Which pair has 1 electron in its 's' orbital?
Correct answer: B. Na and Cr
- A. Li and Fe
- B. Na and Cr
- C. K and Mn
- D. H and He
Explanation
- Sodium (Na) has 11 electrons in its electron configuration [1s² 2s² 2p⁶ 3s¹]. One electron occupies the 's' orbital. - Chromium (Cr) has 24 electrons in its electron configuration [1s² 2s² 2p⁶ 3s² 3p⁶ 4s¹ 3d⁵]. In the case of chromium, the electron configuration shows that one electron occupies the 's' orbital.
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