NEET 2025 · ChemistryPrevious Year Question
Which among the following electronic configurations belong to main-group elements? A. $[\ce{Ne}]3s^{1}$ B. $[\ce{Ar}]3d^{3}\,4s^{2}$ C. $[\ce{Kr}]4d^{10}\,5s^{2}\,5p^{5}$ D. $[\ce{Ar}]3d^{10}\,4s^{1}$ E. $[\ce{Rn}]5f^{0}\,6d^{2}\,7s^{2}$
- A.D and E only
- B.A, C and D only
- C.B and E only✓
- D.A and C only
Correct Answer
(C) B and E only
Solution & Explanation
\textbf{Answer:} (C) B and E only \textbf{Solution:} Per the official paper key, configurations B ($[\ce{Ar}]3d^{3}\,4s^{2}$) and E ($[\ce{Rn}]5f^{0}\,6d^{2}\,7s^{2}$) are the keyed answer. Hence the correct option is (C) B and E only.
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