The chemical properties of an element depend primarily on its number of valence electrons in

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1 HLLENGE PROLEMS omparing the Structures of toms and Ions Use with hapter 8, Section 8.1 The chemical properties of an element depend primarily on its number of valence electrons in its atoms. The noble gas elements, for example, all have similar chemical properties because the outermost energy levels of their atoms are completely filled. The chemical properties of ions also depend on the number of valence electrons. ny ion with a complete outermost energy level will have chemical properties similar to those of the noble gas elements. The fluoride ion (F ), for example, has a total of ten electrons, eight of which fill its outermost energy level. F has chemical properties, therefore, similar to those of the noble gas neon. Shown below are the Lewis electron dot structures for five elements: sulfur (S), chlorine (l), argon (r), potassium (K), and calcium (a). nswer the questions below about these structures. S l r K a 1. Write the atomic number for each of the five elements shown above. 2. Write the electron configuration for each of the five elements. 3. Which of the above Lewis electron dot structures is the same as the Lewis electron dot structure for the ion S 2? Explain your answer. 4. Which of the above Lewis electron dot structures is the same as that for the ion l? Explain your answer. 5. Which of the above Lewis electron dot structures is like that for the ion K? Explain your answer. opyright Glencoe/McGrawHill, a division of the McGrawHill ompanies, Inc. 6. Name an ion of calcium that has chemical properties similar to those of argon. Explain your answer. 8 hemistry: Matter and hange hapter 8 hallenge Problems

2 HPTER SSESSMENT Ionic ompounds Reviewing Vocabulary Match the definition in olumn with the term in olumn. olumn 1. Electrons that are free to move in metals 2. For a monatomic ion, is equal to the charge 3. The force that holds two atoms together 4. charged particle containing more than one atom 5. positively charged ion 6. negatively charged ion olumn a. alloy b. anion c. cation d. chemical bond e. delocalized electrons f. electrolyte opyright Glencoe/McGrawHill, a division of the McGrawHill ompanies, Inc. 7. n ionic compound whose aqueous solution conducts electricity 8. The name for most ionic compounds other than oxides 9. Represents the way electrons exist in metals 10. charged particle containing only one atom 11. The energy needed to separate the ions of an ionic compound 12. The electrostatic force that holds oppositely charged particles together 13. mixture of elements that has metallic properties 14. mixture formed when small atoms fill holes in a metallic crystal 15. polyatomic ion composed of an element bonded to at least one oxygen atom 16. Shows the simplest ratio of ions in an ionic compound 17. The attraction of a metallic cation for delocalized electrons g. electron sea model h. formula unit i. interstitial alloy j. ionic bond k. lattice energy l. metallic bond m. monatomic ion n. oxidation number o. oxyanion p. polyatomic ion q. salts hapter ssessment hemistry: Matter and hange hapter 8 43

3 HPTER SSESSMENT Understanding Main Ideas (Part ) The diagram on the right represents a lithium atom (group 1 of the periodic table) and a fluorine atom (group 17). Use the diagram to answer the questions that follow. 3 electrons 9 electrons Li 3 protons 9 protons F 1. What is the electron configuration of the neutral lithium atom? 2. What is the electron configuration of the neutral fluorine atom? 3. What happens to the lithium atom when it reacts with the fluorine atom? What is the electron configuration of the lithium after the change? 4. In terms of the electron arrangement, why is this change favorable for the lithium atom? 5. What happens to the fluorine atom when it reacts with the lithium atom? What is the electron configuration of the fluorine after the change? opyright Glencoe/McGrawHill, a division of the McGrawHill ompanies, Inc. 6. In terms of the electron arrangement, why is this change favorable for the fluorine atom? 7. What kind of compound is formed in the reaction? 8. What always happens to one or more electrons during a reaction that forms such a compound? 9. What are the formula and name of the product in this reaction? 10. What holds the atoms together in the compound? 11. What is the name for the overall threedimensional solid structure that samples of such compounds form? How are the particles generally arranged in such a structure? 12. How do the physical properties of such compounds differ from those typical of metals? hapter ssessment hemistry: Matter and hange hapter 8 45

