CHAPTER 22 HOMEWORK 22-1 (pp. 701 702) Define. 1. nucleons 2. nuclide 3. mass defect 4. nuclear binding energy Solve. Use masses of 1.0087 amu for the neutron, 1.00728 amu for the proton, and 5.486 x 10 4 amu for the electron. 1. Calculate the binding energy per nucleon of a 55 25 Mn atom. The atom s atomic mass is 54.938 amu. 2. Calculate the nuclear binding energy for a mole of 16 8 O atoms. The atomic mass of 16 8 O is 15.995 amu. 3. Calculate the nuclear binding energy of a 32 16 S atom. The atomic mass is 31.972 amu. 4. What is the binding energy per mole for argon-40? The atomic mass is 39.962 amu. 1. Nuclear binding energy represents a. the energy required to break apart a nucleus. b. the measure of the stability of a nucleus. c. the energy required to bind the parts of the nucleus. d. both a and b 2. Which nuclear symbol matches an element that has 18 protons and 21 neutrons? a. 21 18Ar b. 39 18Ar c. 39 21Ar d. 39 18Al
CHAPTER 22 HOMEWORK 22-2 (pp. 702 704) Write true or false. 1. The band of stability represents the stable nuclei cluster over a range of electron-proton ratios. 2. The stability of a nucleus is greatest when the nucleons are in a 1:1 ratio. 3. 2, 20, 50, and 126 are all magic numbers. 4. A nuclear reaction is a change in the identity of a nucleus as a result of a change in the number of its protons. 5. In a transmutation, the number of protons changes, resulting in a change in the nucleus. Complete each equation. 1. 238 92U + 234 90 Th 2. 37 18Ar + 37 17 Cl 3. 244 94Pu + 4 2 He 4. 175 74W + 0 1 e 5. 246 96Cm + 12 6 C + 4 1 0 n 1. Which equation is correctly balanced? a. 210 83 Bi 0 1 e + 210 84 Po b. 210 83 Bi 0 1 e + 210 82 Pb c. 210 83 Bi + 0 1 e 210 84 Po d. 210 83 Bi 0 1 e + 210 82 Po 2. Which reaction is represented by this equation? 250 98 Cf + 10 5 B 258 103 Lr + 2 1 0 n a. Californium-98 reacts with boron-10 to produce lawrencium-258 and two nucleons. b. Californium-250 reacts with boron-10 to produce lawrencium-258 and two electrons. c. Californium-250 reacts with boron-5 to produce lawrencium-258 and two neutrons. d. Californium-250 reacts with boron-10 to produce lawrencium-258 and two neutrons.
CHAPTER 22 HOMEWORK 22-3 (pp. 705 707) Complete. 1. In the process of radioactive decay, a nucleus spontaneously disintegrates into 2. Radioactive decay is accompanied by 3. Nuclear radiation is. 4. A radioactive nuclide is GRAPHIC ORGANIZER Complete the chart by summarizing the different types of radioactive decay. List each type of decay and give a short explanation of what happens during each process. Type of Decay Explanation 1 The equation 238 92 U 4 2 He + 234 90 Th represents a. beta emission. b. alpha emission. c. gamma emission. d. electron capture. 2. The equation 22 11 Na + 0 1 e 22 10 Ne represents a. beta emission. b. alpha emission. c. gamma emission. d. electron capture.
CHAPTER 22 HOMEWORK 22-4 (pp. 708 712) Define. 1. half-life 2. decay series 3. parent nuclide 4. daughter nuclides 5. artificial transmutations 6. transuranium elements Solve. 1. The half-life of iodine-131 is 8.040 days. What percentage of an iodine-131 sample will remain after 40.2 days? 2. Uranium-238 decays through alpha decay with a half-life of 4.46 x 10 9 years. How long would it take for 7/8 of a sample of uranium-238 to decay? 3. What percentage of argon-39 has decayed after 1.50 x 10 3 years? (Its half-life is 265 years.) 4. A rock sample contained 5.0 g of In-115. The half-life of In-115 is 4.0 days. Determine the time when only 3.0 g of In-115 remains. 5. The half-life of a radioactive isotope is 6.0 hours. After 8 half-lives, how much of a 1.0-mg sample will remain? 1. Which process is occurring during the reaction represented by this equation? 120 50 Sn 4 2 He + 116 48 Cd a. beta decay b. gamma emission c. alpha decay d. the gaining of a positron 2. The half-life of H-3 is 12.26 years. What percentage of H-3 will remain after 0.100 centuries? a. 27.2% b. 0.568% c. 56.8% d. All of the element will have decayed.
CHAPTER 22 HOMEWORK 22-5 (pp. 713 716) Complete. 1. The unit used to measure nuclear radiation is the. This unit is equal to 2. One rem is defined as Complete the chart by writing the three methods that are used to detect radiation. Give a brief explanation or definition for each. Method Explanation 1. Someone says to you, All radiation is harmful. I don t know of any beneficial effects of radiation. What facts could you give to refute this person s statement? 1. Which statement is true? a. Alpha particles can only be shielded with glass or lead. b. Beta particles can be shielded with paper. c. Alpha particles can be shielded with paper. d. Beta particles are the most penetrating type of particle. 2. Which is not a common application of nuclear radiation? a. the estimation of the age of minerals and lunar rocks b. the development of liquid crystal polymers that prevent pollution c. the use of traces of chemicals that detect cancer d. prolonging the shelf life of food using rays from cobalt-60
CHAPTER 22 HOMEWORK 22-6 (pp. 717 719) Define. 1. nuclear fission 2. chain reaction 3. critical mass 4. shielding 5. nuclear fusion GRAPHIC ORGANIZER 1. What are the five main components of a nuclear power plant? 2. Draw a simple diagram that shows the parts of a nuclear power plant and how they are related. 1. Which statement is true? a. The most commonly used fissionable fuel is uranium-235. b. Fusion is the energy source of the sun. c. Nuclear reactors use controlled-fusion chain reactions. d. A chain reaction generally cannot proceed past three sets of reactions. 2. Nuclear fission is different from fusion in that a. fusion releases energy because nuclei are broken up. b. fission releases more energy per gram of fuel than fusion. c. fusion is more difficult to accomplish at low temperatures. d. fission involves the combining of small nuclei.