Ionic Bonding
Stable Electron Configuration
The atom is not stable and will not react when the highest energy level of an atom is filled with electrons.Noble gases have stable electrons The chemical properties of an element depends on the number of valance electrons. It is useful to have a model of atoms to focus on valance electrons. An electron dot diagram is a model of an atom in which each dot represents a valence electron.
Ionic Bonds
An ionic Bond is the force that holds cations and anions together. Elements that do not have complete sets of valence eletrons tend to react. Look at the figure on the left. This is an example of an ionic bond. If chlorine were to gain one valence electron it would have the same stable electron arrangement. When an atom gains or loses an electron, the number of protons is no longer equal to the number of electrons. An ion with a negative charge is an anion. An ion with a positive charge is a cation.