CHEM101 Lecture Notes - Lecture 34: Valence And Conduction Bands, Metallic Bonding, Electrical Resistivity And Conductivity

• School: University of Alberta
• Department: Chemistry
• Course: CHEM101
• Professor: Rylan Lundgren

Document Summary

Bonding in metals cont: consider the mo of li2 then coninue adding li2 units to get lin where n is some very large number, lithium starts with a large gap between low and high energy orbitals. Adding mos together to make a large number of new molecular orbitals. Lumo: lowest unoccupied mo where electrons need to go to conduct. When a very large # of atoms combine they form mos that are called bands: mg atom: 1s2 / 2s2 / 2p6 / 3s2 (valence electrons) 3s is illed (valence band, these orbitals contribute to the valence band) 3d is also empty but it"s so high energy that it is ignored. Mg metal where n = some very large # In mg the conducion band and the valence band are overlapping (close in energy) so electrons can travel easily from the valence band to the conducion band. Conductors, semiconductors, and insulators: conductors: material that conducts electricity.