Experiment with Salt Water Conductivity

3.8 based on 90 ratings
Updated on Mar 28, 2014

Does salt water conduct electricity? As a matter of fact, it does! In this science experiment, your child will build a mini circuit and test it in both salt water and fresh water. It's a simple experiment, but it will show how salt water acts as a conductor to electrical currents while reinforcing important lessons about conductivity and electricity.

What You Need:

  • Masking tape
  • 9-volt battery
  • Buzzer (can be bought at an electronics store)
  • 2 craft sticks
  • Aluminum foil
  • Water
  • Salt water

What You Do:

  1. First, have your child cover both craft sticks with aluminum foil.
  2. Take the buzzer and tape the red wire to the positive end of the battery (the + sign).
  3. Tape one foil-covered craft stick to the black wire. Tape the other one to the negative side of the battery (the - sign).
  4. Test your buzzer by touching the two sticks together, which should make the buzzer sound. If it doesn’t work, make sure that everything is taped together correctly.
  5. Now, ask your child to position the tips of the metal sticks in the salt water so they're about an inch apart. Make sure the two sticks don’t touch. The salt water will act like a wire connecting the metal sticks and complete the circuit to make the buzzer go off.
  6. Try the experiment in the fresh water. Why does your child think that the buzzer sounded in the salt water but not in the fresh water?

What Happened? The salt dissolves into the water and breaks down into "ions," which act as a conductor. Fresh water does not have these ions, therefore it cannot conduct the electrical current.