Metallic Bond
Definition
The bond in metals: positive metal ions sitting in a sea of freely moving electrons. It explains why metals conduct electricity and can be bent without breaking.
Technical definition
Metallic bonding is the delocalized sharing of valence electrons among a lattice of positive metal cations, described by the sea-of-electrons model. This electron mobility accounts for metals' high electrical and thermal conductivity, malleability, ductility, and luster.
Example
Copper wire conducts electricity because its delocalized electrons flow freely through the metal lattice when voltage is applied.
Common confusion
Metallic bonding is not just ions stuck together. The delocalized electrons are the glue, and removing them, as in isolated metal ions, destroys the metallic properties.