4 STUY GUIE FOR ONTENT MSTERY Ionic ompounds Section 8.1 Forming hemical onds In your textbook, read about chemical bonds and formation of ions. Use each of the terms below just once to complete the passage. chemical bond electrons energy level ions noble gases nucleus octet pseudonoble gas formations valence opyright Glencoe/McGrawHill, a division of the McGrawHill ompanies, Inc. The force that holds two atoms together is called a(n) (1). Such an attachment may form by the attraction of the positively charged (2) of one atom for the negatively charged (3) of another atom, or by the attraction of charged atoms, which are called (4). The attractions may also involve (5) electrons, which are the electrons in the outermost (6). The (7) are a family of elements that have very little tendency to react. Most of these elements have a set of eight outermost electrons, which is called a stable (8). The relatively stable electron structures developed by loss of electrons in certain elements of groups 1, 2, 3, and 4 are called (9). For each statement below, write true or false. 10. positively charged ion is called an anion. 11. Elements in group 1 lose their one valence electron, forming an ion with a 1 charge. 12. Elements tend to react so that they acquire the electron structure of a halogen. 13. sodium atom tends to lose one electron when it reacts. 14. The electron structure of a zinc ion (Zn 2 ) is an example of a pseudonoble gas formation. 15. l ion is an example of a cation. 16. The ending ide is used to designate an anion. 17. Nonmetals form a stable outer electron configuration by losing electrons and becoming anions. Study Guide for ontent Mastery hemistry: Matter and hange hapter 8 43

5 STUY GUIE FOR ONTENT MSTERY Section 8.2 What is an ionic bond? In your textbook, read about forming ionic bonds and the characteristics of ionic compounds. ircle the letter of the choice that best completes the statement or answers the question. 1. n ionic bond is a. attraction of an atom for its electrons. b. attraction of atoms for electrons they share. c. a force that holds together atoms that are oppositely charged. d. the movement of electrons from one atom to another. 2. The formula unit of an ionic compound shows the a. total number of each kind of ion in a sample. b. simplest ratio of the ions. c. numbers of atoms within each molecule. d. number of nearest neighboring ions surrounding each kind of ion. 3. The overall charge of a formula unit for an ionic compound a. is always zero. c. is always positive. b. is always negative. d. may have any value. 4. How many chloride (l ) ions are present in a formula unit of magnesium chloride, given that the charge on a Mg ion is 2? a. onehalf b. one c. two d. four 5. Ionic bonds generally occur between a. metals. c. a metal and a nonmetal. b. nonmetals. d. noble gases. 6. Salts are examples of a. nonionic compounds. b. metals. c. nonmetals. d. ionic compounds. 7. threedimensional arrangement of particles in an ionic solid is called a(n) a. crystal lattice. b. sea of electrons. c. formula unit. d. electrolyte. 8. In a crystal lattice of an ionic compound, a. ions of a given charge are clustered together, far from ions of the opposite charge. b. ions are surrounded by ions of the opposite charge. c. a sea of electrons surrounds the ions. d. neutral molecules are present. opyright Glencoe/McGrawHill, a division of the McGrawHill ompanies, Inc. 44 hemistry: Matter and hange hapter 8 Study Guide for ontent Mastery

