Unit 1 Practice Test Matching Match each item with the correct statement below. a. proton d. electron b. nucleus e. neutron c. atom 1. the smallest particle of an element that retains the properties of that element 2. a negatively charged subatomic particle 3. a subatomic particle with no charge Match each item with the correct statement below. a. mass number d. atomic mass b. atomic mass unit e. isotope c. atomic number 4. atoms with the same number of protons, but different numbers of neutrons in the nucleus of an atom 5. the total number of protons and neutrons in the nucleus of an atom 6. the number of protons in the nucleus of an element 7. the weighted average of the masses of the isotopes of an element 8. one-twelfth the mass of a carbon atom having six protons and six neutrons Match each item with the correct statement below. a. positron d. transuranium element b. alpha particle e. gamma radiation c. beta particle f. transmutation 9. element with atomic number greater than 92 10. energetic electron from decomposed neutron 11. high-energy photons emitted by a radioisotope 12. particle of charge +1 and mass equal to that of an electron 13. conversion of an atom of one element to an atom of another element Multiple Choice Identify the choice that best completes the statement or answers the question. 14. The smallest particle of an element that retains the properties of that element is a(n). a. atom c. proton b. electron d. neutron 15. Dalton's atomic theory included which idea? a. All atoms of all elements are the same size. b. Atoms of different elements always combine in one-to-one ratios. c. Atoms of the same element are always identical. d. Individual atoms can be seen with a microscope. 16. Which of the following is NOT a part of Dalton's atomic theory? a. All elements are composed of atoms. b. Atoms are always in motion.
c. Atoms of the same element are identical. d. Atoms that combine do so in simple whole-number ratios. 17. Which of the following was originally a tenet of Dalton's atomic theory, but had to be revised about a century ago? a. Atoms are tiny indivisible particles. b. Atoms of the same element are identical. c. Compounds are made by combining atoms. d. Atoms of different elements can combine with one another in simple whole number ratios. 18. All atoms are. a. positively charged, with the number of protons exceeding the number of electrons b. negatively charged, with the number of electrons exceeding the number of protons c. neutral, with the number of protons equaling the number of electrons d. neutral, with the number of protons equaling the number of electrons, which is equal to the number of neutrons 19. The particles that are found in the nucleus of an atom are. a. neutrons and electrons c. protons and neutrons b. electrons only d. protons and electrons 20. The atomic number of an element is the total number of which particles in the nucleus? a. neutrons c. electrons b. protons d. protons and electrons 21. The sum of the protons and neutrons in an atom equals the. a. atomic number c. atomic mass b. nucleus number d. mass number 22. All atoms of the same element have the same. a. number of neutrons c. mass numbers b. number of protons d. mass 23. Isotopes of the same element have different. a. numbers of neutrons c. numbers of electrons b. numbers of protons d. atomic numbers 24. The mass number of an element is equal to. a. the total number of electrons in the nucleus b. the total number of protons and neutrons in the nucleus c. less than twice the atomic number d. a constant number for the lighter elements 25. Using the periodic table, determine the number of neutrons in O. a. 4 c. 16 b. 8 d. 24 26. How many protons, electrons, and neutrons does an atom with atomic number 50 and mass number 125 contain? a. 50 protons, 50 electrons, 75 neutrons c. 120 neutrons, 50 protons, 75 electrons b. 75 electrons, 50 protons, 50 neutrons d. 70 neutrons, 75 protons, 50 electrons 27. Which of the following statements is NOT true? a. Atoms of the same element can have different masses. b. Atoms of isotopes of an element have different numbers of protons. c. The nucleus of an atom has a positive charge. d. Atoms are mostly empty space. 28. If E is the symbol for an element, which two of the following symbols represent isotopes of the same element?
1. E 2. E 3. E 4. E a. 1 and 2 c. 1 and 4 b. 3 and 4 d. 2 and 3 29. How is the number of neutrons in the nucleus of an atom calculated? a. Add the number of electrons and protons together. b. Subtract the number of electrons from the number of protons. c. Subtract the number of protons from the mass number. d. Add the mass number to the number of electrons. 30. Which of the following is necessary to calculate the atomic mass of an element? a. the atomic mass of carbon-12 b. the atomic number of the element c. the relative masses of the element s protons and neutrons d. the masses of each isotope of the element 31. The element coppper has naturally occuring isotopes with mass numbers of 63 and 65. the average atomic mass is 64.93. Which of the following is most abundant? a. Cu-62 c. Cu-63 b. Cu-64 d. Cu-65 32. Nitrogen has two natural occuring isotopes: N-14 and N-15. The average atomic mass of Nitrogen is 14.00674 amu. What is the approximate percentage of N-15? a. 99 % c. 1% b. 50 % d. 75 % 33. Which is the most susceptible to damage from ionizing radiation? a. soft tissue c. wood b. paper d. lead 34. The charge on a gamma ray is. a. +2 c. 0 b. 1 d. 2 35. The least penetrating form of radiation is. a. beta radiation c. alpha radiation b. gamma radiation d. X rays 36. Ionizing radiation that consists of helium nuclei is. a. X radiation c. beta radiation b. gamma radiation d. alpha radiation 37. What is the change in atomic number when an atom emits a beta particle? a. decreases by 2 c. increases by 2 b. decreases by 1 d. increases by 1 38. Which symbol is used for an alpha particle? a. He c. He b. He d. He 39. Which of the following materials is necessary to stop a beta particle? a. three feet of concrete c. thin pieces of wood b. three inches of lead d. single sheet of paper 40. Which type of ionizing radiation can be blocked by clothing? a. beta radiation c. gamma radiation b. X radiation d. alpha radiation 41. If an isotope decays by the process of beta emission,.
