Which monatomic ion has a charge of 1 - and the condensed electron configuration [ne]3s23p6?

An ion is an atom in which the total number of electrons is not the same with the total number of protons, giving it a net positive or negative electrical charge.

The electron configuration of chlorine is [Ne]3s23p5. If a chlorine atom adds an electron to form the chloride ion (Cl-), it will have an electron configuration of [Ne]3s23p6. While Argon has no charge.