The chlorine (CI) has 7 valence electrons. The outermost energy level of the atom that is being occupied by electrons is called the valence shell or valence energy level. Moreover, the electrons used to form bonds with the other atoms is called the valence electrons. The 7 electrons that are found in the valence shell are the electrons used to bond with the other atoms. Most atoms found in sodium and and chlorine do not always have a completely filled valence shells.