Question

Describe the difference between the conduction band and the valence band.

A. the valence band is the group of highest energy occupied orbitals in the solid whereas the conduction band is the set of filled orbitals that are higher in energy than the valence band.
B. the valence band is the group of lowest energy occupied orbitals in the solid whereas the conduction band is the set of empty orbitals that are lower in energy than the valence band.
C. the valence band is the group of highest energy occupied orbitals in the solid whereas the conduction band is the set of empty orbitals that are higher in energy than the valence band.
D. the valence band is the group of lowest energy occupied orbitals in the solid whereas the conduction band is the set of filled orbitals that are higher in energy than the valence band.

Answer 1

The valence band consists of lower energy levels filled with electrons while the conduction band is a higher energy level that is empty in insulators but can be partially filled in conductors, facilitating electrical conductivity. The band gap is the energy difference between these bands, determining a material's electrical properties.

Step-by-step explanation:

The difference between the conduction band and the valence band in solids pertains to the energy levels and electron occupancy. The valence band comprises the energy levels that are typically filled with electrons. These are the outermost electrons, also known as valence electrons, which are tightly bound to atoms and play a key role in chemical reactions. In contrast, the conduction band is an energy level higher than the valance band, which is usually empty in insulators but can become partially filled in conductors. Electrons in the conduction band are much more loosely bound than those in the valence band and can move freely throughout the material, facilitating electrical conductivity.

A band gap represents the energy difference between the conduction band and the valence band. The size of this gap is critical as it dictates a material's ability to conduct electricity. In conductors, electrons can easily be excited to the conduction band due to a small or nonexistent band gap. Insulators have a large band gap, making electron promotion to the conduction band difficult, thereby limiting their ability to conduct electricity. Semiconductors fall between these two, with a band gap that allows some electron promotion under certain conditions, making them better conductors than insulators but not as good as conductors.