Atoms Ions and Compounds

Atoms, Ions, and Compounds MULTIPLE CHOICE 1. Who discovered electrons? a. Robert Boyle d. John Dalton b. Robert Millikan e. Albert Einstein c. Joseph John Thomson ANS: C DIF: Easy REF: 2.1 OBJ: Identify the scientists who contributed to the development of modern atomic theory. MSC: Factual 2. Who was the first scientist to determine the charge of an electron? a. Robert Boyle d. John Dalton b. Robert Millikan e. Albert Einstein c. Joseph John Thomson ANS: B DIF: Easy REF: 2.1 OBJ: Identify the scientists who contributed to the development of modern atomic theory. MSC: Factual 3. What is the correct symbol for an electron? a. d. b. e. c. ANS: A DIF: Easy REF: 2.1 OBJ: Write the complete symbols used for subatomic particles. MSC: Applied 4. What is the correct symbol for a proton? a. d. b. e. c. ANS: C DIF: Easy REF: 2.1 OBJ: Write the complete symbols used for subatomic particles. MSC: Applied 5. What is the correct symbol for a neutron? a. d. b. e. c. ANS: A DIF: Easy REF: 2.1 OBJ: Write the complete symbols used for subatomic particles. MSC: Applied 6. What is the correct symbol for an ? particle? a. d. b. e. c. ANS: D DIF: Medium REF: 2.1 OBJ: Write the complete symbols used for subatomic particles. MSC: Applied 7. In the Rutherford–Geiger–Marsden experiment, ? particles were projected at a thin film of __________ a. gold. d. sodium. b. silver. e. aluminum. c. platinum. ANS: A DIF: Easy REF: 2.1 OBJ: Identify and describe experiments that provided evidence to support modern atomic theory. MSC: Factual 8. In the atoms in the Rutherford–Geiger–Marsden experiment, the ? particles were repelled by __________ a. electrons. d. nuclei. b. protons. e. gravity. c. neutrons. ANS: D DIF: Easy REF: 2.1 OBJ: Identify and describe experiments that provided evidence to support modern atomic theory. MSC: Factual 9. Which one of the following experiments provided evidence that atoms contained small massive nuclei with positive charges? a. Bunsen and Kirchoff’s flame test b. Fraunhofer lines c. the Rutherford–Geiger–Marsden experiment d. Thomson’s experiments with cathode ray tubes e. Millikan’s oil-drop experiment ANS: C DIF: Easy REF: 2.1 OBJ: Identify and describe experiments that provided evidence to support modern atomic theory. MSC: Factual 10. Rutherford, Geiger, and Marsden’s experiment demonstrated that the volume of the nucleus is roughly what fraction of the volume occupied by the electrons? a. 1/10 d. 1/10,000 b. 1/100 e. 1/100,000 c. 1/1,000 ANS: D DIF: Easy REF: 2.1 OBJ: Compare the size of the nucleus with the size of the atom. MSC: Factual 11. If an atom had a radius of 100 m, it would be approximately the size of a football stadium. On this scale, what would be the radius of the atomic nucleus since the radius of the nucleus is approximately 10,000 times smaller than the radius of an atom? a. 1 mm, like a very dull pencil point d. 10 ??m, like a red blood cell b. 1 cm, like a dime e. 100 pm, like a real atom c. 10 cm, like your longest finger ANS: B DIF: Difficult REF: 2.1 OBJ: Compare the size of the nucleus with the size of the atom. MSC: Applied 12. Protons and neutrons are examples of __________ a. nuclei. d. isotopes. b. nuclides. e. charged particles. c. nucleons. ANS: C DIF: Easy REF: 2.2 OBJ: Identify the subatomic particles. MSC: Factual 13. The 4He nucleus is an example of __________ a. a nuclide. d. a neutron. b. an element. e. a nucleon. c. a proton. ANS: A DIF: Easy REF: 2.2 OBJ: Identify the subatomic particles. MSC: Factual 14. A atom has __________ protons, __________ neutrons, and __________ electrons. a. 17, 18, 19 d. 17, 18, 17 b. 17, 20, 17 e. 18, 17, 18 c. 17, 17, 20 ANS: D DIF: Easy REF: 2.2 OBJ: Decompose an atomic symbol to determine the number of protons, neutrons, and electrons. MSC: Applied 15. A ion has __________ protons, __________ neutrons, and __________ electrons. a. 8, 10, 8 d. 8, 8, 8 b. 8, 10, 10 e. 8, 16, 8 c. 8, 8, 10 ANS: C DIF: Easy REF: 2.2 OBJ: Decompose an atomic symbol to determine the number of protons, neutrons, and electrons. MSC: Applied 16. Which particle diagram is the best representation for a atom? a. c. b. d. ANS: B DIF: Easy REF: 2.2 OBJ: Identify how particles are distributed in an atom given its atomic symbol. MSC: Conceptual 17. Which particle-level diagram is the best representation of a ion? a. c. b. d. ANS: C DIF: Easy REF: 2.2 OBJ: Identify how particles are distributed in an atom given its atomic symbol. MSC: Conceptual 18. When cosmic rays strike atoms in the upper atmosphere, energetic neutrons are produced. These neutrons collide with nitrogen-14 atoms, producing carbon-14 atoms and hydrogen atoms. Which diagram represents the carbon-14 product? a. c. b. d. ANS: D DIF: Medium REF: 2.2 OBJ: Identify how particles are distributed in an atom given its name. MSC: Conceptual 19. Which statement best describes isotopes? a. They have the same atomic mass. b. They have the same total number of protons and neutrons. c. They have the same number of neutrons but a different number of protons. d. They have the same number of protons but a different number of neutrons. e. They have very different chemical reactivity. ANS: D DIF: Easy REF: 2.2 OBJ: Identify the feature that distinguishes one isotope from another. MSC: Factual 20. The average atomic mass of calcium is 40.078 amu. Which is the most abundant isotope of calcium? a. 40Ca d. 44Ca b. 42Ca e. 48Ca c. 43Ca ANS: A DIF: Medium REF: 2.3 OBJ: Given an average atomic mass, identify the isotope that is likely to be the most abundant. MSC: Conceptual 21. For each of the elements below, there are only two naturally occurring isotopes. Using information in your periodic table, identify the pair in which the heavier isotope is the more abundant one. a. 63Cu and 65Cu d. 79Br and 81Br b. 85Rb and 87Rb e. 14N and 15N c. 10B and 11B ANS: C DIF: Medium REF: 2.3 OBJ: Given an average atomic mass, identify the isotope that is likely to be the most abundant. MSC: Conceptual 22. For each of the elements below, there are only two naturally occurring isotopes. Using information in your periodic table, identify the pair in which the lighter isotope is the more abundant one. a. 6Li and 7Li d. 191Ir and 193Ir b. 79Br and 81Br e. 50V and 51V c. 10B and 11B ANS: B DIF: Medium REF: 2.3 OBJ: Given an average atomic mass, identify the isotope that is likely to be the most abundant. MSC: Conceptual 23. The average atomic mass of zinc is 65.39 amu. Given the data in the following table, what is the natural abundance of 66Zn? Isotope Mass (amu) Natural Abundance (%) 64Zn 63.9291 48.89 66Zn 65.9260 ? 67Zn 66.9271 4.11 68Zn 67.9249 18.56 70Zn 69.9253 0.62 a. 27.81% d. 2.781% b. 0.2781% e. 28.71% c. 50.00% ANS: A DIF: Medium REF: 2.3 OBJ: Determine the abundance of an isotope given the average mass, isotope masses, and abundances of the other isotopes. MSC: Applied 24. An unknown element is found to contain isotopes with the following masses and natural abundances: 38.9637 amu (93.08%), 39.9640 amu (0.012%), and 40.9618 amu (6.91%). Using these data, identify the element. a. S d. K b. Cl e. Ca c. Ar ANS: D DIF: Difficult REF: 2.3 OBJ: Determine the average atomic mass of an atom from data on the masses and natural abundances of its isotopes. MSC: Applied 25. A hypothetical element has two stable isotopes: one isotope has a mass of 106.9051 amu with an abundance of 48.183%, the other isotope has a mass of 108.9048 amu with an abundance of 51.825%. What is the average atomic mass of this element? a. 107.980 amu d. 107.950 amu b. 107.970 amu e. 107.940 amu c. 107.960 amu ANS: D DIF: Difficult REF: 2.3 OBJ: Determine the average atomic mass of an