Experiment 1: Radioactive Decay of Pennies
Data Table 1: Radioactive Decay of Pennies
Half-lives passed Unstable pennies Stable pennies
0 200 0
1 105 95
2 51 149
3 28 172
4 13 187
5 7 193
6 4 196
7 3 197
8 1 199
9 0 200
10 0 200
Experiment 2: Radioactive Decay of Thumbtacks
Data Table 2: Radioactive Decay of Thumbtacks
Shakes Unstable thumbtacks Stable thumbtacks
0 50 0
1 38 12
2 28 22
3 23 30
4 19 37
5 16 42
6 14 46
7 10 49
8 8 49
9 6 50
10 4 50
Analyze
1. What happens to the number of unstable pennies as the number of half-lives increases?
2. Approximately what percentage of pennies were removed after each half-life? Why do you think this was the case?
3. What does the shaking of the pennies represent? Would the amount of time spent shaking the pennies affect your data?
4. What happens to the number of unstable thumbtacks as time passes?
5. Compare the shapes of the two graphs. What are the similarities? What are the differences? Describe the shape of each graph.
