To accurately describe the isotopes based on the information provided, we need to analyze the information in relation to their half-lives. The amount of radioactivity from isotopes typically decreases over time, and the rate of decrease (or the half-life) will determine how long it takes for a given isotope to become significantly less radioactive.
Based on the measurements given:
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Isotope A:
- Measured at multiple times: Day 24, Day 18, Day 24, and Day 30.
- The radioactivity readings should show a decreasing trend, which would suggest a longer half-life if the isotope retains some activity even at later days.
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Isotope B:
- Measured at Day 6, Day 4, Day 8, and Day 6.
- If these earlier days show higher radioactivity, it suggests B has a shorter half-life than A.
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Isotope C:
- Measured at Day 10, Day 5, Day 20, and Day 10.
- Similar to the previous isotopes, we look at the time points to determine the half-life.
Now to categorize:
- Isotope A likely has the longest half-life (thus measurable at the latest point, Day 30, while still showing some measurable radioactivity).
- Isotope B probably has a shorter half-life since it shows activity at the earlier measurement points (Day 4, Day 6).
- Isotope C's measurements are mixed, but there's a range in its measurements that could indicate a medium half-life depending on which readings are decreasing more significantly.
In conclusion:
- Isotope A: Longest half-life, stable activity over weeks.
- Isotope B: Shortest half-life, rapidly decreasing activity.
- Isotope C: Intermediate half-life, variable measurements over the days indicating a moderate decay rate.
Without specific numbers from the chart that presents the radioactivity, we can only conclude based on the patterns of measured times. Further analysis of the actual decay curve would provide more precise details.