atom from data on the masses and natural abundances of its isotopes. MSC: Applied 26. The average atomic mass of lithium is 6.941 amu. Lithium has two naturally occurring isotopes, 6Li (7.52%) and 7Li (92.48%). The mass of 6Li is 6.0151 amu. What is the mass of 7Li? a. 7.016 amu d. 7.000 amu b. 0.926 amu e. 6.941 amu c. 6.001 amu ANS: A DIF: Difficult REF: 2.3 OBJ: Determine the mass of an isotope from the average mass and natural abundances of other isotopes. MSC: Applied 27. Zinc has five naturally occurring isotopes with an average mass of 65.39 amu. Three isotopes, in roughly equal amounts, account for 95% of zinc. Which isotope is most abundant? a. 64Zn, 63.9291 amu d. 68Zn, 67.9249 amu b. 66Zn, 65.9260 amu e. 70Zn, 69.9253 amu c. 67Zn, 66.9271 amu ANS: A DIF: Difficult REF: 2.3 OBJ: Given an average atomic mass, identify the isotope that is likely to be the most abundant. MSC: Conceptual 28. Enriched weapons-grade uranium consists of 80% uranium-235 (235.044 amu) and 20% uranium-238 (238.051 amu). What is the average atomic mass of weapons grade uranium assuming the percentages are exact? a. 235.044 amu d. 235.645 amu b. 236.547 amu e. 235.754 amu c. 238.051 amu ANS: D DIF: Difficult REF: 2.3 OBJ: Determine the average atomic mass of an atom from data on the masses and natural abundances of its isotopes. MSC: Applied 29. What is the symbol for sulfur? a. Si d. S b. Sc e. Sf c. Su ANS: D DIF: Easy REF: 2.4 OBJ: Convert between the name and symbol of an element. MSC: Factual 30. What is the symbol for magnesium? a. M d. Mo b. Mg e. Ma c. Mn ANS: B DIF: Easy REF: 2.4 OBJ: Convert between the name and symbol of an element. MSC: Factual 31. He is the symbol for __________ a. hydrogen. d. helium. b. hafnium. e. holmium. c. mercury. ANS: D DIF: Easy REF: 2.4 OBJ: Convert between the name and symbol of an element. MSC: Factual 32. Which of the following is an alkali metal? a. K d. Cu b. Mg e. Ca c. Al ANS: A DIF: Easy REF: 2.4 OBJ: Associate elements with the group to which they belong. MSC: Factual 33. Elements 21 through 30 are known as __________ a. alkaline earths. d. transition metals. b. chalcogens. e. rare earths. c. halides. ANS: D DIF: Easy REF: 2.4 OBJ: Associate elements with the group to which they belong. MSC: Factual 34. Calcium is an example of __________ a. an alkali metal. d. a halogen. b. a transition metal. e. a chalcogen. c. an alkaline earth metal. ANS: C DIF: Easy REF: 2.4 OBJ: Associate elements with the group to which they belong. MSC: Factual 35. Elements in group 17 (VIIA) are called __________ a. alkali metals. d. halogens. b. pnictogens. e. chalcogens. c. alkaline earth metal. ANS: D DIF: Easy REF: 2.4 OBJ: Associate elements with the group to which they belong. MSC: Factual 36. Elements in group 18 (VIIIA) are called __________ a. alkali metals. d. halogens. b. noble gases. e. chalcogens. c. alkaline earth metals. ANS: B DIF: Easy REF: 2.4 OBJ: Associate elements with the group to which they belong. MSC: Factual 37. Silicon is best described as a __________ a. metalloid. d. noble gas. b. metal. e. nonmetal. c. transition metal. ANS: A DIF: Easy REF: 2.4 OBJ: Classify/identify an element as a metal, metalloid, or nonmetal. MSC: Factual 38. Sodium is best described as a __________ a. metalloid. d. noble gas. b. metal. e. nonmetal. c. transition metal. ANS: B DIF: Easy REF: 2.4 OBJ: Classify/identify an element as a metal, metalloid, or nonmetal. MSC: Factual 39. Cobalt is best described as a __________ a. metalloid. d. noble gas. b. transition metal. e. nonmetal. c. chalcogen. ANS: B DIF: Easy REF: 2.4 OBJ: Identify the transition metals in the periodic table. MSC: Factual 40. Oxygen is best described as a __________ a. metalloid. d. noble gas. b. metal. e. nonmetal. c. transition metal. ANS: E DIF: Easy REF: 2.4 OBJ: Classify/identify an element as a