Unit Four Worksheet Atoms, Bonding, and Chemical Reactions WS PS U4 Name Period Section 18.1 Matching. Match the definition with the term that best correlates to it. No definition will be used more than once. 1. Atom A) Small particles of matter that, in combinations of three, make protons and neutrons 2. Electron B) Area around the nucleus of an atom where one will be most likely to find the electrons of the atom 3. Electron cloud C) Atomic particle found in the nucleus that has a 1+ charge 4. Neutron D) Atomic particle found in the nucleus that has no charge E) Atomic particle found around the nucleus that has a 1 5. Nucleus charge F) Smallest particle of matter that has all the properties of 6. Proton the element to which it belongs G) Center of the atom 7. Quark Identification. Identify the symbols of each of the following elements. 8. Sodium: 14. Iodine: 9. Oxygen: 15. Mercury: 10. Silver: 16. Helium: 11. Potassium: 17. Iron: 12. Fluorine: 18. Hydrogen: 13. Phosphorus: 19. Carbon: 20. How were quarks discovered? 21. Describe the electron cloud model of the atom. page 1 WS PS U4
22. Explain how a rotating electric fan might be used to model the atom. Also explain how the rotating fan is unlike an atom. 23. Why has the atomic model changed over time? Section 18.2 Matching. Match the definition with the term that best correlates to it. No definition will be used more than once. 24. Atomic number A) Number of protons in an atom s nucleus B) Atom of the same element as another atom but with a 25. Atomic mass unit different number of neutrons in its nucleus C) Total number of protons and neutrons in the nucleus of 26. Average atomic mass an atom D) Weighted average mass all the isotopes of an element 27. Isotope E) Unit of measurement for the mass of each proton and neutron in an atom; also one-twelfth the mass of a 28. Mass number carbon atom Refer to the following two isotopes to fill in the table that follows and answer the questions that follow. Iridium-185 Iridium-192 185 77Ir 192 77Ir Isotopes of Iridium Characteristics Iridium-185 Iridium-192 Number of protons (p + ) / Atomic number 29. 33. Number of electrons (e - ) in a neutral atom of the element Number of neutrons 30. 34. 31. 35. Number of protons and neutrons / Mass number 32. 36. page 2 WS PS U4
37. How do iridium-185 and iridium-192 differ at the atomic level? Be specific. Section 18.3 Multiple Choice. Select the answer that best completes the statement and write the letter for that answer in the space provided. 38. 39. 40. 41. 42. 43. 44. 45. Each energy level of an atom has a maximum number of it can hold. (A) electrons (B) neutrons (C) quarks (D) protons Dot diagrams are used to represent. (A) atomic numbers (C) isotopes (B) atomic mass (D) outer level electrons Horizontal rows of the periodic table are called.. (A) clusters (B) families (C) periods (D) groups Elements that are gases, are brittle, and are poor conductors at room temperature are (A) metals (B) nonmetals (C) metalloids (D) isotopes The current periodic table of elements arranges elements in order of increasing. (A) atomic mass (C) number of neutrons (B) atomic number (D) alphabetical order When Dmitri Mendeleev arranged the elements, he arranged them in order of increasing. (A) atomic mass (C) number of neutrons (B) atomic number (D) alphabetical order Elements that are semiconductors, such as silicon and germanium, and can be found along the zig-zag line of the periodic table of elements are (A) metals (B) nonmetals (C) metalloids (D) isotopes Elements that are almost entirely solids, are generally shiny, and are good conductors at room temperature are (A) metals (B) nonmetals (C) metalloids (D) isotopes page 3 WS PS U4
Table Completion. Complete the following table with the information provided and using your periodic table of elements. Symbols of Elements Characteristics Sr Cl O Number of protons (p + ) / Atomic number 46. 51. 56. Number of electrons (e - ) in a neutral atom of the element Average atomic mass 47. 52. 57. 48. 53. 58. Number of electrons in outer most shell of neutral atom of element Electron dot diagram of neutral atom of element 49. 54. 59. 50. 55. 60. Short Answer. Answer the following question. 61. Why do noble gases rarely combine with atoms of any other element? Section 19.1 Matching. Match the definition with the term that best correlates to it. No definition will be used more than once. 62. Chemical formula A) H 2 O, NaCl, and C 6 H 12 O 6 are examples of this B) To have a complete outer shell of electrons 63. Chemical bond C) The sharing or transfer of electrons creates this 64. Chemically stable Identification. Identify the number of atoms of each element as specified in the formula shown. NaCl (sodium chloride) MgBr 2 (magnesium bromide) 65. Sodium: 67. Magnesium: 66. Chlorine: 68. Bromine: page 4 WS PS U4
C 12 H 22 O 11 (sucrose) Cr(SO 4 ) 3 (chromium (VI) sulfate) 69. Carbon: 72. Chromium: 70. Hydrogen: 73. Sulfur: 71. Oxygen: 74. Oxygen: 75. Why are some elements stable on their own while others are more stable in compounds? 76. Describe what happens to the properties of elements when atoms form compounds. 77. In what ways can a chemical bond form? Section 19.2 Study the diagram for questions 78 83. Assume atom A will lose some of its electrons to atom B. 78. How many electrons will atom A lose to atom B? 79. How many electrons will atom B gain from atom A? 80. What will be the new charge and amount of charge on atom A when it becomes ion A? 81. What will be the new charge and amount of charge on atom B when it becomes ion B? 82. What will be the total charge of the compound formed? page 5 WS PS U4
