1. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. PHYSICAL SCIENCE sixth edition Bill W. Tillery Chapter 13 Nuclear Reactions

2. Homework Assignment Chap 13 Read p 353 - 361 Applying the Concepts (p 380): 1 – 9, 13, 31, 32, 35, 36, 37, 38, 45

3. Nuclear reactor with top and control rods removed

4. Nuclear energy usage for electricity, 2004

5. Fig. 13.2 Discovery of radioactivity by Becquerel (1896) Chemical reactions involve the outer electrons in atoms Nuclear reactions involve the inner nucleus of an atom

7. ParticleCompositionChargePenetration Alphaα 2 protons and 2 neutrons 2+ stopped by paper Betaβ an electron 1- stopped by aluminum Gammaγ pure energy 0 stopped by lead Radioactive particles

8. Relative penetrating abilities of alpha, beta, and gamma radiation

9. nucleus Proton and neutron called “nucleons”

10. Atomic number (Z) = number of protons in nucleus Mass number (A) = number of protons + number of neutrons = atomic number (Z) + number of neutrons Isotopes - atoms of the same element (X) with different numbers of neutrons in their nuclei X A Z U 235 92 U 238 92 Mass Number Atomic Number Element Symbol

11. Fig. 13.4 The three isotopes of hydrogen H 1 1 H (D) 2 1 H (T) 3 1

12. Fig. 13.5 Plot of neutrons versus protons Band of Stability

14. Fig. 13.6 Types of radioactive emission depends on neutron-to-proton ratio Unstable nuclei undergo radioactive decay to form more stable nuclei Nothing can change the rate of radioactive decay

15. Fig. 13.7 Radioactive decay series for uranium-238 (One of three naturally occurring series)

16. Fig. 13.8 Radioactive decay of a hypothetical isotope with a half-life of 1 day

18. Origins of Radiation Exposure in the US Natural background (81%): Biggest source: Radon-222 Medicine (15%) Consumer products (4%) Can’t see it Can’t smell it Can’t taste it Can’t hear it Can’t feel it

19. Zone 1 (red zones)Highest Potential Zone 2 (orange zones)Moderate Potential Zone 3 (yellow zones)Low Potential

20. Biological Effects of Radiation Radiation absorbed dose (rad) Roentgen equivalent for man (rem) Units of Radiation Chemically inert, uncharged noble gas Produced from decay of uranium-238 Seeps out of rocks and soil Builds up indoors and in mines T 1/2 is 3.8 days Decays by alpha particle emission Produces short-lived solid alpha-emitters - Polonium 218 and 214 Radon-222

21. Fig. 13.11 Working parts of a Geiger counter

22. Table 10.1