Static Science: How Well Do Different Materials Make Static Electricity?
Have you ever noticed that some types of clothes are more susceptible to static cling than others? For example, a wooly sweater can have a lot of static cling, but clothing made out of cotton doesn’t get static cling nearly as much. How well do other materials around the house produce static electricity? In this science activity, you’ll explore this by making a simple, homemade electroscope and testing it out. The results may shock you!
This activity is not appropriate for use as a science fair project. Good science fair projects have a stronger focus on controlling variables, taking accurate measurements, and analyzing data. To find a science fair project that is just right for you, browse our library of over 1,200 Science Fair Project Ideas or use the Topic Selection Wizard to get a personalized project recommendation.
Static electricity is the build-up of electrical charge on an object. This charge can be suddenly discharged (such as when a lightning bolt flashes through the sky), or it can cause two objects to be attracted to each other. Socks fresh out of the dryer that cling to each other are a good example of this attraction in action. Specifically, static cling is an attraction between two objects with different electrical charges, positive and negative.
Static electricity can be created by rubbing one object against another object. This is because the rubbing releases negative charges, called electrons, which can build up to produce a static charge. For example, when you shuffle your feet across a carpet, electrons can transfer to you, building up a static charge on your skin. You can suddenly discharge the static charge as a shock when you touch a friend or some objects.
While objects that have opposite charges are attracted to each other (like clingy, freshly-dried socks), objects that have the same charge are actually repelled by each other. This principle is used in making an electroscope, which is a scientific instrument that detects electrical charges.
Extra: Use your homemade electroscope to test even more materials. Which ones can hold a static charge and which can’t?
Extra: You can use your electroscope to investigate which materials conduct the most static electricity. This is because the further the aluminum ball moves from the aluminum pan, the bigger the charge from the test material is. Which common household materials can become the most electrically charged, and which ones become the least charged?
Extra: Some objects become negatively charged and other objects become positively charged with static electricity. Try to discover a way to investigate this. Does this kind of electroscope detect both types? How can you tell the difference between the two?
Extra: Static electricity is not good when it gets in your clothes! Try an experiment rubbing an object with a dryer sheet (like Bounce) after rubbing the object against a balloon. How do dryer sheets work? What happens to the electroscope reading after rubbing a charged object against a dryer sheet? How do different dryer sheet products compare?
Observations and Results
Did the aluminum ball on the electroscope move away from the pan when you placed the electroscope on the charged Styrofoam plate? Did the other material you tested behave similarly, or not move the ball at all?
When an object, like the Styrofoam plate, gets an electrical charge, it can be either positive or negative. (If an object has a lot of electrons, it can have a negative charge, but if it does not have many electrons, it can have a positive charge. Whether an object tends to gain or lose electrons depends on the type of material it’s made out of.) When a charged object (like the charged Styrofoam plate) touches the aluminum pan of the electroscope, the charge (or electrons) easily moves through the metal pan. Since the aluminum ball is touching the pan, the ball gets the same charge as the pan. This means that both the ball and pan have the same charge (they are either both positively or negatively charged). Because objects that have the same charge are repelled by each other, the ball is pushed away from the pan. Materials that tend to gain or lose electrons include wool, human hair, dry skin, silk, nylon, tissue paper, plastic wrap and polyester, and when testing these materials you should have found that they moved the aluminum ball similarly to how the Styrofoam plate did.
More to Explore
Teisha Rowland, PhD, Science Buddies
Science Buddies |
Electricity, materials, conductivity
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