Which term describes a material that conducts electricity easily?

• A. Electrical conductor
• B. Electrical insulator
• C. Semiconductor
• D. Dielectric

Answer: (A)

Electrical conductor is the term for a material that conducts electricity easily. This happens because conductors have many free charge carriers—electrons that aren’t bound tightly to atoms and can move when a voltage is applied. In metals, these electrons form a flexible “sea” around the positively charged nuclei, so applying a potential difference lets them flow with little resistance, giving high conductivity. Insulators, by contrast, hold onto their electrons tightly, presenting a large barrier to electron movement and thus high resistance. Dielectrics are a type of insulator used to store charge by polarizing in an electric field rather than by carrying current. Semiconductors conduct electricity too, but not as readily as metals; their conductivity can be controlled with temperature, light, or impurities.