The outermost electronic configuration of 19K is:
Correct answer: D. 4s, 3p
- A. 3s, 3p
- B. 4s, 3d
- C. 3s, 3d
- D. 4s, 3p
Explanation
The full electronic configuration in order of increasing energy is as follows: 1s2, 2s2, 2p6, 3s2, 3p6, 4s1 The correct option according to this sequence and the n+l rule is D. Option B is incorrect because the 3d subshell is unoccupied by electrons in the potassium atom at ground level. Option C is incorrect because the 3d subshell is unoccupied by electrons in the potassium atom at ground level.Option A is incorrect.
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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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