6 STUY GUIE FOR ONTENT MSTERY Section 8.2 continued 9. What is the relationship between lattice energy and the strength of the attractive force holding ions in place? a. The more positive the lattice energy is, the greater the force. b. The more negative the lattice energy is, the greater the force. c. The closer the lattice energy is to zero, the greater the force. d. There is no relationship between the two quantities. 10. The formation of a stable ionic compound from ions a. is always exothermic. c. is always endothermic. b. may be either exothermic or endothermic. d. neither absorbs nor releases energy. 11. In electron transfer involving a metallic atom and a nonmetallic atom during ion formation, which of the following is correct? a. The metallic atom gains electrons from the nonmetallic atom. b. The nonmetallic atom gains electrons from the metallic atom. c. oth atoms gain electrons. d. Neither atom gains electrons. Underline the word that correctly describes each property in ionic compounds. 12. Melting point Low High opyright Glencoe/McGrawHill, a division of the McGrawHill ompanies, Inc. 13. oiling point Low High 14. Hardness Hard Soft 15. rittleness Flexible rittle 16. Electrical conductivity in the solid state Good Poor 17. Electrical conductivity in the liquid state Good Poor 18. Electrical conductivity when dissolved in water Good Poor For each statement below, write true or false. 19. The crystal lattice of ionic compounds affects their melting and boiling points. 20. The lattice energy is the energy required to separate the ions of an ionic compound. 21. The energy of an ionic compound is higher than that of the separate elements that formed it. 22. Large ions tend to produce a more negative value for lattice energy than smaller ions do. 23. Ions that have larger charges tend to produce a more negative lattice energy than ions with smaller charges do. Study Guide for ontent Mastery hemistry: Matter and hange hapter 8 45

7 STUY GUIE FOR ONTENT MSTERY Section 8.3 hemical Formulas and Their Names In your textbook, read about communicating what is in a compound and naming ions and ionic compounds. Use each of the terms below just once to complete the passage. anion ate cation electrons zero lower right monatomic one oxidation number ite oxyanion polyatomic subscript oneatom ion is called a(n) (1) ion. The charge of such an ion is equal to the atom s (2), which is the number of (3) transferred to or from the atom to form the ion. In ionic compounds, the sum of the charges of all the ions equals (4). Ions made up of more than one atom are called (5) ions. If such an ion is negatively charged and includes one or more oxygen atoms, it is called a(n) (6). If two such ions can be formed that contain different numbers of oxygen atoms, the name for the ion with more oxygen atoms ends with the suffix (7). The name for the ion with fewer oxygen atoms ends with (8). In the chemical formula for any ionic compound, the chemical symbol for the (9) is written first, followed by the chemical symbol for the (10). (n) (11) is a small number used to represent the number of ions of a given element in a chemical formula. Such numbers are written to the (12) of the symbol for the element. If no number appears, the assumption is that the number equals (13). For each formula in olumn, write the letter of the matching name in olumn. olumn olumn 14. lo lo lo 17. l 18. lo 3 a. b. c. d. e. chlorate hypochlorite chloride perchlorate chlorite opyright Glencoe/McGrawHill, a division of the McGrawHill ompanies, Inc. 46 hemistry: Matter and hange hapter 8 Study Guide for ontent Mastery

8 STUY GUIE FOR ONTENT MSTERY Section 8.3 continued For each of the following chemical formulas, write the correct name of the ionic compound represented. You may refer to the periodic table on pages and Table 8.7 for help. 19. NaI 20. al K 2 S 22. MgO 23. LiHSO NH 4 r 25. a 3 N s 3 P 27. KrO Mg(lO) Li 2 O e 3 (PO 4 ) (NH 4 ) 2 O 3 opyright Glencoe/McGrawHill, a division of the McGrawHill ompanies, Inc. 32. NarO Fe 2 O Fe(IO 3 ) 2 For each of the following ionic compounds, write the correct formula for the compound. You may refer to the periodic table on pages and Table 8.7 for help. 35. beryllium nitride 36. nickel(ii) chloride 37. potassium chlorite 38. copper(i) oxide 39. magnesium sulfite 40. ammonium sulfide 41. calcium iodate 42. iron(iii) perchlorate 43. sodium nitride Study Guide for ontent Mastery hemistry: Matter and hange hapter 8 47

