Which is an example of a semiconductor?

• A. Copper
• B. Neon
• C. Gold
• D. Germanium

Answer: (D)

Semiconductors are materials whose ability to conduct electricity sits between that of metals and insulators, and this conductivity can be adjusted by factors like impurities (doping), temperature, or light. Copper and gold are metals and conduct electricity very well, while neon is a noble gas that doesn’t conduct under normal conditions. Germanium, on the other hand, is a metalloid with a conductivity that can be tuned, and it’s widely used in semiconductor devices because its electronic properties allow controlled conduction in diodes and transistors. That tunable, intermediate conductivity is what makes germanium a classic example of a semiconductor.