Which of the following pairs have the same electronic structure?
Correct answer: A. Ar & Cl-1
- A. Ar & Cl-1
- B. Ca & Ar
- C. Mg & Na
- D. Ag & Sn
Explanation
Ar = 1s22s22p63s23p6 Cl- = 1s22s22p63s23p6 (doing for 18 electron instead of 17 because it gained one electron/anion)
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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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