Which item is listed as a common conductor other than salt water?

• A. Lemon juice
• B. Steel
• C. Plastic
• D. Rubber

Answer: (A)

Electricity can flow through materials that can carry charge, either by free electrons in metals or by ions in electrolytes. Lemon juice acts as an electrolyte because it contains dissolved acids and minerals that form ions, which move and carry current when placed in a circuit. That makes lemon juice a common conductor besides salt water. Plastic and rubber act as insulators and don’t allow charge to move, while steel is a metal conductor, but the example here highlights a familiar liquid conductor other than salt water, namely lemon juice.