a. the mass number changes b. the atomic number changes c. protons are given off d. the number of neutrons remains the same 42. What particle is needed to complete this nuclear reaction? Rn Po + _ a. He c. H b. e d. n 43. A transmutation reaction must always involve a(n). a. change in the number of electrons in the atom b. decrease in the number of neutrons in the nucleus of an atom c. increase in the number of neutrons in the nucleus of an atom d. change in the number of protons in a nucleus of an atom 44. Matter is not conserved in a nuclear reaction because a. matter is converted to energy c. matter is converted to gas b. matter is never conserved d. the statement above is false Short Answer 45. List the number of protons, neutrons, and electrons in C. 46. The element chromium has four naturally occurring isotopes. Use the relative abundance of each to calculate the average atomic mass of chromium. Cr = 4.34%, Cr = 83.79%, Cr = 9.50%, Cr = 2.37%. 47. If the half-life of a radioactive material is 8 years, how many years will it take for one half of the original amount of material to decay? 48. The radioisotope radon-222 has a half-life of 3.8 days. How much of a 73.9-g sample of radon-222 would be left after approximately 23 days? 49. The concentration of carbon-14 in a piece of wood from an ancient burial mound indicates that two half-lives of this radioisotope have passed. If the half-life (t ) for carbon-14 is 5730 years, approximately how many years ago did this sample of wood die? Numeric Response 50. What is the relative charge carried by an electron? 51. What is the relative charge of a proton? 52. Use the periodic table to determine the number of electrons in a neutral atom of lithium. 53. Use the periodic table to determine the number of protons in an atom of barium. 54. What is the total number of subatomic particles in the nucleus of an atom of Bi? 55. Determine the number of electrons in an atom of iridium.
56. What is the mass number for an oxygen atom that has 10 neutrons in its nucleus? 57. What is the approximate ratio of neutrons to protons for stable atoms below atomic number 20? 58. Above which atomic number are all nuclei radioactive? 59. Above which atomic number are the transuranium elements located? Essay 60. What observations by Rutherford led to the hypothesis that atoms are mostly empty space, and that almost all of the mass of the atom is contained in an atomic nucleus? 61. Describe alpha particles, beta particles, and gamma rays. Indicate how the atomic number and atomic mass number change when a radioisotope decays to produce alpha, beta, or gamma radiation.
Unit 1 Practice Test Answer Section MATCHING 1. ANS: C PTS: 1 DIF: L1 REF: p. 101 p. 102 OBJ: 4.1.1 4.1.2 2. ANS: D PTS: 1 DIF: L1 REF: p. 104 OBJ: 4.2.1 3. ANS: E PTS: 1 DIF: L1 REF: p. 106 OBJ: 4.2.1 4. ANS: E PTS: 1 DIF: L1 REF: p. 112 5. ANS: A PTS: 1 DIF: L1 REF: p. 111 6. ANS: C PTS: 1 DIF: L1 REF: p. 110 7. ANS: D PTS: 1 DIF: L1 REF: p. 114 OBJ: 4.3.3 8. ANS: B PTS: 1 DIF: L1 REF: p. 114 OBJ: 4.3.3 9. ANS: D PTS: 1 DIF: L1 REF: p. 808 OBJ: 25.1.1 10. ANS: C PTS: 1 DIF: L1 REF: p. 801 11. ANS: E PTS: 1 DIF: L1 REF: p. 802 12. ANS: A PTS: 1 DIF: L1 REF: p. 804 13. ANS: F PTS: 1 DIF: L1 REF: p. 807 OBJ: 25.2.3 MULTIPLE CHOICE 14. ANS: A PTS: 1 DIF: L1 REF: p. 101 p. 102 OBJ: 4.1.1 4.1.2 15. ANS: C PTS: 1 DIF: L2 REF: p. 102 OBJ: 4.1.2 16. ANS: B PTS: 1 DIF: L2 REF: p. 102 OBJ: 4.1.2 17. ANS: A PTS: 1 DIF: L2 REF: p. 104 OBJ: 4.1.2 18. ANS: C PTS: 1 DIF: L3 REF: p. 106 OBJ: 4.2.1 19. ANS: C PTS: 1 DIF: L2 REF: p. 106 p. 107 OBJ: 4.2.1 4.2.2 STA: c4.8a TOP: testout1
