Static Electricity
Static electricity includes all the phenomena associated with stationary electric
charges. Most objects have an equal number of positive charges and negative
charges, thus creating a neutral object. Positive charges are, of course, the result
of the presence of protons, and the negative charges are the result of the
presence of electrons. The number of protons in an object will almost never
change, but the number of electrons can change. If a neutral object gains
electrons, it becomes negatively charged. If it loses electrons, it becomes
positively charged.
Since protons and electrons are too small to see and too numerous to count, an
electroscope is often used to determine whether an object is charged.
1. Draw and label a diagram to represent the electroscope demonstrated by your
instructor.
2. Describe what happens when a negatively charged object is brought near the
electroscope and then moved away. Explain what is happening within the
electroscope.
3. Describe what happens when a negatively charged object touches the
electroscope. Explain what is happening within the electroscope.
4. Draw and label a diagram of the electrophorus demonstrated by your
instructor.
5. Explain how the electrophorus becomes charged.
6. Draw and label a diagram to represent the Van de Graaff generator
demonstrated by your instructor.
7. Describe what happened when your classmates came close to the Van de
Graaff generator. Describe what happened when your classmates touched the
generator. Explain why your classmates’ hair responded the way it did.