Here's why:
* Sodium (Na) is a metal and has one valence electron (electron in its outermost shell). It readily loses this electron to achieve a stable electron configuration. This forms a positively charged sodium ion (Na+).
* Chlorine (Cl) is a nonmetal and has seven valence electrons. It readily gains an electron to achieve a stable electron configuration. This forms a negatively charged chloride ion (Cl-).
* The oppositely charged ions (Na+ and Cl-) are attracted to each other due to electrostatic forces. This electrostatic attraction between the oppositely charged ions is what constitutes the ionic bond.
So, the process of bond formation between sodium and chlorine involves the transfer of an electron from sodium to chlorine, resulting in the formation of a stable ionic compound, sodium chloride (NaCl).
