How to Test Which Materials Conduct Electricity

A safe, simple science experiment to discover which household materials conduct electricity using basic supplies.

  1. What You'll Need. Gather these simple materials: 1 battery (AA or D-cell), 2 pieces of insulated wire (about 6 inches each), 1 small LED light bulb or flashlight bulb with holder, electrical tape, and various test materials like coins, paper clips, rubber bands, plastic spoons, aluminum foil, wooden pencils, keys, fabric, and paper. You can find most of these items around your house.
  2. Build Your Simple Circuit Tester. Strip about half an inch of plastic coating from both ends of each wire using scissors (adults should handle this step). Tape one wire to the positive end of the battery and connect the other end to one side of the light bulb holder. Tape the second wire to the negative end of the battery, leaving the other end free. You now have one loose wire end and one connection point on the light bulb holder to test materials between.
  3. Safety First. Only use batteries for this experiment - never plug anything into wall outlets. Make sure the wires don't touch each other unless you're testing a material. If the battery gets warm, take a break. Keep small materials away from very young children who might put them in their mouths. Adult supervision is recommended for all ages.
  4. Testing Materials. Touch both loose ends of your circuit (the free wire and the bulb connection) to each material you want to test. If the light bulb glows, the material conducts electricity. If it doesn't light up, the material is an insulator. Test one item at a time and have your child predict whether each material will light the bulb before testing.
  5. Recording Your Results. Create two columns on paper: 'Conductors' (materials that lit the bulb) and 'Insulators' (materials that didn't). Most metals like coins, keys, and aluminum foil will be conductors. Materials like plastic, rubber, wood, and paper will be insulators. This visual record helps children see patterns in the results.
  6. Understanding What Happened. Explain that electricity is like water flowing through a pipe - it needs a complete path to travel. Conductors allow electricity to flow through them easily, completing the circuit and lighting the bulb. Insulators block the flow of electricity, breaking the circuit. This is why electrical wires are covered in plastic coating for safety.