Formation of Ionic Bonds in NaCl

A chemical bond is formed when sodium and chlorine atom approach sufficiently to one another. Since chlorine atom has significantly higher electronegativity than sodium atom, there is a total electron transfer from the electron orbital of sodium to the one of chlorine and this forms a negatively charged chloride anion and a positively charged sodium cation which are mutually attracted. This type of coupling in which ions are formed is called an ionic bond.