metal, metalloid, or nonmetal. MSC: Factual 41. Based on its position in the periodic table, which atom would you predict to form a compound with two bromine atoms? a. sodium d. calcium b. aluminum e. carbon c. lithium ANS: D DIF: Easy REF: 2.4 OBJ: Identify combining ratios of atoms based on their positions in the periodic table. MSC: Applied 42. Based on its position in the periodic table, which atom would you predict to form a compound with one chlorine atom? a. boron d. calcium b. aluminum e. carbon c. lithium ANS: C DIF: Easy REF: 2.4 OBJ: Identify combining ratios of atoms based on their positions in the periodic table. MSC: Applied 43. What is the correct formula for the compound formed between sodium and iodine based on their positions in the periodic table? a. Na2I d. Na2I2 b. NaI2 e. Na3I c. NaI ANS: C DIF: Easy REF: 2.4 OBJ: Identify combining ratios of atoms based on their positions in the periodic table. MSC: Applied 44. The sixth period of the periodic table contains __________ elements. a. 18 d. 16 b. 32 e. 8 c. 24 ANS: B DIF: Difficult REF: 2.4 OBJ: Identify periods in the periodic table. MSC: Applied 45. Dalton’s law of multiple proportions deals with __________ a. the proportions of reacting chemicals that maximize the reaction rate. b. the total number of different compounds that can be made from two elements. c. the volumes of two elements that can combine to form two or more compounds. d. the masses of two elements that can combine to form two or more compounds. e. reactions that involve multiple steps. ANS: D DIF: Medium REF: 2.5 OBJ: Identify the meaning of Dalton’s law of multiple proportions. MSC: Conceptual 46. Dalton’s law of multiple proportions can be applied to __________ a. H2O and CO2. d. SO2 and CO. b. CO and NO. e. O2 and O3. c. PF3 and PF5. ANS: C DIF: Easy REF: 2.5 OBJ: Identify the meaning of Dalton's law of multiple proportions. MSC: Conceptual 47. Iron can form two sulfides: FeS and Fe2S3. Use Dalton’s law of multiple proportions to predict the ratio of the two masses of sulfur that combine with 100 g of iron in each case to form these compounds. a. 1:1 d. 2:3 b. 1:3 e. 3:4 c. 1:2 ANS: D DIF: Easy REF: 2.5 OBJ: Use Dalton’s law of multiple proportions to determine the combining ratio of elements in forming compounds. MSC: Applied 48. When 10.0 g of sulfur is combined with 10.0 g of oxygen, 20.0 g of sulfur dioxide is formed. What mass of oxygen would be required to convert 10.0 g of sulfur into sulfur trioxide? a. 5.0 g d. 30 g b. 10 g e. 20 g c. 15 g ANS: C DIF: Difficult REF: 2.5 OBJ: Use Dalton’s law of multiple proportions to determine the combining ratio of elements in forming compounds. MSC: Applied 49. Nitrogen and oxygen combine to form several different nitrogen oxides. In one case, 8.4 g of nitrogen reacted completely with 4.8 g of oxygen. In another case, 4.2 g of nitrogen reacted with 9.6 g of oxygen. Which pair of nitrogen oxides is consistent with these data? a. NO and N2O d. NO and N2O4 b. NO and NO2 e. N2O and N2O4 c. N2O and N2O5 ANS: E DIF: Difficult REF: 2.5 OBJ: Use Dalton’s law of multiple proportions to determine the combining ratio of elements in forming compounds. MSC: Applied 50. Which one of the following statements is not consistent with Dalton’s atomic theory of matter? a. Atoms of one element can be converted into atoms of another element. b. Each element is composed of atoms that are identical in size, mass, and chemical properties. c. Compounds are formed from different atoms in simple whole number ratios. d. Atoms of different elements can combine in several different proportions to make different compounds. e. Matter is discrete, as proposed by Democritus. ANS: A DIF: Easy REF: 2.5 OBJ: Identify the components of the modern atomic theory. MSC: Factual 51. Which has more mass: a lump of coal (assumed to be 