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Electron configuration of Chlorine atom is 

Chemistry
JAMB 2025

Electron configuration of Chlorine atom is 

  • A. 1S\(^2\)2S\(^2\)2P\(^6\)3S\(^2\)3P\(^5\)
  • B. 1S\(^2\)2S\(^2\)2P\(^6\)3S\(^2\)3P\(^4\)
  • C. 1S\(^2\)2S\(^2\)2P\(^6\)3S\(^2\)3P\(^6\)
  • D. 1S\(^2\)2S\(^2\)2P\(^5\)3S\(^2\)3P\(^6\)
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Correct Answer: Option A
Explanation

The electron configuration describes the arrangement of electrons within an atom's orbital shells. Chlorine (Cl) has an atomic number of 17, meaning a neutral chlorine atom has 17 electrons. The filling of electron orbitals follows the Aufbau principle (lowest energy levels first), resulting in the following configuration: 

  • 1s²: The first energy level, s-subshell, holds 2 electrons.
  • 2s²: The second energy level, s-subshell, holds 2 electrons.
  • 2p⁶: The second energy level, p-subshell, holds 6 electrons.
  • 3s²: The third energy level, s-subshell, holds 2 electrons.
  • 3p⁵: The third energy level, p-subshell, holds the remaining 5 electrons (2 + 2 + 6 + 2 + 5 = 17 electrons in total). 

There is an explanation video available below.


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Explanation Video

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