Name ___________________________________
Unit 6 Sticky Tape Post-Lab
Thomson Model and Sticky Tape
1. Draw a particle diagram of Thomson's model of the atom:
2. What 3 conclusions can you make by the observations you made from the Sticky Tape lab?
REMEMBER these!
3. In the Sticky Tape lab, which tape (top or bottom) did we determine to be negative after being ripped apart from the
other tape? How did you conclude this? If this is true, how did this tape become that charge?
4. Fill in the table below and be ready to discuss:
Insulators (nonmetals)
Conductor(metals)
How do electrons move (shift within the
atoms or jump from atom to atom)?
This is polarization.
Do electrons have a strong attraction or
weak attraction to their atom's +
"pudding"?
(within the atom)
Draw a particle diagram showing what
happens to the electrons when a (-)
charge is brought near to this object
After polarization, is there a weak or
strong attraction between the particles
5. What is it called when the electrons move from atom to atom or within the atom and produce
temporary (+) and (-) ends of the atom?
6. How do atoms become a negative (-) charge? (is there a gain or loss of electrons (e-) ). Fill
diagram on the right to illustrate your point.
0 (indicates the charge)
Before (neutral atom)
After (negative)
in the particle
Circle which is
correct:
Gain or Loss
7. How do they become a (+) charge? (is there a gain or loss of (e-)). Fill in the particle diagram on the right
illustrate your point.
Before (neutral atom)
0
After (positive)
Circle which is
correct:
Gain or Loss
Modeling Chemistry
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U6 Sticky Tape v1.0
Sticky Tape Lab Particle Diagram & Descriptions:
Let’s see how we can use Thomson’s model to explain the behavior of the sticky tape when we made our
tape stacks.
A few atoms from the top tape and the bottom tape are represented in the diagram below.
Describe the macroscopic changes (what you observed with your eyes) in the tapes and then provide a
microscopic (what happened to the “plums” or electrons) explanation based on Thomson’s model of the
atom and your drawings.
Macroscopic( what you saw with your eyes):
Microscopic (describe what you see what’s happening inside the atoms of each tape as
illustrated above):
Behavior of Foil and Paper with Charged Tapes
We observed that neither foil (metal atoms) nor paper (non-metal atoms) would attract
each other. But foil and paper are both attracted to both the charged tapes (top and
bottom).
How can we use the pudding model of atoms to explain the differences we
observed?
Several atoms from the paper and foil are drawn below. The ones on the left have no charged
object near them. The ones on the right are next to a top tape
(+ charge).
Add force vectors (arrows showing the direction of the movement of atoms) to the
non-metal (paper) atoms and the top tape in the first row to show the attraction between the
paper and the tape. Then do the same for the foil and the tape in the second row. Be sure the
size of the vectors shows the relative strengths of the attractions (the more the attraction, the
bigger the arrow).
Now draw the electrons in each atom “bowl” to show their arrangements when no charged
object is near present and then when a charged object is brought near.
Non-metal (paper)
no charged object near
Modeling Chemistry
Non-metal (paper)
top tape near
2
Top Tape
U6 Sticky Tape v1.0
no charged object near
Metal (Al foil)
top tape near
Top Tape
Explain why these arrangements of electrons would produce the observed attractions.
In other words, why were the metal atoms more attracted to the charged
objects than the nonmetal objects.
Summary of charges:
1. The top tape became a __________ charge.
a. I was able to determine its charge because _____________________________________.
b. It became this charge because it ________________ some of its negative charges to
the bottom tape.
2. The bottom tape became a __________ charge.
a. I was able to determine its charge because _____________________________________.
b. It became this charge because it __________ some negative charges from the top
tape.
3. The foil and the paper were considered a __________ charge.
a. I was able to determine this fact because ______________________________________.
b. A neutral charge means that the ________ and ________ charges are _________
inside each atom.
c. The FOIL (CONDUCTOR) had a _____________ attraction to charges because its
electrons can ____________ from atom to atom.
d. The PAPER (INSULATOR) had a __________ attraction to charges because its
electrons only ___________ within the atoms and DO NOT “jump” from atom to
atom.
4. Re-write the 3 conclusions for the Sticky Tape lab:
5. In your own words, DEFINE POLARIZATION:
Modeling Chemistry
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U6 Sticky Tape v1.0