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What Causes Lightning?


Grade Range
Group Size
2-3 students
Active Time
60 minutes
Total Time
60 minutes
Area of Science
Key Concepts
Static electricity, electric fields, electric charges, triboelectric effect
Svenja Lohner, PhD, Science Buddies
Video narration by Jennifer E Paz
Free for a limited time thanks to individual donors


Lightning is a powerful display of static electricity in nature. But what is static electricity? In this lesson, students will learn about static electricity and electric fields by building a device that can detect electrical charges, called an electroscope. They will use their electroscope to investigate how well different materials can build up electric charges by rubbing them against wool. During their experiments, students will be able to demonstrate how electric fields exert forces on objects close by.

Learning Objectives


Per group:

Per student:

Prep Work

  • Print out a worksheet for each student.
  • Select additional materials you want the students to test. Possible materials are wood, other plastic objects, glass, or rubber.
  • If you bought a spool of copper or brass wire, cut the wire into 12-inch pieces. One piece for each student group.
  • Note: This experiment works best in a dry environment. If it is too humid, the experiment won't work as well. Humidity in the air makes the air more conductive and able to absorb excess charges. As a result, objects won't hold static charges well in a humid environment. An ideal relative humidity for electrostatic buildup is below 40 percent. Between 40 and 60 percent, a charge buildup is still possible but at a significantly reduced level.

Prep Work ()

Engage (11 minutes)

Explore (44 minutes)

Reflect (5 minutes)



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