Sonoma State University
Fall 2002

Physics 481
John Dunning, Jr.

Problem Suggestions #1

Problem sets are due each Wednesday. Only those problems covering material actually discussed in class by Monday are due. Because of Labor Day this first problem set is due Wednesday September 11.

Use the Chart of the Nuclides for problems 1-5.

  1. 32P is used in many biological research projects because it can be used to tag DNA fragments. What is detected?
  2. 131I is used to test the uptake of the thyroid. What types of radiation and energy are emitted? What is actually detected outside the patient?
  3. Compare the Chart of the Nuclides listing for 60Co with the decay scheme on p. 22 of our text. Are the two gamma rays always emitted in coincidence (one rapidly following the other from the same decay), or does one decay emit one gamma and another decay emit the second gamma?
  4. 57Co decays by electron capture. What is the product isotope? What nuclear gamma rays are to be expected? Some of these will be used to calibrate our germanium detector. In addition there are K X-rays from the product atom. These are listed in red on the periodic table of the elements in the back of the Chart of the Nuclides. What are the energies of these two X-rays?
  5. Write down all the decay modes of 40K in order of decreasing probability. List the final stable nuclei. Which decay mode is used for potassium-argon dating? Remember the gamma ray listed arises from a de-excitation of the product nucleus and is not a separate decay mode.
  6. Problem 2-29.
  7. Problem 2-30.

  8. Problem 2-37. Assume only the 235U is radioactive for a start. The exact solution will be worked in class. The a/o (= atom percent) at present is given on the Chart of the Nuclides.

    Problem 2-38 (use equation 2.30).

    Problem 2.39 part a only. What is this time for the 99Mo - 99Tc-m- 99Tc decay chain. 99Tc may be assumed stable for this problem. (This assumes we get to parent-daughter equilibrium in class)..

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