100% carbon) or the carbon dioxide gas formed from burning the lump of coal? a. The lump of coal because it is a solid. b. The lump of coal because gases have little mass. c. The carbon dioxide gas because it occupies a much larger volume. d. The carbon dioxide gas because it includes oxygen that was added from the air. e. Both weigh the same because mass is conserved. ANS: D DIF: Easy REF: 2.5 OBJ: Apply conservation of mass to chemical reactions. MSC: Conceptual 52. Which contains more carbon by mass, 1 g of CO2 or 1 g of CO? a. CO2 b. CO c. Both contain the same mass of carbon. d. Both contain the same mass of carbon, but different masses of oxygen. ANS: B DIF: Medium REF: 2.5 OBJ: Apply conservation of mass to chemical reactions. MSC: Conceptual 53. Which has more mass, 1 g of CO2 gas or 1 g of CO gas? a. CO b. CO2 c. Both have the same mass. d. It depends on the density of these gases. e. It depends on the volume of these gases. ANS: C DIF: Easy REF: 2.5 OBJ: Apply the concepts of mass, volume, and density correctly. MSC: Conceptual 54. Which would produce the larger mass of carbon dioxide, CO2, when combined with oxygen: 1 g of pure carbon or 1 g of pure octane (C8H14)? Assume that all the carbon is converted to carbon dioxide in both cases. a. C b. C8H14 c. They would produce the same mass of CO2. d. It depends on the densities of the carbon and octane. ANS: A DIF: Difficult REF: 2.5 OBJ: Apply conservation of mass to chemical reactions. MSC: Conceptual 55. Which one of the following is an ionic compound? a. SO2 d. TiO2 b. ClO2 e. CO2 c. H2O ANS: D DIF: Easy REF: 2.5 OBJ: Classify a compound as molecular or ionic. MSC: Conceptual 56. Which one of the following is a molecular compound? Molecular compounds also are known as covalent compounds. a. Na2O d. CCl4 b. CaO e. Fe2O3 c. FeO ANS: D DIF: Easy REF: 2.5 OBJ: Classify a compound as molecular or ionic. MSC: Conceptual 57. Which of the following is most likely to exhibit covalent bonding? a. NaF d. CO2 b. CaCl2 e. NaCl c. Cs2O ANS: D DIF: Easy REF: 2.5 OBJ: Classify a compound as molecular or ionic. MSC: Conceptual 58. Identify the binary compound that has ionic bonding. a. H2O c. LiF b. NO d. CH4 ANS: C DIF: Easy REF: 2.7 OBJ: Classify a compound as molecular or ionic. MSC: Conceptual 59. Which one of the following is a cation? a. NO3– d. Na b. SO2 e. O2 c. Ca2+ ANS: C DIF: Easy REF: 2.5 OBJ: Distinguish between anions and cations. MSC: Factual 60. Which one of the following is an anion? a. Na+ d. Na b. CO2 e. O3 c. Cl– ANS: C DIF: Easy REF: 2.5 OBJ: Distinguish between anions and cations. MSC: Factual 61. What is the empirical formula for benzene, C6H6? a. CH d. CH3 b. C6H6 e. C6H c. C2H2 ANS: A DIF: Easy REF: 2.5 OBJ: Identify the meaning of an empirical formula. MSC: Applied 62. Active metals often form a protective oxide surface film that prevents further reaction of the metal with oxygen in the air. Which one of the following formulas for the metal oxide is not correct? a. Al2O3 is aluminum(III) oxide. d. MgO2 is magnesium oxide. b. Fe2O3 is iron(III) oxide. e. FeO is iron(II) oxide. c. Na2O is sodium oxide. ANS: D DIF: Medium REF: 2.6 OBJ: Convert between the name and formula of a binary ionic compound. MSC: Applied 63. What is the formula for sodium bromide? a. SBr d. NaBrO b. NaBr e. NaBr2 c. Na2Br ANS: B DIF: Easy REF: 2.6 OBJ: Convert between the name and formula of a binary ionic compound. MSC: Applied 64. What is the correct name for FeCl3? a. iron(III) chloride d. ferric trichloride b. iron trichloride e. iron chloride c. ferrum trichloride ANS: A DIF: Medium REF: 2.6 OBJ: Convert between the name and formula of a binary ionic compound. MSC: Applied 65. Manganese(IV) oxide is a brown insoluble solid often found as a product of reactions of potassium permanganate. What is the formula of manganese(IV) oxide? a. Mn4O