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Separating Two Decay Signals in a Simulation 4 questions
Separating Two Decay Signals in a Simulation
Base your answers on the information provided and your knowledge of chemistry. Use the 2025 Chemistry Reference Tables as needed.
A class simulates a sample containing two independent radioactive species. Its detector reports separate signals for P and Q. Each signal is proportional to the number of parent nuclei remaining. Ignore background counts.
| Species | Initial signal (units) | Half-life (h) |
|---|---|---|
| P | 80 | 2 |
| Q | 40 | 4 |
Question 1
Calculate the signal from each species after four hours. Show how the number of half-lives differs.
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Question 2
Which statement compares the fractions of the initial signals lost by four hours?
- P loses a greater fraction than Q.
- Q loses a greater fraction than P.
- Both species lose the same fraction.
- Both species lose all of their signals.
The class replaces the detector with one that reports only the sum of the two signals. A student assigns the mixed sample a single half-life of four hours.
Question 3
Use the summed readings at zero and four hours to test that claim.
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Question 4
At eight hours, which species supplies more of the summed signal? Support your conclusion with its signal and the other species’ signal.
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