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The Brain, Neurons and Brain Chemistry

Author(s): Nancy P. Moreno, PhD, Barbara Z. Tharp, MS, and Tadzia GrandPré, PhD

Build a Circuit

Student Activity: Sending the Signals

Part 1

1. Wrap the exposed end of one wire from the light bulb around one pole on the battery. Tape it in place with a piece of electrical tape. 

2. Attach the end of the other wire to the second battery pole and tape it in place. 

3. Test the connection by briefly touching the exposed ends of the two loose wires together. (The bulb should burn brightly.) 

4. Wrap the exposed ends of the loose wires with the aluminum foil, as shown above.

Part 2

All cells contain water, some dissolved salts and sugar. Which substances in cells help conduct electricity? You will investigate what happens when a tiny amount of electricity passes through distilled water, a saltwater solution, and a sugar-water solution.

1. You have three labeled cups of distilled water, a container of salt and a container of sugar. Pour the salt into the cup of water labeled “salt,” and stir until the salt dissolves. Pour the sugar into the cup of water labeled “sugar,” and stir until the sugar dissolves.

2. On a separate sheet of paper, or on the back of this sheet, create a chart (see sample chart, PDF) to record your predictions, reasons for your predictions, and test results for each liquid tested. 

3. What do you think will happen when you put the foil-wrapped wires in the different solutions? Record your predictions and reasons.

4. Test the first solution by inserting both foil-wrapped tips below the surface of the liquid. Keep the tips apart. Record the results. Next, test each of the other two liquids and record the results.

5. Based on your observations, which substances in cells would you say helped conduct electricity? Write a paragraph describing the steps you followed, your observations and your answers to this question.

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Funded by the following grant(s)

NIH Blueprint for Neuroscience Research Science Education Award, National Institute on Drug Abuse, and NIH Office of the Director

The Learning Brain: Interactive Inquiry for Teachers and Students
Grant Number: 5R25DA033006

Science Education Partnership Award, NIH

Filling the Gaps: K-6 Science/Health Education
Grant Number: 5R25RR013454