Summer Science Series: Does Water Conduct Electricity?

Why should you get out of the pool during lighting? Find out!

We continually remind pool kiddos to vacate the water at the first sign of lightning or not to touch a switch with wet hands. Most of them don’t understand why but this experiment may shed some light on just how important it is. We’re going to find out that ‘pure’ water doesn’t actually conduct electricity, but that most water (like that in a pool) isn’t pure and once you have salt, sugar, or other impurities in the water it’s conductivity increases. Let’s get started! 

You’ll need: 

1 Light Emitting Diode (LED) (Click Here) (Do you have one leftover from Play Dough Circuits?)
2 Small Button Batteries
Copper Wires
Electrical Wires with Alligator Clips
Tape
Tap water
Distilled water (you can use bottled or make your own)
Small Container
1 Teaspoon Salt
1 Teaspoon Sugar
Spoon

Directions:

Step 1. Fill the small container with water from the tap/faucet.

Step 2. Now we’ll create our open simple circuit. Stack the two button batteries together facing the same direction so that + on one battery is touching the – on the other.

Step 3. Take your electrical wire and place one on the top of the batteries and another on the bottom. Now tape them together. 

Step 4. Now connect one wire to one leg of the LED light.

Step 5. Connect one of your alligator clips to the other leg of the LED light. Clip the opposite end of the alligator clip to your cup with water, make sure the water touches the metal clip. 

Step 6. Connect another alligator clip to the other wire coming from your battery pack. Now you have an open circuit. (It’s not connected and therefore not a closed circuit.) 

Step 7. Connect the loose end of the alligator clip to the container with water making sure the water touches the metal clip. This closes the circuit and your LED should light up!  

Step 8. Disconnect your alligator clips from your water cup. Replace the tap water with distilled water and reconnect your clips. Does the LED light up? No, because it does not conduct electricity. (If yours does, that means the “distilled water” used is not pure enough. Try a different brand of bottled distilled water or make your own.)

Step 9. Disconnect your alligator clips from the container. Sprinkle a teaspoon of salt into your distilled water and stir gently. Reconnect your alligator clips. Does the LED light up? Yes, because the salt dissolved in the water has increased its conductivity. 

Step 10. Disconnect your alligator clips from the container. Empty the water, rinse and dry your cup. Refill your container with distilled water and a teaspoon of sugar. Gently stir. Reconnect your alligator clips. Does the LED light up? No, because sugar can’t contribute ions to the water so it doesn’t increase the conductivity. 

What’s that got to do with electricity?  An electric current is conducted by a flow of electrical charges such as electrons or ions. Pure water contains very few ions and so it is a poor conductor of electricity. When impurities that can contribute ions such as salt dissolve in water, the resulting solution is a great conductor of electricity. Tap water is such a solution. Most water we come into contact with, such as tap water or not completely distilled bottle water, contains enough impurities to turn water into a conductor. This means if you touch a switch with wet hands or swim in a pool that is struck with lighting the water will conduct electricity and you will be injured. 

We hope you enjoyed the project!

Disclaimer and Safety Precautions: Kcesinc.com has provided this science activity idea for informational purposes only. Kcesinc.com does not make any guarantee or representation regarding such ideas and is not responsible or liable for any loss or damage, directly or indirectly, caused by your use of such information. Warning is hereby given that not all activities are appropriate for all individuals or in all situations. Implementation should be undertaken only in appropriate settings and with appropriate parental or adult supervision. Reading and following the safety precautions of all materials used in an activity is the sole responsibility of each individual. By accessing the science activity ideas on kcesinc.com, you waive and renounce any claims against Kcesinc.com that arise thereof.