SNC 1D1 – Physics Unit
Date: _______________________
The Electrostatic Series
How to Predict a Charge
In the previous lesson, you saw a balloon become electrostatically charged by rubbing it
against hair. To explain this we determined that electrons can move from one object to
another when rubbed together. This begs the question…
How do you know which object gains electrons and
which object loses electrons?
Every material has its own specific affinity for electrons. Through experiments, scientists have
created a list that ranks common materials in order of how strongly they attract electrons.
This list is called the Electrostatic Series
Tendency to
Relative
Material
GAIN electrons
Charge
Acetate
Glass
Wool
Fur, human hair
Nylon
Silk
Cotton
Polyethylene (plastic)
Carbon, copper, nickel
Ebonite
Rubber
Platinum, gold
When two objects are rubbed
together:
 the one closer to the top of
this series will _________
electrons and become
_________
 the one closer to the bottom
will ________ electrons and
become _________
If the following objects were rubbed together, what charge would they have?
Materials
Charge
Materials
Charge
(a) glass
(c) ebonite rod
cotton
(b) copper
nylon
wool
(d) human hair
plastic comb
Activity: Attract or Repel!
Instructions:
1. Complete all of your predictions using the electrostatic series BEFORE conducting the experiment.
1. Obtain a watch glass, two small pieces of plasticene or tape and an ebonite rod (with fur).
2. Charge the ebonite rod with fur, then attach it to the center of the watch glass using the plasticene or tape.
Charged object
Plasticene or tape
Watch glass
3. Charge a second ebonite rod with fur. Bring it near the charged rod on the watch glass without touching it.
4. Record the interaction between the objects in the data table blow.
5. Repeat step 3 using a glass rod charged with plastic then with acetate charged with cotton.
6. Repeat steps 1-5, first using a glass rod and then using acetate on the watch glass.
7. Repeat to determine the charge of vinly rubbed with cotton and a plastic comb rubbed with felt.
Predictions:
Using the Electrostatic Series, what were the charges for each charged object:
a) Ebonite Rod _______________
b) Glass Rod - ________________
c) Acetate - __________________
Fur - __________________
Plastic - ________________
Cotton - __________________
Based on your answers, place a + or – next to each object in your chart in the space provided.
Charged Object on Watch Glass
Charged Object in
Hand
Ebonite Rod (
Prediction
Ebonite Rod (
)
Glass Rod (
)
Acetate (
)
)
Observation
Glass Rod (
Prediction
)
Observation
Vinyl with cotton
Comb with felt
Charge of vinyl : _____________
Charge of comb : ______________