The physical and chemical properties of metals are consistent with the idea that the electrons in these materials are highly mobile. They are, for example, good conductors of electricity, and they easily lose electrons to form positive ions. The high thermal conductivity of metals can be explained by postulating frequent collisions between electrons. And the shiny surfaces of metallic solids are consistent with the loosely held electrons being able to absorb and emit light over a wide range of wavelengths.

In the electron sea model of metallic bonding, the metallic lattice is represented as a regular array of positive ions, i.e., metal atoms minus their valence electrons, with the valence electrons wandering relatively undisturbed through the lattice. Although they are slowed down in the presence of a positive ion, the electrons are able to avoid becoming trapped by these positive centers. The strong attractive forces...