2. Medicine imaging and tumor treatments Thyroid imaging using Tc-99 Uses of Nuclear Radiation

4. Food Irradiation Food can be irradiated with gamma rays from 60 Co or 137 Cs. Irradiated milk has a shelf life of 3 months without refrigeration. USDA has approved irradiation of meats and eggs.

5. 1000-10,000 kilorads

6. Isotope Half-Life Radiation Emitted Carbon-14 5,730 years  Radon-222 3.8 days  Uranium-235 7.0 x 108 years  Uranium-238 4.46 x 109 years  Radiocarbon Dating--The radioactivity of a sample can be used to determine how old it is. Half-life: The time for half of the nuclei to decay.

7. Half-Life Graph

8. The times given in this table are the “half-life” values for the decay of U-238 into Pb-206.

9. Transuranium Elements: Beyond #92