A molecule is formed by the combination of two hypothetical atoms, X and Y. The atoms X & Y are bound together by electrovalent bonds. The atomic numbers of X and Y are 11 and 8 respectively. The molecular formula of the molecule is

In this case, atom X with atomic number 11 will lose one electron and become a positively charged ion (cation), while atom Y with atomic number 8 will gain two electrons and become a negatively charged ion (anion). 

The resulting oppositely charged ions are then held together by strong electrostatic forces, forming the ionic compound X₂Y, where two cations of X combine with one anion of Y.