What is the electron configuration of C1?

The electron configuration of chlorine (Cl), with an atomic number of 17, is 1s² 2s² 2p⁶ 3s² 3p⁵. This configuration indicates that there are two electrons in the first energy level (1s), eight in the second (2s and 2p), and seven in the third (3s and 3p). Chlorine is in Group 17 of the Periodic Table, which is why it has seven valence electrons.