d. MnO2 b. MnO4 e. Mn2O2 c. Mn(IV)O ANS: D DIF: Medium REF: 2.6 OBJ: Convert between the name and formula of a binary ionic compound. MSC: Applied 66. TiO2 is a white oxide used in paints. What is the proper name for TiO2? a. titanium oxide d. titanium oxoate b. titanium(IV) oxide e. titanium dioxide c. titanic acid ANS: B DIF: Medium REF: 2.6 OBJ: Convert between the name and formula of a binary ionic compound. MSC: Applied 67. Zinc oxide is found in ointments for the skin. What formula best describes this compound, which has Zn as a doubly charged cation? a. ZnO d. Zn2O2 b. Zn2O e. Zn2O3 c. ZnO2 ANS: A DIF: Medium REF: 2.6 OBJ: Convert between the name and formula of a binary ionic compound. MSC: Applied 68. Name the following oxides of nitrogen in this sequence: NO, N2O, NO2, N2O4. a. nitrogen monoxide, dinitrogen oxide, nitrogen dioxide, dinitrogen tetroxide b. nitrox, dinitrox, nitridiox, dinitritriox c. mononitrogen monoxide, dinitrogen monoxide, mononitrogen dioxide, dinitrogen tetraoxide d. nitrogen oxide, nitrogen(II) oxide, nitrogen oxide(II), nitrogen(II) oxide(IV) e. nitric oxide, nitrous oxide, nitrogen dioxide, nitrogen tetraoxide ANS: A DIF: Medium REF: 2.6 OBJ: Convert between names and formulas of molecular compounds. MSC: Applied 69. Which one of the formula-name combinations is not correct? a. sulfur monoxide: SO d. disulfur oxide: S2O b. sulfur dioxide: SO2 e. heptasulfur oxide: S6O c. sulfur trioxide: SO3 ANS: E DIF: Medium REF: 2.6 OBJ: Convert between names and formulas of molecular compounds. MSC: Applied 70. The Murrah Federal Building in Oklahoma City was destroyed on April 19, 1995, killing 168 people by a simple, but powerful, bomb made from 4800 lb of ammonium nitrate. What is the formula for ammonium nitrate? a. Am(NO3)2 d. NH4(NO3)2 b. Am(NO3) e. (NH4)2NO3 c. NH4NO3 ANS: C DIF: Medium REF: 2.6 OBJ: Convert between the name and the chemical formula of compounds with a polyatomic ion. MSC: Applied 71. Radium often is found in uranium ores and can be separated from solutions by precipitation as radium sulfate. What is the formula for radium sulfate? a. RnSO4 d. Ra2SO4 b. RaSO4 e. Ra(SO4)2 c. Rn2SO3 ANS: B DIF: Medium REF: 2.6 OBJ: Convert between the name and the chemical formula of compounds with a polyatomic ion. MSC: Applied 72. What is the proper name for Co(ClO4)3? a. cobalt trichlorate d. cobalt(III) perchlorate b. cobalt chlorate e. cobalt(III) chlorate c. cobaltous chlorate ANS: D DIF: Medium REF: 2.6 OBJ: Convert between the name and the chemical formula of compounds with a polyatomic ion. MSC: Applied 73. Buffer solutions that maintain certain levels of pH or acidity are widely used in biochemical experiments. One common buffer system uses sodium dihydrogenphosphate and sodium monohydrogenphosphate. What are the formulas of these two compounds? a. Na(HPO4) and Na(HPO4)2 c. Na2H2PO4 and NaHPO4 b. NaH2PO4 and Na2HPO4 d. NaPO4 and NaHPO4 ANS: B DIF: Difficult REF: 2.6 OBJ: Convert between the name and the chemical formula of compounds with a polyatomic ion. MSC: Applied 74. Aqua regia is a mixture of hydrochloric acid and nitric acid that is capable of dissolving gold. What are the formulas of these acids? a. HClO, HNO4 d. HCl, HNO3 b. HClO4, HNO3 e. HCl, HNO c. HCl, HNO2 ANS: D DIF: Easy REF: 2.6 OBJ: Convert between names and formulas of acids. MSC: Factual 75. Sodium nitrite, which is used in meat processing, has been implicated as a possible health hazard because it can react with amines present in meat to form trace quantities of carcinogenic nitrosamines. What is the formula of sodium nitrite? a. SNO d. Na2NO4 b. NaNO2 e. Na2NO2 c. NaNO3 ANS: B DIF: Medium REF: 2.6 OBJ: Convert between the name and the chemical formula of compounds with a polyatomic ion. MSC: Applied 76. According to the Big Bang theory, which statement about