What is the electron configuration of a neutral sodium atom (atomic number 11), and what ion does it form?
Answer and explanation
Correct answer: A. Configuration 2,8,1; forms Na+ cation with stable octet 2,8 by losing one valence electron
- Step 1: Sodium has 11 electrons: 2 in the first shell, 8 in the second, and 1 in the outer valence shell (2,8,1). Step 2. It readily loses this single valence electron to achieve a stable full outer shell (octet 2,8), forming the Na+ ion. Answer: Configuration 2,8,1; forms Na+ cation with stable octet 2,8 by losing one valence electron. Why not the others: Gaining 7 electrons is energetically unfavourable compared to losing 1.
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