1. NUCLEAR CHEMISTRY SUROVIEC SPRING 2015 Chapter 19

2. I. Types of Radiation Radioactivity was discovered in 1896 by Bequerel and further work was done by Curie and Rutherford.

3. A. Isotope review X A Z Mass Number Atomic Number Element Symbol

4. B. Alpha decay Alpha decay occurs when an unstable nucleus emits a particle composed of 2 protons and 2 neutrons.

5. C. Beta decay Beta decay occurs when an unstable nucleus emits an electron

6. D. Gamma rays Gamma ray emission is a high energy/short wavelength electromagnetic radiation.

7. E. Positron emission Positron emission occurs when an unstable nucleus emits a positron

8. F. Electron capture Electron capture involves a particle being absorbed by instead of ejected from an unstable nucleus

9. II. Kinetics of radioactivity Radioactivity is the spontaneous emission by unstable nuclei of particle or electromagnetic radiation to get to a stable configuration. All radioactive decay is first order kinetics

10. Example A tree sample has an activity of 10.1 atoms/min of carbon. If a living tree has a decay rate of 15.3 atoms/min, how old is the tree sample?

11. Example Americium-241 is used in smoke detectors. Its half life is 432 years. How long will it take for 33% of the Am-241 to decay (in years)?

12. III. Fission Enrico Fermi tried to synthesize a new element by bombarding uranium with neutrons

13. A. Nuclear power Fission can be used to make a bomb, but in that case all of the energy is released at once.

14. IV. Nuclear Fusion Fusion is the combination of 2 nuclei to form a heavier nuclei.

15. IV. Radiation in everyday life Radiation absorbed dose (rad) 1 rad = 1 x 10 -5 J/g of material Roentgen equivalent for man (rem) 1 rem = 1 rad x RBE Relative Biological Effectiveness  -ray = 1  = 1  = 20

16. 19_T04.JPG

17. A. Uses in Medicine It is immensely useful to use radioactivity in medical diagnosis