The following data represents the activity of a radioactive isotope 223 87 Fr.
| time/min | 0 | 5 | 10 | 15 | 20 | 25 | 30 | 35 | 40 |
| activity in counts/min | 680 | 575 | 495 | 425 | 355 | 300 | 265 | 230 | 210 |
1. Use the data to plot a graph.
2. From the graph determine the time for the count to drop
(a) to half the first value
(b) from three-quarters to three-eighths of the first value
(c) from two-thirds to one-third of the first value.
3 Determine the half life of the isotope.
4. What is the order of this decay process? Explain.
5. Calculate the rate constant for the radioactive decay.