Which solid would you expect to have little or no band gap? a. Cu(s) b. Si(s) c. As(s)

Verified step by step guidance

1. Understand the concept of band gap: The band gap is the energy difference between the valence band and the conduction band in a solid. A small or no band gap indicates that electrons can easily move from the valence band to the conduction band, making the material a good conductor.
2. Identify the types of solids: Metals typically have little or no band gap, semiconductors have a moderate band gap, and insulators have a large band gap.
3. Analyze the given options: (a) Cu(s) is a metal, (b) Si(s) is a semiconductor, and (c) As(s) is a metalloid.
4. Recall that metals, like Cu(s), have overlapping valence and conduction bands, resulting in little or no band gap.
5. Conclude that the solid expected to have little or no band gap is the metal, Cu(s).

Key Concepts

Band Gap

The band gap is the energy difference between the valence band and the conduction band in a solid material. It determines the electrical conductivity of the material; a small or nonexistent band gap allows electrons to move freely, making the material a good conductor. In contrast, a large band gap typically indicates an insulator or semiconductor.

Conductors vs. Semiconductors vs. Insulators

Materials are classified based on their ability to conduct electricity. Conductors, like metals, have little to no band gap, allowing electrons to flow easily. Semiconductors, such as silicon, have a moderate band gap that can be overcome under certain conditions, while insulators have a large band gap, preventing electron flow under normal circumstances.

Metallic Properties of Copper

Copper (Cu) is a metal known for its excellent electrical conductivity due to its very small or nonexistent band gap. In metallic solids, the electrons are delocalized, allowing them to move freely throughout the structure, which is why copper is often used in electrical wiring and components.