1. TOPIC: Benefits & Dangers of: Radioisotopes Do Now: Draw Bohrs Model for the Cl-35 isotope

2. RADIOISOTOPE - isotopes who’s nucleus is unstable and dissipate excess energy by spontaneously emitting radioactive particles (we will learn about these next week)

3. Carbon-14 Carbon Dating Not that kind of dating?!

4. C-14 used to date organic (previously living) materials

5. U-238 decay series U-238 decays to Pb-206 (many steps) Over time, amount of U  and amount of Pb  –Scientists use the ratio of U-238 to Pb-206 to date rocks

6. Radioactive Tracers Determine the way in which a chemical reaction occur –P-31: determines P uptake in plants –C-14: maps C in metabolic processes –C-14: maps organic molecules and figures out reaction mechanisms Used to track the distribution of a substance in cells/tissues in the body

7. Medical radioisotopes with short half-lives (quickly eliminated from the body) –Tracers in medical diagnosis –Treatment of cancer I-131: Diagnosis & treat thyroid disorders Co-60: gamma emitter –Used to kill cancerous tumors Tc-99: treatment of brain cancer

8. Industrial Applications Kill bacteria and spores in food and mail Co-60: kills bacteria in foods l

9. Power Plants Used as a fuel source to generate electricity No contributions to greenhouse gases

10. Radiation Risks Can damage normal tissue High doses can cause illness & death Can cause mutations in DNA Disposal of waste is difficult (esp. from nuclear power plants) Have long half-lives and remain radioactive for long periods of time

11. Chernobyl