The chemical formula : Cl₂
Further explanation
Chlorine is a halogen gas element which has atomic number 17 which is in group 17, p block and period 3
The electron configuration of Cl : [Ne] 3s² 3p⁵ ⇒ 2, 8, 7
So the valence electron is 7, so to achieve stability you will need 1 more electron so it is stable like Argon
Cl will be covalently bonded (using shared electron pairs) with other Cl atoms to form a non-polar molecule, namely Cl₂