Metallic bonding
Metallic bonding constitutes the electrostatic attractive forces between the delocalized electrons, called conduction electrons, gathered in an electron cloud and the positively charged metal ions. Understood as the sharing of "free" electrons among a lattice of positively charged ions, metallic bonding is sometimes compared with that of molten salts; however, this simplistic analogy is useful for very few metals. In a more quantum-mechanical view, the conduction electrons divide their density equally over all atoms that function as neutral entities. Metallic bonding accounts for many physical properties of metals, such as strength, ductility, thermal and electrical conductivity, opacity, and luster. Although the term "metallic bond" is often used in parallel to the term "covalent bond", it is more precise to use the term
metallic bonding, because this type of bonding is collective in nature, and a single "metallic bond" between two definite atoms does not exist. Metallic bonding is not the only type of chemical bonding a metal can exhibit, even as a pure substance.