Question

4. The decay of the radioisotope 1-131 was studied in a laboratory. The data collected are plotted on the graph below. Disintegration Rate (decays per minute) 16,000 14.000 12.000 10,000 8.000 2.000 20 24 8 12 16 Time (days) a. Determine the half-life, t12, of l-131 using the graph above. b. The data can be used to show that the decay of l-131 is a first-order reaction, as indicated on the graph below. 8 12 16 20 24 Time (days) (i) Label the vertical axis of the graph above. (ii) What are the units of the rate constant, k, for the decay reaction? (iii) Explain how the half-life of I-131 can be calculated using the slope of the line plotted on the graph. C. Compare the value of the half-life of 1-131 at 25°C to its value at 50°C.

Answer 1

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8
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