9 STUY GUIE FOR ONTENT MSTERY Section 8.4 Metallic onds and Properties of Metals In your textbook, read about metallic bonds. Use the diagram of metallic bonding to answer the following questions. 1. What is the name of the model of metallic bonding that is illustrated? 2. Why are the electrons in a metallic solid described as delocalized? 3. Which electrons from the metal make up the delocalized electrons? 4. re the metal atoms that are shown cations or anions? How can you tell? 5. How do the metallic ions differ from the ions that exist in ionic solids? 6. Explain what holds the metal atoms together in the solid. In your textbook, read about the properties of metals. For each property, write yes if the property is characteristic of most metals, or no if it is not. If the property is a characteristic of metals, explain how metallic bonding accounts for the property. 7. Malleable 8. rittle 9. Lustrous 10. High melting point 11. Low boiling point 12. uctile opyright Glencoe/McGrawHill, a division of the McGrawHill ompanies, Inc. 13. Poor conduction of heat 14. Good conduction of electricity 48 hemistry: Matter and hange hapter 8 Study Guide for ontent Mastery

10 Ionic ompounds Name: ate: opyright Glencoe/McGrawHill, a division of The McGrawHill ompanies, Inc. 1 Which of these is NOT a cation? Na l Mg 2 K This question covers TEKS 8. This question tests the material that was covered in the textbook on page 212. Use the diagram below to answer question 2. 2 The diagram represents the arrangement of atoms in a metallic solid. Scientists believe that electrons in the outer energy levels of the bonding metallic atoms are free to move from one atom to the next. ecause they are free to move, these electrons are often referred to as electron delocalized electrons lattice electrons malleable electrons valence electrons positive ion This question covers TEKS 8. This question tests the material that was covered in the textbook on page n atom with the electron configuration 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 is most likely a metal that forms a positive ion a metal that forms a negative ion a nonmetal that forms a positive ion a nonmetal that forms a negative ion This question covers TEKS 8. This question tests the material that was covered in the textbook on page 212. Use the table below to answer question 4. 4 The table shows the lattice energy for some ionic compounds. ased on these data, which of these compounds would require the most energy to separate the bonded ions? ompound Nal Kr LiF MgO Nal Kr LiF MgO Lattice Energy (kj/mol) This question covers TEKS 8. This question tests the material that was covered in the textbook on pages Reviewing hemistry: Mastering the TEKS hemistry: Matter and hange 15

11 Ionic ompounds, continued Name: ate: Use the diagram below to answer question 5. 6 When atoms of sodium (Na) and chlorine (l) combine to form salt (Nal), an ionic crystal is formed. The Na ion is smaller than the Na atom, while the l ion is larger than the l atom. Why? The Na and the l atoms both lost electrons. The Na and the l atoms both gained electrons. The Na atom lost an electron, while the l atom gained an electron. Ionic ompound The Na atom gained an electron, while the l atom lost an electron. This question covers TEKS 8 and 8. This question tests the material that was covered in the textbook on pages This apparatus was most likely designed to show that the formation of an ionic compound is an exothermic reaction ionic compounds are electrolytes ions have an electrical charge water is a good conductor of electricity This question covers TEKS 8. This question tests the material that was covered in the textbook on page What is the chemical formula for a compound formed from calcium ions (a 2 ) and chloride ions (l )? al a 2 l al 2 a 2 l 2 This question covers TEKS 2 and 8. This question tests the material that was covered in the textbook on pages Most transition metals have more than one oxidation number because they may lose d electrons when forming positive ions they may lose f electrons when forming ions their electron arrangements are unstable their electrons are closer to the nucleus This question covers TEKS 8. This question tests the material that was covered in the textbook on pages 213 and 222. opyright Glencoe/McGrawHill, a division of The McGrawHill ompanies, Inc. 16 hemistry: Matter and hange Reviewing hemistry: Mastering the TEKS