Since metals are neutral, and their electrons delocalized, is the number of electrons in a metallic solid equal to the number of protons in the solid? Also I am guessing that the valence shells of the metals are not complete? I am confused on this regard. Furthermore, I can see how the myriad molecular orbitals in metallic solids form a continuum for electrons to travel within throughout the solid, but how exactly do network solids such as silicon have conduction orbitals? Are the the MOs in silicon solid also as closely spaced as to form a continuous orbital for electrons to travel within? It just doesn't seem like the tetrahedral shape of a silicon bonds in the solid would provide MO's that are spaced closely enough to form the bands seen in metallic solids.