The correct electronic configuration of Cr is:
Correct answer: D. [Ar] 4s13d5
- A. [Ar] 4s23d4
- B. [Ar] 4s23d5
- C. [Ar] 4s13d4
- D. [Ar] 4s13d5
Explanation
The atomic number of Cr is 24. Its electronic configuration is as follows;[Ar]4s13d5If we follow the AufBau principle, it should have been 4s23d4 because the 4s orbital will be filled completely first. However, half filled d orbital is more stable, hence, 3d4 would become 3d5 by taking an electron from 4s and it would gain stability. Hence, option D is the correct option.
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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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