Metallic boning is the electrostatic attraction between delocalized electrons, called conduction electrons, and the metallic nuclei within metals. Because it involves the sharing of free electrons among a lattice of positively-charged metal ions, metallic bonding may be compared to that within molten salts. The metallic bond accounts for many physical characteristics of metals, such as strength, malleability, ductility, conduction of heat and electricity, and lustre.