When a large number of atoms are placed together valence shell of each atom is affected as they are of comparable energies and an energy band is formed called valence band. If some energy is supplied, electrons can easily move to conduction band
aditya verma
14 Years ago
when two atoms combine then valence band is the band which is formed due to intermixing of oribitals in which outermost electron is present while conduction band is the band which is formed due to inter mixing of vacant orbitals