Ionic bonding occurs between charged particles. These may be atoms or groups of atoms, but this discuss will be conducted in terms of single atoms. Ionic bonding occurs between metal atoms and nonmetal atoms. Metals usually have 1, 2, or 3 electrons in their outermost shell. Nonmetals have 5, 6, or 7 electrons in their outer shell. Atoms with outer shells that are only partially filled are unstable. To become stable, the metal atom wants to get rid of one or more electrons in its outer shell. Losing electrons will either result in an empty outer shell or get it closer to having an empty outer shell. It would like to have an empty outer shell because the next lower energy shell is a stable shell with eight electrons.
Polyatomic Ions are groups of two or more elements that have a charge associated with them as a group. They can in turn then bond to other elements or polyatomic ions to form more complex structures.
Rule 1. The cation is written first in the name; the anion is written second in the name.
Rule 2. When the formula unit contains two or more of the same polyatomic ion, that ion is written in parentheses with