Assigned
Name: ________________________________# _____ Team: IRROYGBPUV Period: ____
Due
Physical Science 1: Chemistry
Nuclear Chemistry: Modeling a Chain Reaction
Background:
In a nuclear fission chain reaction, a nucleus is struck by a neutron, which causes the nucleus to split into two
smaller nuclei and to release other neutrons. If these neutrons strike other nuclei, a chain reaction can occur. In this
lab, you will model a nuclear fission chain reaction using dominoes.
Problem: How can you manufacture a model of a nuclear fission chain reaction?
Materials: 20 Dominoes, A student provided timing device and a metric ruler.
Procedure:
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1.
A. Stand 15 dominoes in a single straight row in such a way that the distance between them is about
One-half of their height.
B. Knock over the first domino.
Measure and record the time it takes for all of the dominoes to fall over.
2. Repeat Step 1 two more times. Remember to measure and record the time it takes for all of the
dominoes to fall over.
3. Arrange 15 dominoes as show in Figure 2, so that each domino will knock over two others.
Observe what happens when you knock over the first domino.
Measure and record the time it takes for all of the dominoes to fall over.
4. Repeat Step 3 two more times.
Calculate the average for the three time measurements to get a more accurate number.
5. Set up 15 dominoes again as you did in Step 3.
This time, however hold a metric ruler on end, in the middle of the arrangement of dominoes.
See Figure #3.
Knock over the first domino. Observe and record what happens.
6. Set up 15 dominoes again as you did in Step 3, but this time, place 5 additional dominoes at right
angles to 5 randomly chosen dominoes to provide support as shown in Figure 4. These five supported
dominoes represent atoms of a different isotope that must be struck with more energy to undergo
nuclear fission.
7. Knock over the first domino. Measure and record the time it takes for the dominoes to fall and how
many dominoes fall.
8. Repeat Steps 6 and 7 two more times. Then average the three measures to get a more accurate time.
9. Repeat Steps 6 through 8, but this time place supporting dominoes behind only 3 randomly chosen
dominoes.
10. Repeat Steps 6 through 8, but this time place supporting dominoes behind only 1 randomly chosen
domino.
Right on
time
Assigned
Name: ________________________________# _____ Team: IRROYGBPUV Period: ____
Due
Physical Science 1: Chemistry
Nuclear Chemistry: Modeling a Chain Reaction
Data and Calculations: Time in seconds.
Step #
1-2
Trial 1
Trial 2
Trial 3
Average Time
Step #
1-2
3-4
3-4
6-8
6-8
9
9
10
10
Step #
Trial 1
Analyze and Conclude
Trial 2
Trial 3
Average Time
Step #
1
Calculating: What was the average fall time for the arrangement of dominoes in Steps 1 & 2? In Steps 3 & 4?
Steps 1 & 2 =
Steps 3 & 4 =
2
Applying Concepts: What type of reaction was modeled in Steps 3 & 4?
3
Using Models: In your falling-dominoes model of nuclear fission chain reactions, what did a standing domino
represent? What did the fall of a domino represent?
Standing domino =
Fall of a domino =
4
Using Models: In your falling-dominoes model of nuclear fission chain reactions, what did the striking of one
domino by another represent? What did the metric ruler represent?
Domino Strike =
Metric Ruler =
5
Analyzing Data: Before a sample of an easily fissionable isotope is used, it is refined by removing less
fissionable isotopes of the same element. On the basis of your observations in Steps 6 through 10, explain why
this refinement is necessary.
6
Inferring: What factors do you think would affect the rate of a nuclear fission chain reaction?
7
Drawing Conclusions:
are not present?
8
Evaluating and Revising: What are some of the limitations of using falling dominoes to model a nuclear
fission chain reaction? Suggest how you might revise this model to make it more representative of a chain
reaction.
Limitations:
Revisions:
What do you think would happen to a nuclear fission chain reaction if control rods
Go Further: Find out about the Manhattan Project and how it made history. Using what you have learned
from the falling dominoes model to help you understand the scientific discoveries related to controlled and
uncontrolled nuclear chain reactions.
Controlled Chain Reaction
Uncontrolled Chain Reaction
Left is
late
Right on
time
Assigned
Name: ________________________________# _____ Team: IRROYGBPUV Period: ____
Due
Physical Science 1: Chemistry
Nuclear Chemistry: Modeling a Chain Reaction
#
Minnesota and Geologic Time Reading
(Questions are in ranked order of importance)
Student Created Question:
Answer
1
2
3
4
5
6
7
8
9
10
#
Student Created Question:
Why is question number one the most important one on
your list?
Left is
late
Answer
Right on
time
Assigned
Name: ________________________________# _____ Team: IRROYGBPUV Period: ____
Due
Physical Science 1: Chemistry
Nuclear Chemistry: Modeling a Chain Reaction
Physical Science Graphing Assignment: ______________________________________
Graph Title: _________________________________________________
X
Axis
Time
(s)
0
Y
Axis
# of
ato
ms
0
15
30
45
60
75
90
105
120
135
150
15 is the average for
all trials. Multiply to
find the rest of the X
.values
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A
Title
B
Key
C
Key
Labeled
D
Color
Ten Element Checklist Key.
E
F
G
Appropriate
X & YCorrect
Intervals
axis
Units
Labeled on axis
H
Scales are
appropriate
I
Scale is
uniform
J
Origin is
identified
Right on
time