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.