1. Chapter 28 Nuclear Chemistry Nuclear Radiation Nuclear Transformations Fission and Fusion Radiation in Your Life

2. Ch 28.1 Nuclear Radiation Radioactivity Types of Radiation

3. Radioactivity Radioisotopes – an isotope that has an unstable atomic nucleus and undergoes radioactive decay Always accompanied by large emissions of energy Not affected by temp., pressure, or catalysts Can not speed up or slow down the reaction or turn off

4. Radioactivity Marie Curie – (1867-1934) named the process Process by which unstable atomic nuclei achieve stability Won Nobel Peace Prize – 1903 along with Pierre Curie and Antoine Henri Becquerel

5. Radiation Penetrating rays and particles emitted by a radioactive source

6. Types of Radiation Alpha Beta Gamma

7. Alpha Helium nuclei emitted from a radioactive source Alpha particles Contain 2 protons and 2 neutrons and have a double positive charge 4 2 He or  Can be stopped by a sheet of paper or your skin

8. Beta Fast moving electrons formed by the decomposition of a neutron Beta Particles 0 -1 e or  Can be stopped by aluminum foil or pieces of wood

9. Gamma High energy electromagnetic radiation  No mass, no charge Can almost be stopped by several feet of concrete or several inches of lead

10. Chernobyl April 26, 1986 at 1:23:44am Reactor 4 exploded Released 30-40 times the amount of radiation as bombing Japan did

18. Chapter 28.2 Nuclear Transformations Nuclear Stability and Decay Half – Life Transmutation Reactions

19. Nuclear Stability and Decay 1500 different nuclei, only 264 are stable For low atomic number (up to 20), the ratio of protons to neutrons is 1(ratio of stability) 12 6 C 14 7 N Atomic numbers above 20, have a ratio of protons to neutrons of 1.5(ratio of stability) 206 82 Pb

21. Beta Emissions 66 29 Cu  66 30 Zn + 0 -1 e 14 6 C  14 7 N + 0 -1 e

22. Positron Particle with the mass of an electron, but a positive charge 0 +1 e 8 5 B  8 4 Be + 0 +1 e

23. Alpha Emission All nuclei with an atomic number greater than 83 are radioactive 204 82 Pb  200 80 Hg + 4 2 He 226 88 Ra  222 86 Rn + 4 2 He

24. Half Life The time required for one half of the nuclei of a radioisotope sample to decay to products

27. Artificial Radioisotopes Usually have very short half lives Used in nuclear medicine

28. PET Scan - Positron Emission Tomography

31. Brain Function

32. Thyroid Tumors Dog Iodine 131

33. Bone Fractures Technetium

34. Radioactive Isotope Use C-14 Used to determine the age of biological remains (archaeology) I-131 Used to detect and cure hyperthyroidism (overactive thyroid) Co-60 Used as a source of radiation for radiotherapy of cancer Tc-99m Used to image blood vessels, especially in the brain, to detect tumors Pu-239 Used as a highly fissionable fuel source for nuclear power or nuclear weapons Am-241 Used in tiny amounts in smoke detectors as a source of ions to make a current U-235 Used as fissionable fuel source for nuclear power or nuclear weapons U-238 Used to determine the age of uranium-containing rock formations (geology)