathrm{~s}^2 5 \mathrm{~d}^2 \\ & \mathrm{Yb}-[\mathrm{Xe}] 4 \mathrm{f}^{14} 6 \mathrm{~s}^2 \\ & \mathrm{Lu}-[\mathrm{Xe}] 4 \mathrm{f}^{14} 5 \mathrm{~d}^1 6 \mathrm{~s}^2 \\ & \mathrm{Tm}-[\mathrm{Xe}] 4 \mathrm{f}^{13} 6 \mathrm{~s}^2\end{aligned}$

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