Radioactivity Test Review Multiple Choice Identify the letter of the choice that best completes the statement or answers the question. 1. Radioactive s have unstable a. electrons. c. protons. b. nuclei. d. neutrons. 2. Alpha particles a. are positively charged. b. consist of two protons and four neutrons. c. can penetrate any thickness of matter. d. All of the above 3. The type of nuclear radiation that can penetrate farthest through matter is called a. radons. c. alpha particles b. gamma rays. d. beta particles 4. The process of nuclear change in an atom of radioactive is called a. nuclear decay. c. nuclear mass. b. isotopes. d. radon. 5. Nuclear radiation refers to charged particles or energy emitted by an unstable a. proton. c. nucleus. b. atom. d. isotope. 6. In alpha decay, the mass number of the atom before the decay a. equals the sum of the mass numbers of the products. b. does not change after the decay. c. is the same as the atomic number. d. cannot be determined. 7. As beta particles ionize they a. lose energy. c. neither lose nor gain energy. b. gain energy. d. None of the above 8. During beta decay, a nucleus a. gives up two protons and two neutrons. b. maintains the same number of protons and neutrons. c. loses a proton and gains a neutron. d. gains a proton and loses a neutron.
9. When a nucleus undergoes nuclear decay by gamma rays, the atomic number of the element a. remains the same. c. decreases by one. b. increases by one. d. increases by two. 10. In radioactive decay, with each successive half-life, half the remaining sample decays to form another a. nucleus. c. life-form. b. element. d. proton. 11. Nuclear fission is the: a. Production of uranium. b. Splitting of protons by bombarding them with neutrons. c. Splitting of atoms by bombarding them with neutrons. d. Result of neutrons smashing into each other. 12. During fission: a. Electrons are released and cause more fission. b. Protons are released and cause more fission. c. Uranium is produced. d. Neutrons are released and cause more fission. 13. The weapons grade fuel needed for the first atomic bomb was: a. Hydrogen b. Uranium-235 c. Uranium-238 d. Uranium-571 14. Separating U-235 from U-238 was a problem because: a. There was so much more U-235 than U-238 b. There was so much more U-238 than U-235. c. A chain reaction would result. d. They are chemically identical. Questions 15-22 (*= More than one answer MAY be needed.) a) alpha b) beta c) gamma d) omega 15. Made up of an electron B 16. An energy wave C 17. Made up of two protons and two neutrons A *18. Does not change mass number B, C 19. Reduces mass number by 4 A *20. Does not change atomic number C 21. Reduces atomic number by 2 A 22. Increases atomic number by 1 B
23. Which of the following is the correct isotope formula? a) b) c) d) e) ab) --------------------------------------------------------------------------------------------------------- 24. What is the atomic number of the element shown above? 25. What is the mass number of the element shown above? 26. How many protons does the element have in its nucleus? 27. How many neutrons does the element have in its nucleus? The above is a model for radioactive decay. The entire rectangle represents 100% of the radioactive with each individual block representing one atom. The portion that is NOT shaded represents atoms that have not yet decayed into something else. 28. How many half-lives have passed? a) 1 b) 2 c) 3 d) 4 e) 5 29. If the half-life of the element is 26 seconds how much time has passed according to the diagram? a) 13 seconds b) 26 seconds c) 52 seconds d) 78 seconds e) 104 seconds ab) 130 seconds 30. How many grams will decay in the next half-life? a) 2 b) 5) c) 10 d) 20 e) 40
Radioactivity Test Review Problems 1. Bismuth-207 has a half-life of 35 years. a) How much of 48 grams of Bismuth-207 is unchanged after five half-lives? b) How much of 48 grams of Bismuth-207 has decayed after five half-lives? c) How much time has passed in five half-lives of Bismuth-207? 1. Total time Number of half-lives Unchanged Decayed 0 48g 0g 35 years 1 24g 24g 70 years 2 12g 36g 105 years 3 6g 42g 140 years 4 3g 45g 175 years 5 1.5g 46.5g 2. Cerium-137 has a half-life of 9 hours. a) How much of 14.8 grams of Cerium-137 is unchanged after four halflives? b) How much of 14.8 grams of Cerium-137 has decayed after four half-lives? c) How much time has passed in three half-lives of Cerium-137? 1. Total time Number of half-lives Unchanged Decayed 0 14.8 g 0g 9 hours 1 7.4g 7.4g 18 hours 2 3.7g 11.1g 27 hours 3 1.85g 12.95g 36 hours 4 0.925g 13.875g
3. What is the mass number of Berkelium-247? 247 4. What is the atomic number of Berkelium-247? 97 5. What is the correct symbol for Berkelium-247? Berkelium-247 undergoes alpha decay. 6. What is the mass number of the new element? 243 7. What is the atomic number of the new element? 95 8. What is the symbol for the new element? 9. What is the mass number of Antimony-125? 125 10. What is the atomic number of Antimony-125? 51 11. What is the correct symbol for Antimony-125? Antimony-125 undergoes beta decay. 12. What is the mass number of the new element? 125 13. What is the atomic number of the new element? 52 14. What is the symbol for the new element?