# Band theory- Is the conducting band the last orbital with a gap between the two bands?

What I understand is in each atom there are conducting and valence bands and the valence band, the minimum level for electrons (is the orbital before the last)

Is the conducting band the last orbital with a gap in between the two bands?

• I'm not sure I understand the question. The conduction band is the band above the gap above the last occupied band. Whether or not it is the last band above a gap is immaterial, although I believe that it is also true. If there were any higher gaps, the band above it would not be the conduction band, although it would be a conduction band. BTW, atoms don't have bands, and bands don't have orbitals. May 12 '18 at 12:03
• are bands in orbitals? i thought for example in a metal the last shell was both the valence and conduction bands but in semi conductors and insulators the conduction band was in the next shell (last one) May 12 '18 at 12:10
• I dont get what you mean by "atoms dont have bands" May 12 '18 at 12:11
• We don't use the language of shells and orbitals when talking about solids. Shell and orbital imply certain properties that that bands don't have, e.g. a single discrete energy, and a point symmetry. Bands have a continuum of energies, and a different kind of symmetry. It's just a matter of language semantics. Actually, you touch on this when you say that the last shell is both the conduction and valence band. When atoms are brought together, the discrete energy that the orbital has spreads out into a band, and then splits into bands. You can't identify the orbital with a band. May 12 '18 at 12:19
• then how do I know if the conduction band is above the level of the valence one? where are they located May 12 '18 at 12:54