All chemicals are formed by atoms of chemical elements. Scientists have observed that the vast majority of known substances consist of combined atoms together. Sometimes they are atoms of the same element, sometimes of different elements.
Of the millions of known substances, only six are known to contain unmatched atoms. These substances are helium, neon, xenon, argon, krypton and radon, gases present in small quantities in the earth's atmosphere. These gases are formed by non-combined atoms of the elements of the group. 18 of the periodic table (He, NE, Ar, Kr, Xe, RN), called the noble gas group.
Moreover, to this day no natural substance has been discovered in which noble gas atoms are combined with each other or with atoms of other elements.
These observations provided clues to scientists in the late nineteenth and early twentieth centuries to begin to clarify how atoms combine. Since the electrosphere is the outermost part of atoms and the nucleus is very small, it seems reasonable to be the electrosphere that acts on the combination of atoms. And since noble gases tend not to combine, it seems that having a noble gas-like electrosphere allows an atom to stabilize.