Name Date Nuclear Chemistry Review Packet 1. The ratio of stability is (1) proton : neutron (2) neutron : proton (3) proton : positron (4) beta : proton 2. Which nuclear reaction is classified as alpha decay? 3. Which radioactive particles have a charge of 2+? (1) alpha particles (2) beta particles (3) gamma rays (4) neutrons 4. Given the reaction,, the nucleus represented by X is 5. Given the reaction,, which particle is represented by X? (1) alpha (2) beta (3) neutron (4) protons 6. A positron has (1) a negative charge and a mass of 0 (2) a positive charge and a mass of 1 (3) a positive charge and a mass of 0 (4) no charge and a mass of 1 7. Gamma rays have (1) mass but no charge (2) charge but no mass (3) neither mass nor charge (4) both mass and charge 8. In an electric field, what will be deflected toward the negative electrode? (1) beta particle (2) alpha particle (3) x rays (4) gamma rays 9. Which equation represents the radioactive decay of? 10. Which radioactive sample would contain the greatest remaining mass of the radioactive isotope after 10 years? (1) 2 g of 198 Au (2) 2 g of 42 K (3) 4 g of 32 P (4) 4 g of 60 Co 11. In how many days will a 12g sample of I-131 decay to 1.5 grams? (1) 8 (2) 16 (3) 20 (4) 24
12. Bombarding a nucleus with particles that changes one element into another is called (1) a half-reaction (2) a breeder reaction (3) artificial transmutation (4) natural transmutation 13. Given the reaction, X represents 14. The nuclear reaction is an example of (1) natural radioactivity (2) nuclear fission (3) natural transmutation (4) artificial transmutation 15. Which equation represents a fusion reaction? 16. Compared to a nuclear reaction, a chemical reaction differs in that the energy produced by a nuclear reaction is (1) greater (2) smaller (3) the same 17. Which conditions are required to form during the fusion reaction in the sun? (1) high temperature and low pressure (2) low temperature and low pressure (3) high temperature and high pressure (4) low temperature and high pressure 18. In a fusion reaction, a major problem related to causing the nuclei to fuse is the (1) small mass of nuclei (2) large mass of nuclei (3) attractions of nuclei (4) repulsions of nuclei 19. Which radioactive isotope is often used as a tracer to study organic reaction mechanisms? (1) carbon-12 (2) carbon-14 (3) uranium-235 (4) uranium-238 20. Radioisotopes used in medical diagnosis should have (1) short half-lives and be quickly eliminated from the body (2) short half-lives and be slowly eliminated from the body (3) long half-lives and be quickly eliminated from the body (4) long half-lives and be slowly eliminated from the body
Part 2 Questions 1. Write the decay equations for the following: a) alpha decay of Am-241 b) beta decay of Co-60 2. 3 H has a half-life of 12.31 years. How much of a 60 g sample will remain after 36.93 years? 3. 100 grams of a radioisotope decayed to 6.25 grams after 21 years. What is the half-life? 4. A radioisotope has a half-life of 8.5 minutes. After 25.5 minutes, 10 grams remain. What was the initial amount? 5. What is the difference between natural and artificial transmutation. Looking at a nuclear equation, how can you tell the difference? 6. Compare and contrast fission and fusion reactions. 7. List the benefits and risks of radioisotopes.
Answer Key 1. 2 6. 3 11. 4 16. 1 2. 3 7. 3 12. 3 17. 3 3. 1 8. 2 13. 2 18. 4 4. 1 9. 4 14. 4 19. 2 5. 2 10. 4 15. 3 20. 1 Part 2 1. a) b) 2. 0 60 g 0 1 30 g 12.31 y 2 15 g 24.62 y 3 7.5 g 36.93 y 7.5 grams 3. 0 100 g 0 1 50 g 5.25 y 2 25 g 3 12.5 g 4 6.25 g 21 y 21 y / 4 = 5.25 y 4. 0 80 g 0 1 40 g 8.5 min 2 20 g 17 min 3 10 g 25.5 min 80 grams
5. Natural transmutation is the spontaneous decay of one element into another. All radioisotopes on Table N undergo natural transmutation. An equation will show natural transmutation when there is only one particle on the left side of the arrow. Artificial transmutation is the bombarding of an atom with another particle to force a decay to occur. An equation will show artificial transmutation when there are two particles on the left side of the arrow. 6. In a fission reaction, a heavy atom splits into lighter pieces. The reaction usually involves uranium, and neutrons will be written on both sides of the arrow. The neutrons that are produced split other nuclei in a chain reaction. If the reaction is controlled, it can be used to produce energy in power plants. If it is uncontrolled, it can be used as an atomic bomb. Fission produces a lot of radioactive waste. In a fusion reaction, light nuclei combine to form a heavier nucleus. The reaction involves any combination of hydrogen and/or helium, both written on the left side of the arrow. This is the reaction that occurs on the sun to produce solar energy. If uncontrolled, it is used in the hydrogen bomb. Fusion reactions are difficult to accomplish because both nuclei that are combining are positive; therefore high pressures and high temperatures are needed. Fusion produces more energy than fission and does not produce waste. Both fission and fusion are classified as nuclear reactions, so they convert mass into energy. Both reactions produce much more energy than chemical reactions. 7. Benefits: A) Tracers: C-14 B) Medical: Tc-99 (tumors), I-131 (thyroid disorders), Co-60 (cancer) C) Food Storage D) Radioactive Dating: U-238 (geological), C-14 (once living materials) E) Nuclear Power Risks: A) Biological Damage B) Long-term Storage/Disposal C) Accidents/Pollution