Yuck! It's so tiring to try to understand band theory qualitatively
Why don't metallic solids have energy gaps? The larger the degree to which atomic orbitals overlap, the greater the energy difference between bonding and nonbonding molecular orbitals. However, the overlap degree of metals seems to be larger than that of nonmetals (the orbitals of metallic atoms are diffuse)...Is that only because electrons share more orbitals in metals?
What does this sentence mean?
"A semi-metal is defined as a material where the full and empty bands of molecular orbitals coincide in energy but with 0 energy levels per unit energy increment
In what case do bands "overlap?" Aren't these bands produced by overlap of atomic orbitals? Why, then, do they overlap again?
Thank you very very much!!!!!