83. What type of bond will form? 84. Explain why an element s number of valence electrons is related to the A groups on the periodic table of elements. 85. Why do some covalent compounds have polar molecules while others have nonpolar molecules? Table Completion. Fill in the table based on the information provided. Characteristic Ionic compounds Covalent compounds How the compound is formed with electrons 86. 91. Smallest particle 87. 92. Usual state of matter at room temperature Formed by metals, nonmetals, metalloids? Example 88. 93. 89. 94. 90. 95. Section 24.1 Use the equation below to answer questions 96 97. 2AgNO 3 (aq) + Mg(s) 2Ag(s) + Mg(NO 3 ) 2 (aq) 96. What is the physical state of each of the reactants and the product of the reaction? AgNO 3 : Mg: Mg(NO 3 ) 2 : Ag: 97. According to the law of conservation of mass, if the total mass of the products in this chemical reaction is 14 g, what must the combined masses of the reactants be? page 6 WS PS U4
Write chemical equations for the following reactions in questions 98 100. 98. One unit of methane gas, CH 4, plus two units of oxygen gas, O 2, produce one unit of carbon dioxide gas, CO 2, and two units of liquid water, H 2 O. 99. One unit of aqueous aluminum sulfate, Al 2 (SO 4 ) 3, plus three units of aqueous barium chloride, BaCl 2, yield two units of aqueous aluminum chloride, AlCl 3, plus three units of solid barium sulfate, BaSO 4. 100. Two units of solid sodium metal plus one unit of chlorine gas (Cl 2 ) produce two units of solid sodium chloride, NaCl. Section 24.2 Balancing. Balance the following equations. If you need help, review the steps for balancing equations in your textbook and/or notes. If no coefficient is needed, write 1 in the blank. 101. H 2 (g) + Cl 2 (g) HCl(aq) 102. N 2 (g) + H 2 (g) NH 3 (g) 103. Li(s) + FeBr 2 (aq) LiBr(aq) + Fe(s) 104. Al(s) + HCl(aq) H 2 (g) + AlCl 3 (aq) 105. Li(s) + N 2 (g) Li 3 N(s) 106. Fe(s) + O 2 (g) FeO(s) 107. N 2 O 5 + H 2 O HNO 3 108. P + O 2 P 2 O 5 109. Fe(OH) 3 Fe 2 O 3 + H 2 O 110. Al + H 2 SO 4 Al 2 (SO 4 ) 3 + H 2 111. Use the law of conservation of mass to explain why a chemical equation must be balanced. 112. Why must one use coefficients to balance equations rather than simply change subscripts in a formula? page 7 WS PS U4
Section 24.3 Identification. Identify each of the following reactions as one of the following types of reactions: (A) synthesis, (B) decomposition, (C) single-displacement, or (D) double-displacement. 113. 4Fe(s) + 3O 2 (g) 2Fe 2 O 3 (s) 114. Zn(s) + 2HCl(aq) H 2 (g) + ZnCl 2 (aq) 115. 4C(s) + O 2 (g) + 6H 2 (g) 2C 2 H 6 O(s) 118. CdCO 3 (s) CdO(s) + CO 2 (g) 119. NiCl 2 (s) Ni(s) + Cl 2 (g) 120. 2Li(s) + H 2 O(l) 2LiOH(aq) + H 2 (g) 116. LiCl(aq) + KOH(aq) KCl(aq) + LiOH(aq) 121. Mg(s) + O 2 (g) Δ MgO(s) 117. MgCO 3 (aq) + 2HCl(aq) MgCl 2 (aq) + H 2 O(l) + CO 2 (g) Matching. Match the definition with the term that best correlates to it. No definition will be used more than once. 122. Synthesis reaction 123. Decomposition reaction 125. Single-displacement reaction 126. Double-displacement reaction 124. Precipitate A) Insoluble compound that comes out of solution during a double-displacement reaction B) Chemical reaction in which one substance breaks down into two or more substances C) Chemical reaction that produces a gas, water, precipitate, and/or compounds in solution when two aqueous ionic compounds are combined D) Chemical reaction in which two or more substances combine to form a different substance E) Chemical reaction in which one element replaces another element in a compound Short Answer. State whether each reaction will take place. Explain. 127. Au(s) + KNO 3 (aq) AuNO 3 (aq) + K(s) 128. 2Al(s) + 3H 2 SO 4 (aq) Al 2 (SO 4 ) 3 (aq) + 3H 2 (g) Section 24.4 Identification I. Identify each of the following reactions as involving the use of (C) a catalyst, (I) an inhibitor, or (N) neither. 129. Brushing the cut edges of fruits with lemon juice can prevent the darkening effect that contact with air can cause. 130. In the human body, proteins called enzymes help to speed up chemical processes. page 8 WS PS U4
131. Aluminum oxide, which forms on exposed aluminum, protects the aluminum from further reaction with air. 132. Food preservatives called BHT and BHA slow down the spoilage of certain foods. 133. Nickel is used to increase the rate of methane formation from the addition of hydrogen and carbon monoxide. Nickel does not permanently change. 134. Electricity passed through water causes the water to separate into hydrogen gas and oxygen gas. Identification II. Identify each of the following reactions as being (A) an endergonic reaction or (B) an exergonic reaction. 135. When a lit match is placed in alcohol, the alcohol ignites producing heat and light. 136. Energy in the form of electricity can be added to water to break apart the water molecules into hydrogen gas and oxygen gas. 137. A piece of coal placed in a furnace gives off heat and light before turning into ash. 138. When ammonium chloride mixes with water, the solution formed feels cold. 139. When sulfuric acid mixes with ammonium hydroxide, the solution formed feels hot. 140. What is the difference between an exothermic reaction and endothermic reaction? 141. What happens to a catalyst in a chemical reaction? page 9 WS PS U4