the most common type of ionic bonding is seen in compounds of metals and nonmetals (except noble gases, which rarely form chemical compounds). metals are characterized by having a small number of electrons in excess of a stable, closed-shell electronic configuration. as such, they have the tendency to lose these extra electrons in order to attain a stable configuration. this property is known as "electropositivity". non-metals, on the other hand, are characterized by having an electron configuration just a few electrons short of a stable configuration. as such, they have the tendency to gain more electrons in order to achieve a stable configuration. this tendency is known as "electronegativity". when a highly electropositive metal is combined with a highly electronegative nonmetal, the extra electrons from the metal atoms are transferred to the electron-deficient nonmetal atoms. this reaction produces metal cations and nonmetal anions, which are attracted to each other to form a "salt".