This spooky bloody current trick will amaze your friends and teach them about ions and electricity. By dissolving household salt in water, ions can move through water. The movement of the ions carries a charge that can illumine a light bulb. Grab the supplies that you need and try this fascinating experiment.
What You'll Need:
- Measuring spoons
- 3 bowls
- Red food coloring
- Mixing spoon
- 3 insulated wires (about 5 to 7 inches long), stripped at both ends (ask an adult for help)
- Flashlight bulb and bulb holder
- 2 D batteries
Step 1: Place about 5 teaspoons salt in one bowl. Put 6 drops red food coloring into 1 tablespoon water in another bowl, and then pour it over the salt. Mix.
Step 2: Set up the electric circuit by referring to the diagram and steps below.
Step 3: Attach wire A and wire B to the two terminals of the light bulb holder (with light bulb attached).
Step 4: Tape the free end of wire B to the positive end of the first battery. Place the other battery's positive end next to the first battery's negative end.
Step 5: Tape wire C to the negative end of the second battery. Be sure batteries are touching each other.
Step 6: Test your circuit by touching the free ends of wires A and C, which should cause the bulb to light. If not, fix your circuit, then go on.
Step 7: Bend the free ends of wires A and C over the third bowl. Fill the bowl with water until the wires are well below the surface of the water. The light bulb will not light because water is a poor conductor of electricity.
Step 8: Now have friends come over. Show them the setup. Ask them if they know who Frankenstein's monster was. The monster was "born" when electricity brought him to life. Show them the red salt, and tell them it is dried monster blood.
Step 9: Pour the red salt into the water, and stir. As the salt dissolves, the light comes on!
For more fun science projects for kids, check out:
ABOUT THE DESIGNERS
Bloody Current by Peter Rillero, Ph.D.
Peter Rillero, Ph.D. is the Department Chair of Secondary Education and associate professor of science education at Arizona State University in Phoenix. He is the author of Time for Learning: Science; Time for Learning: The Human Body, and Totally Creepy Bugs, and the co-author of the best selling high school biology textbook in the United States. Rillero has conducted two program evaluations of the world's largest science fair, the Intel International Science and Engineering Fair. Visit Dr. Rillero's Web site.
Computer Illustration by: Rémy Simard