Chemical bonding is driven by the electrostatic attraction between positive and negative charges. This attraction holds atoms together in a variety of configurations, such as covalent bonds, ionic bonds, or metallic bonds. In covalent bonding, atoms share electrons to complete their outer shells, resulting in the formation of molecules. In ionic bonding, electrons are transferred from one atom to another, resulting in the formation of ions that attract each other and form crystalline structures. In metallic bonding, electron pooling allows for the formation of a sea of electrons that hold metal atoms together, resulting in unique properties such as ductility and electrical conductivity.