Ionic bonds typically form between elements that have significantly different electronegativities, particularly between metals and nonmetals. In this type of bond, one atom donates electrons to another, resulting in the formation of positively and negatively charged ions.
Metals, such as sodium (Na), potassium (K), and calcium (Ca), tend to lose electrons and form positive ions (cations). On the other hand, nonmetals, like chlorine (Cl), fluorine (F), and oxygen (O), tend to gain electrons, forming negative ions (anions).
For example, when sodium (a metal) reacts with chlorine (a nonmetal), sodium loses one electron to achieve a stable electron configuration, becoming a Na+ ion. Chlorine gains that electron, becoming a Cl– ion. The electrostatic attraction between these oppositely charged ions results in the formation of sodium chloride (table salt).
In summary, elements that are located on opposite sides of the periodic table are most likely to form ionic bonds, with metals transferring electrons to nonmetals.