20. ANS: B PTS: 1 DIF: L1 REF: p. 110 21. ANS: D PTS: 1 DIF: L1 REF: p. 111 STA: C4.8A TOP: testout1 22. ANS: B PTS: 1 DIF: L1 REF: p. 110 STA: C4.10b TOP: testout1 23. ANS: A PTS: 1 DIF: L1 REF: p. 112 p. 113 24. ANS: B PTS: 1 DIF: L2 REF: p. 111 25. ANS: B PTS: 1 DIF: L2 REF: p. 111 26. ANS: A PTS: 1 DIF: L2 REF: p. 111 27. ANS: B PTS: 1 DIF: L2 REF: p. 110 p. 112 p. 113 STA: C4.8B TOP: testout1 28. ANS: C PTS: 1 DIF: L2 REF: p. 112 STA: C4.10a, C4.10e TOP: testout1 29. ANS: C PTS: 1 DIF: L2 REF: p. 111 OBJ: 4.3.2 30. ANS: D PTS: 1 DIF: L2 REF: p. 116 OBJ: 4.3.3 STA: C4.10c TOP: testout1 31. ANS: D PTS: 1 STA: C4.10d TOP: testout1 32. ANS: C PTS: 1 33. ANS: A PTS: 1 DIF: L1 REF: p. 800 p. 802 34. ANS: C PTS: 1 DIF: L1 REF: p. 800 35. ANS: C PTS: 1 DIF: L1 REF: p. 802 36. ANS: D PTS: 1 DIF: L1 REF: p. 800 37. ANS: D PTS: 1 DIF: L2 REF: p. 801 38. ANS: D PTS: 1 DIF: L2 REF: p. 800 39. ANS: C PTS: 1 DIF: L2 REF: p. 802 40. ANS: D PTS: 1 DIF: L2 REF: p. 800 p. 801 p. 802 41. ANS: B PTS: 1 DIF: L2 REF: p. 801 OBJ: 25.2.1 42. ANS: A PTS: 1 DIF: L2 REF: p. 801 OBJ: 25.2.1 STA: c2.r5b TOP: testout1 43. ANS: D PTS: 1 DIF: L3 REF: p. 807 OBJ: 25.2.3 44. ANS: A PTS: 1 STA: c3.5a TOP: testout1
SHORT ANSWER 45. ANS: protons: 6; neutrons: 7; electrons: 6 PTS: 1 DIF: L2 REF: p. 110 p. 111 4.3.2 46. ANS: 50 amu 0.0434 = 2.17 amu 52 amu 0.8379 = 43.57 amu 53 amu 0.0950 = 5.04 amu 54 amu 0.0237 = 1.28 amu _ = 52.06 amu 52 amu PTS: 1 DIF: L3 REF: p. 116 p. 117 OBJ: 4.3.3 47. ANS: 8 years PTS: 1 DIF: L1 REF: p. 804 OBJ: 25.2.2 48. ANS: 23 days/3.8 days = approximately 6 half-lives have passed. 73.9 g (0.5)^6 = 1.2 g remaining. PTS: 1 DIF: L3 REF: p. 804 p. 805 OBJ: 25.2.2 49. ANS: 11,460 years ago PTS: 1 DIF: L3 REF: p. 806 OBJ: 25.2.2 NUMERIC RESPONSE 50. ANS: 1 PTS: 1 DIF: L1 REF: p. 105 OBJ: 4.2.1 51. ANS: 1+ PTS: 1 DIF: L1 REF: p. 106 OBJ: 4.2.1 52. ANS: 3 PTS: 1 DIF: L1 REF: p. 110 53. ANS: 56 PTS: 1 DIF: L1 REF: p. 110 54. ANS: 209
PTS: 1 DIF: L1 REF: p. 111 55. ANS: 77 PTS: 1 DIF: L1 REF: p. 112 56. ANS: 18 PTS: 1 DIF: L2 REF: p. 111 57. ANS: 1 PTS: 1 DIF: L2 REF: p. 803 OBJ: 25.2.1 58. ANS: 83 PTS: 1 DIF: L1 REF: p. 804 OBJ: 25.2.3 59. ANS: 92 PTS: 1 DIF: L1 REF: p. 808 OBJ: 25.2.3 ESSAY 60. ANS: Rutherford s gold-foil experiment led to this hypothesis. Alpha particles were observed to mostly pass through a gold foil, which suggests that the volume of individual gold atoms consists mainly of empty space. The observation that some alpha particles were scattered at large angles led to the suggestion that the gold atom has a central core, or nucleus, composed of a concentrated mass capable of deflecting the alpha particles. PTS: 1 DIF: L3 REF: p. 107 OBJ: 4.2.2 61. ANS: Alpha particles are helium nuclei; they have 2 protons and 2 neutrons. Alpha particles have relatively low energy and are the least penetrating of the three types of ionizing radiation. Beta particles are fast-moving electrons that are intermediate in energy and penetrating power. Gamma rays are electromagnetic radiation in the form of high-energy photons. Alpha particle emission reduces the atomic number of a radioisotope by 2, and the atomic mass number by 4. Beta particle emission increases atomic number by 1 and does not change the atomic mass number. Gamma ray emission neither alters the atomic mass number nor the atomic number. PTS: 1 DIF: L2 REF: p. 800 p. 801 p. 802 25.2.1