? Science with Sarah: Dough-y Circuits! ??

? Watch the video of Sarah’s school science experiment here!

Hello parents, teachers and students! Are you looking for something fun to do at home that has a little bit of science behind it? Learn about electrical conductivity and circuits with Meteorologist Sarah Spivey and her awesome assistant, David Sears! In this experiment, your student will make a hypothesis about whether sugar dough or a salt-based dough conducts electricity. Then, they will make circuits out of the dough, troubleshooting until the LED lights up!

Be sure to check out GMSA@9 on Wednesdays when Meteorologist Sarah Spivey does the demonstrations and explains the science behind it.

Science with Sarah: Invite KSAT to your school for live science experiments. (KSAT)

HERE’S WHAT YOU’LL NEED

Homemade dough

1.5 cups flour

0.5 cup sugar

3 tbsp. vegetable oil

0.5 cup *distilled* water (it’s important that the water is distilled. Tap water may interfere with the experiment)

Play-doh

9v “D” battery connectors (LIKE THESE or THESE)

9v “D” Batteries (LIKE THESE)

Mini LEDs (LIKE THESE)

DO THE EXPERIMENT

STEP 1: Start by making the dough. Combine the flour, sugar, oil, and water in a bowl. If the dough is too sticky, add a little extra flour.

STEP 2: Figure out whether the homemade dough is conductive. In order to do this, take two small globs of the homemade dough and place them around the wires of the LED. Take note of which side is positive and which side is negative. The positive wire of the LED is the longer one. Then, with the battery connector attached to the battery, put the positive (red) and negative (black) wires into their respective globs of dough. Does the LED light up?

STEP 3: Repeat step 2 with the Play-doh instead of the homemade dough.

STEP 4: Now that you know which dough conducts electricity, try and make fun shapes out of your circuit!

HOW IT WORKS

When doing this experiment, your student learns which dough is conductive and which dough is inductive. The Play-doh is conductive because it contains lots and lots of salt. Salt transports electricity easily.

If you happen to use tap or bottled water instead of distilled water for the homemade dough, you may find that the LED lights up. That’s because tap or bottled water can contain minerals which may actually conduct electricity.

As your student is making different shapes with the conductive dough, they’ll be able to troubleshoot. Note that if the two sides of the dough touch, the circuit will break and the LED will not light up.