the origin of the elements is not correct? a. Initially, energy was transformed into electrons and other elementary particles. b. As the universe cooled, neutrons and protons were formed. c. Collisions of neutrons and protons produced deuterons, which then led to the formation of alpha particles. d. The nuclides of the elements then were formed by nuclear reactions in the interior of stars. e. These nuclear reactions all require the addition of energy to form the elements. ANS: E DIF: Medium REF: 2.7 OBJ: Describe the sequence of events that are part of the Big Bang theory. MSC: Factual 77. A high-energy particle with a negative charge is called a __________ particle? a. ? d. neutron b. ? e. positron c. ? ANS: B DIF: Easy REF: 2.7 OBJ: Identify the particles associated with nuclear reactions. MSC: Factual 78. The emission of a ? particle is associated with the __________ a. conversion of a neutron to a proton. d. decrease in mass number. b. conversion of a proton to a neutron. e. the formation of an isotope. c. increase in mass number. ANS: A DIF: Medium REF: 2.7 OBJ: Identify the products in a nuclear reaction. MSC: Factual 79. Two neutrons were walking down the street. One said, “Wait a minute…I think I lost a __________!” The other one asked, “Are you sure?” The first replied, “Yes, I’m positive!” a. positron c. ? ray b. ? particle d. neutrino ANS: B DIF: Medium REF: 2.7 OBJ: Identify the products in a nuclear reaction. MSC: Factual 80. A supernova event is the explosion caused by the collapse of a dying star that has run out of its nuclear fuel. These stars and events are responsible for __________ a. the production of elements heavier than iron-56. b. nuclear fission of heavy elements. c. the distribution of heavy elements throughout the universe. d. both a and c. e. both b and c. ANS: D DIF: Medium REF: 2.7 OBJ: Identify the source of elements heavier the iron-56. MSC: Factual 81. Which stellar nuclear reaction is not correctly written? a. d. b. e. c. ANS: C DIF: Difficult REF: 2.7 OBJ: Identify the source of elements heavier the iron-56. MSC: Applied SHORT ANSWER 1. In one sentence, describe the picture of the atom that emerged from the Rutherford-Geiger-Marsden experiment with alpha particles. ANS: The atom was pictured as consisting of a tiny, positively charged nucleus surrounded by a diffuse cloud of negatively charged electrons. DIF: Easy REF: 2.1 OBJ: Describe the picture of the atom that emerged from the Rutherford-Geiger-Marsden experiment with alpha particles. MSC: Factual 2. The average atomic mass of carbon is 12.01 amu. What is the average atomic mass of carbon in grams? (1 amu = 1.6605402 ? 10–27 kg) ANS: 1.994 ? 10–23 g DIF: Medium REF: 2.1 OBJ: Convert between atomic mass units, amu, and grams, g, given the equivalence statement. MSC: Applied 3. Write the complete atomic symbol with both a superscript and a subscript for a sodium ion that contains 11 protons, 10 electrons, and 12 neutrons. ANS: DIF: Easy REF: 2.2 OBJ: Write the complete atomic symbol for a given element or ion. MSC: Applied 4. 1H, 2H, and 3H are examples of __________ because they have different numbers of __________. ANS: isotopes / neutrons DIF: Easy REF: 2.2 OBJ: Identify the feature that distinguishes one isotope from another. MSC: Applied 5. What distinguishes one isotope from another? ANS: Isotopes have the same number of protons but different numbers of neutrons. DIF: Easy REF: 2.2 OBJ: Identify the feature that distinguishes one isotope from another. MSC: Applied 6. Nuclear reactors used for power generation require uranium enriched in uranium-235. What is the average atomic mass of enriched uranium consisting of exactly 3.0% uranium-235 (235.04 amu) and 97.0% uranium-238 (238.05 amu)? ANS: 237.96 amu DIF: Difficult REF: 2.3 OBJ: Calculate the average atomic mass of an element