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Recovering Decays From Two Nuclear Totals 4 questions
Recovering Decays From Two Nuclear Totals
Base your answers on the information provided and your knowledge of chemistry. Use the 2025 Chemistry Reference Tables as needed.
A simulation keeps a record of the parent nuclei and their resulting heavy nuclei. It excludes the emitted particles from the record. Each alpha decay lowers the recorded mass-number sum by four and the atomic-number sum by two. Each beta-minus decay leaves the mass-number sum unchanged and increases the atomic-number sum by one. Only these two decay types occur.
| Sum over the recorded nuclei | Before | After |
|---|---|---|
| Mass numbers | 400 | 388 |
| Atomic numbers | 160 | 156 |
Question 1
How many alpha decays are needed to explain the mass-number change?
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- 2
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Question 2
Use the atomic-number sum to calculate the number of beta-minus decays.
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Question 3
A student says the atomic-number change by itself determines how many alpha decays occurred. Give a different event combination that would cause the same atomic-number change.
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In a later window the mass-number sum does not change. The atomic-number sum increases by three.
Question 4
Identify how many of each decay type occurred in the later window. Explain how the two records constrain the result.
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