Electron configuration of Chlorine atom is

Chlorine has an atomic number of 17, meaning a neutral chlorine atom has 17 electrons. These electrons fill the available subshells in order of increasing energy:

1. \(1s\) holds 2 electrons (total: 2)
2. \(2s\) holds 2 electrons (total: 4)
3. \(2p\) holds 6 electrons (total: 10)
4. \(3s\) holds 2 electrons (total: 12)
5. \(3p\) holds the remaining 5 electrons (total: 17)

The electron configuration is therefore: \(1s^2\,2s^2\,2p^6\,3s^2\,3p^5\)

Examining the other options:

• \(1s^2\,2s^2\,2p^6\,3s^2\,3p^4\) gives only 16 electrons (this is sulphur).
• \(1s^2\,2s^2\,2p^6\,3s^2\,3p^6\) gives 18 electrons (this is argon).
• \(1s^2\,2s^2\,2p^5\,3s^2\,3p^6\) gives 17 electrons but violates the aufbau principle - the \(2p\) subshell must fill completely (6 electrons) before the \(3s\) subshell begins.