Which one of the following substances is not a semiconductor material used in electronics?

Introduction / Context:
This question comes from basic electronics and solid state physics. Semiconductor materials are extremely important in making diodes, transistors and integrated circuits. Common semiconductor materials include silicon, germanium and gallium arsenide. The question asks you to identify which listed material is not classed as a semiconductor in typical electronic applications.

Given Data / Assumptions:

• The options include silicon, germanium, quartz, gallium arsenide and silicon carbide.
• We are asked to pick the one that is not a semiconductor.
• Assume standard electronic materials classification at room temperature.

Concept / Approach:
Silicon and germanium are classic elemental semiconductors. Gallium arsenide is a compound semiconductor used in high speed and optoelectronic devices. Silicon carbide is also used as a wide band gap semiconductor in high power electronics. Quartz is crystalline silicon dioxide and is typically an insulator or dielectric, not a semiconductor. While quartz is used in electronic circuits as a piezoelectric crystal, it does not conduct like a semiconductor. Therefore, quartz is the material that is not a semiconductor among the options.

Step-by-Step Solution:

Verification / Alternative check:
Electronics textbooks list silicon, germanium, gallium arsenide and silicon carbide under semiconductor materials and describe their band structures in detail. Quartz, on the other hand, appears in discussions of dielectric materials and piezoelectric crystals. Its electrical resistivity is much higher than that of semiconductors, and it does not form p n junctions in the same way. Practical device examples such as quartz crystal oscillators use quartz for its mechanical and piezoelectric properties but rely on other materials for semiconductor functions. This confirms that quartz is not a semiconductor.

Why Other Options Are Wrong:

• Silicon: A standard semiconductor and primary material for most microchips.
• Germanium: An elemental semiconductor historically important in early electronics.
• Gallium arsenide: A compound semiconductor used in lasers, LEDs and high frequency devices.
• Silicon carbide: A semiconductor used where high power and high temperature performance is required.

Common Pitfalls:
Some learners know that quartz is related to silicon and may assume anything containing silicon is a semiconductor. However, silicon dioxide in crystalline form behaves as an insulator, not like elemental silicon. It is also easy to assume that any material used in electronics must be a semiconductor, but many, like quartz, glass and plastics, serve as insulators or mechanical components. Separating the roles of different materials in electronic circuits helps answer such questions correctly.

Final Answer:
The substance that is not a semiconductor is Quartz.