Name: _________________________________
Partner: _________________________________
Date _________________________________
Electrostatics and Charged Particles
Purpose: To observe the effects of static electricity in different situations.
Hypothesis: If we know that an object possesses either a positive or negative charge, then the charge
transferred to an uncharged object can be determined using the law of electric charges.
Materials:
Electroscope
Polyethylene strip
Fur
Acetate strip
Silk
Ebonite rod
Glass rod
Water
Electrostatic Series Chart (p275)
INDUCTION
1. Approach the electroscope with a negatively charged polyethylene strip. Draw pictures of the
before and after diagrams.
Instrument – After
Instrument –
Before
Leaves
together
2. Approach the electroscope with a positively charged acetate strip.
Instrument – Before
Instrument – After
Illustrate the charge by reversing all the charges
from the diagram directly above. Please show in
your work.
Leaves
together
Conduction
3. Rub the lucite (glass rod) with silk to make the rod positive and touch the top of the
spectroscope.
Instrument – Before
Instrument – After
Leaves
together
Illustrate the charge by reversing all the charges
from the diagram directly below. Please show in
your work.
Illustrate the charge
4. Rub the ebonite rod with fur to give the rod a negative charge and touch the top of the
spectroscope.
Instrument – Before
Instrument – After
5. Illustrate when a stream of water is approached by positively-charged rod and then by a
negatively charged rod. Illustrate the results.
Positive rod produced by rubbing silk and a glass
Negative rod produced by rubbing fur on an
rod.
ebonite rod. (hair on comb)
 (Greek letter)
means partial
This box should have similar pictures to the one
charge
on the left as a positive rod also has an effect on a
stream of flowing water.
Illustrate the
water molecule
with its charge
Answer the following questions in your notebook:
1.
2.
3.
4.
5.
How many methods of charging were used in this experiment? Explain. Was any method left
out? Explain.
Three methods were used
a. Friction – rubbing the two objects to get the charge, silk and glass
b. Conduction – touching the charged rod to the top of electroscope
c. Induction – approaching the charged rod to the top of electroscope
What is electricity?
Electricity – is the flow of electric charges.
What subatomic particle is involved with an electric current?
The electron is the subatomic particle involved with an electric current.
What charge will the two metals have if a positive rod is brought to the top of the electroscope?
The two metals will have positive charge as the positive rod at the top will push the electrons
away from the positive rod. There was an error on the original sheet and the question was not
completed.
What happens when two like charges (positive and positive or a negative and a negative) are put
together?
Like charges repel each other.
6. What happens when two unlike (opposite) charges are put together?
Unlike charges attract each other.
7. What happened in the case of the water molecule? What can be
determined about the water molecule in this experiment.
Water will be attracted to a charged rod. That rod can be either
positive or negative. This means that the water molecule is both
positive and negative.
8. What is the law of electric charges?
Law of electric charges says that like charges repel each other; unlike
charges attract one another; charged objects attract neutral objects;
and attractive forces depend on distance.
9. How can you tell if something is going to be positively or negatively
charged? (i.e., What do you use and how do you use it?)
The electrostatic series is used to determine what will be positive and negative. The one at the
top will be positive and the one on the bottom will be negative.
10. Why are dust particles attracted to a newly polished car?
A polished car using has a charge. Neutral dust particles are attracted to a charged object.
List 6 materials that are electrical conductors. List 6 materials that are electrical insulators.
Good conductors










Silver
Copper
Gold
Aluminum
Magnesium
Tungsten
Nickel
Mercury
Platinum
Iron
Poor conductors











Oil
Fur
Silk
Wool
Rubber
Porcelain, glass
Plastic
Wood
Paper
Wax
ebonite
11. Explain the purpose of the electrostatic series.
The electrostatic series is useful in helping us to determine and obtain a positive and/or
negative charge.
12. How would you determine an unknown charge of an object?
If the know the charge on one object, it is attracted to the opposite charge but repelled by shte
same charge.
13. Why does a charged object stick to a neutral object?
A neutral object can stick to a charged object because the charged object can force electrons
away or move them toward the charged object. .