An Allegory is used to tell a story that has characters, a setting, as well as other types of symbols, that have both literal and figurative meanings.
Chlorine is counted among this group along with hydrogen (H 2), iodine (I 2), bromine (Br 2), oxygen (O 2), nitrogen (N 2) and fluorine (Fl 2). With seven electrons in its outermost orbit--one electron short of a stable eight-- the element chlorine exists in nature as a diatomic molecule. This arrangement allows two chlorine atoms to share their outermost orbit electrons, achieving stability, compared to the single atom.
As the illustration of the chlorine atom above demonstrates, the orbit closest to the chlorine nucleus holds no more than two electrons, and the next two orbits can hold a total of eight electrons each. Importantly, the most stable electron arrangement of any orbit is a full orbit.