1s² 2s² 2p⁶ 3s² 3p⁵
Here's how to understand it:
* 1s²: The first energy level (n=1) has one subshell (s) which can hold 2 electrons.
* 2s²: The second energy level (n=2) has one s subshell which can hold 2 electrons.
* 2p⁶: The second energy level also has a p subshell which can hold 6 electrons.
* 3s²: The third energy level (n=3) has one s subshell which can hold 2 electrons.
* 3p⁵: The third energy level also has a p subshell that is only partially filled with 5 electrons (it can hold 6).
This configuration shows the arrangement of chlorine's 17 electrons in their respective energy levels and subshells.
