A stable arrangement of eight valence electrons : ³⁵Cl⁻¹
<h3>Further explanation</h3>
Chlorine is a halogen gas, located in group 17, p block
Chlorine has an atomic number of 17 and an atomic mass of 35
Electron configuration: [Ne] 3s²3p⁵
If we look at the electron configuration, then Cl will bind 1 more electron so that the configuration is stable like Argon (atomic number 18)
So by binding this one electron, chlorine forms negative ions (anions)
³⁵Cl⁻¹
B. Cl⁻² binds 2 electrons, exceeding the octet rule
C. Cl⁺¹, releases 1 electron, remains unstable
D. Cl, the neutral form of Cl, is still unstable with a 7-electron valence configuration