1. Applications of Radioactivity

2. Geological Dating
Certain isotopes are used for dating a variety of materials, including rocks and human remains.
238U is especially useful for rocks, with a half life of 4.5 billion years.
14C is used for measuring material less than 50,000 years old.

3. Radiotracers
Tracers – complex chemical reactions can be followed using certain radioisotopes.
Tracers are particularly useful in biochemistry and medicine, especially in toxicology.
131I is useful for studying thyroid conditions, 99Tc is used for bone disorders.
These substances have very short half-lives.

4. Cancer Treatment
Cancer cells are somewhat more vulnerable to radiation than normal cells
Radiation can be applied to a tumor directly, or a small sample of a radionuclide can be surgically implanted in the tumor.
60% of cancer patients receive radiation treatment

5. PET Scans (Positron Emission Tomography)
River Radiology has a particle accelerator
Makes its own 18F, a positron emitter
“Hot” fluorine is bonded to sugar and ingested
Cancer cells devour sugar – hot areas indicate where cancer is.

6. 18F Decay Curve What is the half-life of fluorine-18?
Write the decay equation!

7. Food Preservation Cobalt-60 has been used to kill bacteria in food
In the former Soviet Union, this practice was widespread
500,000 tons of food items are irradiated per year worldwide in over 40 countries.
These are mainly spices and condiments with an increasing segment of fresh fruit irradiated for fruit fly quarantine
Irradiated food is not radioactive.
Practice is controversial in many countries…