given the masses of the isotopes and their abundances. MSC: Applied 7. Boron, which has an average atomic mass of 10.81 amu, has two stable isotopes: boron-10 (19.78%) and boron-11 (80.22%). Boron-10 has an atomic mass of 10.0129 amu; what is the atomic mass of boron-11? ANS: 11.01 amu DIF: Difficult REF: 2.3 OBJ: Determine the mass of an isotope from the average mass and natural abundances of other isotopes. MSC: Applied 8. Give an example of an alkali metal. ANS: Sodium; answers will vary. DIF: Easy REF: 2.4 OBJ: Associate elements with the group to which they belong. MSC: Applied 9. Give an example of an alkaline earth metal. ANS: Calcium; answers will vary. DIF: Easy REF: 2.4 OBJ: Associate elements with the group to which they belong. MSC: Applied 10. Give an example of a halogen. ANS: Bromine; answers will vary. DIF: Easy REF: 2.4 OBJ: Associate elements with the group to which they belong. MSC: Applied 11. Give an example of a transition metal. ANS: Iron; answers will vary. DIF: Easy REF: 2.4 OBJ: Associate elements with the group to which they belong. MSC: Applied 12. Give an example of a nonmetal. ANS: Sulfur; answers will vary. DIF: Easy REF: 2.4 OBJ: Classify/identify elements as metals, metalloids, or nonmetals. MSC: Applied 13. Give an example of a metalloid (aka semimetal). ANS: Silicon; answers will vary. DIF: Easy REF: 2.4 OBJ: Classify/identify elements as metals, metalloids, or nonmetals. MSC: Applied 14. Give an example of an ionic compound. ANS: Sodium chloride, NaCl; answers will vary. DIF: Easy REF: 2.5 OBJ: Distinguish between ionic and covalent compounds. MSC: Applied 15. Give an example of a molecular compound (aka a covalent compound). ANS: Carbon dioxide, CO2; answers will vary. DIF: Easy REF: 2.5 OBJ: Distinguish between ionic and covalent compounds. MSC: Applied 16. A cation has a __________ charge, and an anion has a __________ charge. ANS: positive / negative DIF: Easy REF: 2.5 OBJ: Distinguish between anions and cations. MSC: Factual 17. Nitrogen and oxygen combine to form several different nitrogen oxides. Chemical analysis found that the N:O mass ratio in NO is 0.875. Two other nitrogen oxides were produced by reacting 8.4 g of nitrogen completely with 4.8 g of oxygen in one case and in another case by reacting 4.2 g of nitrogen with 9.6 g of oxygen. What are the empirical formulas of these two nitrogen oxides? ANS: N2O and NO2 DIF: Difficult REF: 2.5 OBJ: Use Dalton’s law of multiple proportions to determine combining ratios of elements in forming compounds. MSC: Applied 18. What is the chemical formula for manganese(IV) oxide? ANS: MnO2 DIF: Easy REF: 2.6 OBJ: Convert between the name and formula of a binary ionic compound. MSC: Applied 19. What is the correct name for CuCl2? ANS: Copper(II) chloride DIF: Easy REF: 2.6 OBJ: Convert between the name and formula of a binary ionic compound. MSC: Applied 20. What is the chemical formula for hexasulfur monoxide? ANS: S6O DIF: Easy REF: 2.6 OBJ: Convert between the name and the molecular formula of a binary molecular compound. MSC: Applied 21. What is the correct name for SO3? ANS: Sulfur trioxide DIF: Easy REF: 2.6 OBJ: Convert between the name and the molecular formula of a binary molecular compound. MSC: Applied 22. The evaporation of seawater gives a mixture of ionic compounds containing sodium combined with chloride, sulfate, carbonate, and hydrogen carbonate. Write the chemical formulas of these compounds. ANS: NaCl, Na2SO4, Na2CO3, NaHCO3 DIF: Difficult REF: 2.6 OBJ: Convert between the name and the chemical formula of compounds with a polyatomic ion. MSC: Applied 23. Iodine-137 decays to xenon by beta emission, which then decays to cesium-137. Write the nuclear reaction equations for these two decay processes. ANS: DIF: Difficult REF: 2.7 OBJ: Write nuclear reaction equations. MSC: Applied