Metal, copper, and water are __________ of electricity.

• A. Conductors
• B. Nonconductors
• C. Insulators
• D. Amps

Answer: (A)

Electric current flows most easily through materials that allow charged particles to move freely. Metals do this well because their atoms release a cloud of free electrons that can drift when voltage is applied, making them good conductors. Copper is a prime example of a metal with very high conductivity, so it’s a classic conductor. Water conducts electricity because it usually contains dissolved minerals and salts that form ions; those ions move and carry charge, allowing current to pass. Pure distilled water, on the other hand, has few ions and acts more like a poor conductor. Substances that resist movement of charge, such as dry wood or plastic, are insulators. The term amperes, or amps, is a unit of current, not a material, so it doesn’t describe a conductor.