The type of bonding present in the crystal structure of sodium chloride is ionic bonding. Ionic bonding occurs when there is a transfer of electrons between atoms, resulting in the formation of positively charged cations and negatively charged anions. These ions are then attracted to each other due to their opposite charges, forming an ionic bond.In the case of sodium chloride NaCl , sodium Na has one electron in its outermost shell, while chlorine Cl has seven electrons in its outermost shell. Sodium tends to lose its one valence electron to achieve a stable electron configuration, similar to that of the nearest noble gas, neon. When sodium loses this electron, it becomes a positively charged ion Na+ .On the other hand, chlorine needs one more electron to complete its outermost shell and achieve a stable electron configuration, similar to that of the nearest noble gas, argon. Chlorine gains the electron lost by sodium, resulting in a negatively charged ion Cl- .The electrostatic attraction between the positively charged sodium ion Na+ and the negatively charged chloride ion Cl- forms the ionic bond in the crystal structure of sodium chloride. This ionic bond results in a stable crystal lattice structure, where each sodium ion is surrounded by six chloride ions, and each chloride ion is surrounded by six sodium ions.