Give Electronic configuration of Sodium:
Correct answer: C. 1s2,2s2,2p6,3s1
- A. 1s2,2s2,2p6
- B. 1s2,2s2,2p6,3s2
- C. 1s2,2s2,2p6,3s1
- D. None of these
Explanation
Sodium has atomic number 11, so its 11 electrons fill as 1s2, 2s2, 2p6 and then 3s1. The likely mistake is option b, which gives 3s2 and therefore represents 12 electrons, not neutral sodium.
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About Electronic Configuration
Electronic configuration describes how electrons occupy shells, subshells and orbitals around an atom. Questions use the Aufbau principle, Pauli exclusion principle and Hund's rule to write configurations, identify valence electrons, form ions and explain periodic trends, including common exceptions such as chromium and copper.
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