Ionic Compounds

• When a metal, which has a tendency to lose electrons, combines with a nonmetal, which has a tendency to gain electrons, one or more electrons transfer from the metal to the nonmetal, creating positive and negative ions that are attracted to each other.
• A compound composed of a metal and a nonmetal is considered ionic.
• The basic unit of ionic compounds is the formula unit.
• Unlike molecular compounds, ionic compounds do not contain individual molecules but rather cations and anions in an alternating three-dimensional array.