1. 1 The following isotopes decay by positron emission. 11 C 18 F 82 Sr What are the daughter isotopes?

2. 2 In positron emission tomography (PET scan), a molecule containing a positron emitting isotope is injected into the patient to follow the flow of blood. However, positrons, being a type of beta radiation, do not travel far through the tissue. How can they be detected so that imaging can be done?

3. 3 The 3 most common isotopes of radon are 222 Rn, 219 Rn, and 220 Rn. a. Using the decay chains for Uranium and Thorium: Starting with the parent isotopes, indicate what type of radiation is released at each step leading to radon. b. With what stable element do all the uranium/thorium chains end? c. Given the source of radon gas (where it physically comes from), why would the half life of the particular radon isotope influence how much of a health hazard it is?

4. 4 The following shows the production and decay of the isotope Tc-99: a.Indicate what type of radiation is released at the steps indicated with “?” b.What type of radioactive decay reaction is represented by the 2 nd “?”

5. 5 Use http://www.mcgill.ca/ehs/radiation/basics/radioisotopes/ to answer the following questions. http://www.mcgill.ca/ehs/radiation/basics/radioisotopes/ a.Every month you must account for how much radioactivity you have on hand. September 1 you had 1.7 mCi of S-35. How much will you have on October 1? b.Which one of the following has the shortest half life? a.P-32C-14 S-35 or H-3? c.What percentage of the original activity is left in a sample that has decayed 8 half-lives?

6. 6 You purchased 1 mCi of P-32 for your experiments. On September 22, your package arrives. According to the information sheet, the package contained 1.2 mCi on September 20. You know that you will not be able to perform an experiment until September 25. The vial contains P-32 in a total volume of 500  l. You will need 200  Ci to do your experiment. What volume of radioisotope solution will you need? more problems