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Section Review 6.1 Part A Completion 1. properties 2. groups 3. periods or rows 4. atomic number 5. group 6. Metals 7. gases 8. metalloids 9. less 10. more Part B True-False 10. NT 12. AT 11. NT 13. NT Part C Matching 14. b 16. a 18. d 15. e 17. c Part D Questions and Problems 19. nitrogen and phosphorus are nonmetals; arsenic and antimony are metalloids; bismuth is a metal. 20. good conductors of heat and electric current; high luster; ductile; malleable; solids at room temperature 21. fluorine, bromine, iodine Section Review 6.2 Part A Completion 1. names 2. atoms 3. alkali metals 4. alkaline earth metals 5. representative elements 6. halogens 7. noble gases 8. transition metals 9. inner transition metals 10. p 11. not filled Part B True-False 12. ST 14. NT 13. NT 15. AT Part C Matching 16. f 19. d 21. c 17. e 20. b 22. a 18. g Part D Questions and Problems 23. Na, 3s1; Mg, 3s2; Al, 3s23p1; Si, 3s23p2; P, 3s23p3; S, 3s23p4; Cl, 3s23p5; Ar, 3s23p6 24. Oxygen: nonmetal, gas; Sulfur: nonmetal, solid; Selenium: nonmetal, solid; Tellurium: metalloid, solid; Polonium: metal, solid Section Review 6.3 Part A Completion 1. decrease 6. increases 2. increases 7. electrons 3. energy levels 8. smaller 4. charge 9. electronegativity 5. ionization 10. increases Part B True-False 11. ST 13. AT 12. AT 14. NT Part C Matching 15. d 17. f 19. e 16. c 18. a 20. b Part D Questions and Problems 21. a. Al d. Na b. S e. O c. Br 22. a. gallium c. chlorine b. oxygen d. bromine Practice Problems Section 6.1 1. c 2. a. nonmetal d. nonmetal b. metalloid e. metal c. metal 3. a 4. Li, Na, Rb, Cs, Fr 5. The three classes are as follows. 1) The metals: good conductors of heat and electric current; high luster when clean; malleable; ductile. 2) The nonmetals: poor conductors of heat and electric current; nonlustrous. Solid metals tend to be brittle. 3) The metalloids: elements that have properties similar to those of metals and nonmetals depending on the conditions. Section 6.2 1. Silicon is in the third period. Its first and second energy levels are full (1s22s22p6). It is the fourth element in the period; so its electron configuration must end in 3s23p2. The complete configuration is 1s22s22p63s23p2. 2. Iodine is located in period 5. Its first four energy levels are full. It is Group 4A; so its electron configuration must end in 5s25p5. The complete configuration is 1s22s22p63s23p63d104s24p64d105s25p5. 3. The configuration s2p3 indicates 5 electrons in the highest occupied energy level, which is a feature of Group 5A. 4. a. Elements in Group 5A have 5 electrons in their highest occupied energy level. The third period element in Group 5A is phosphorus. b. 4s24p5 represents the Group 7A element in period 4; this element is bromine. c. selenium. 5. a. The period 2 element with six electrons is oxygen. b. The period 4 element with 2 electrons is calcium. c. The element in period 4 with 2 electrons in the 4s sublevel and 10 electrons in the 3d sublevel is zinc. 6. Both Ne and Ar have a completely filled highest occupied energy level. They are in Group 8A, which is also known as the noble gases. Ne: 1s22s22p6 Ar: 1s22s22p63s23p6 7. The chemical and physical properties are largely determined by their electron configurations. Lithium in Group 1A has only 1 electron in its highest occupied energy level. Sulfur in Group 6A has 6 electrons in its highest occupied energy level. 8. Transition metals are elements whose highest occupied s sublevel and a nearby d sublevel contain electrons. The electron configurations for Ag and Fe are: Ag 1s22s22p63s23p64s24p64d105s1 Fe 1s22s22p63s23p63d64s2 Section 6.3 1. A magnesium atom is smaller than a sodium atom because the shielding effect is constant for elements in the same period, but the nuclear charge is greater in magnesium. So the electrons are drawn closer to the nucleus. Magnesium and calcium have the same number of electrons in their highest occupied energy level. A magnesium atom is smaller than a calcium atom because there are fewer occupied energy levels. 2. Astatine is in period 6. Tellurium is in period 5. Astatine is in Group 7A; tellurium is in Group 6A. Although atomic size decreases across a period, the additional occupied energy level in astatine significantly increases the size of the astatine atom as compared to the tellurium atom. The prediction is that atoms of astatine are larger than atoms of tellurium. 3. A chlorine atom is smaller than a magnesium atom because atomic size decreases from left to right across a period. When a magnesium atom reacts, it loses electrons from its highest occupied energy level. A magnesium ion has filled first and second levels. When chlorine reacts, it gains an electron in its highest occupied energy level. An ion with three occupied energy levels is larger than an ion with two occupied energy levels. 4. Across a period from left to right the principal energy level remains the same, but the nuclear charge increases. The increasing nuclear charge pulls the electrons closer to the nucleus, resulting in a smaller atomic radius. The trend is less pronounced as the number of electrons increases because the inner electrons shield the electrons in the highest occupied energy level. Atomic size increases as you move down a period because the electrons are added to higher principal energy levels. This enlarging effect is greater than the shrinking effect caused by increasing nuclear charge. 5. When a sulfur atom reacts to form an ion it adds two electrons while chlorine adds one electron. Sulfide and chloride ions have the same number of electrons. Because the chloride ion has the greater nuclear charge, it will be smaller than the sulfide ion. 6. Sodium’s first ionization energy is higher than that of potassium because ionization energy tends to decrease from top to bottom within a group. 7. Beryllium’s first ionization energy is greater because first ionization energy tends to increase from left to right across a period. 8. Barium is less electronegative than struntium because electronegativity values tend to decrease from top to bottom within a group. 9. Because magnesium has a relatively low first and second ionization energy, the removal of two electrons from magnesium is likely. The relatively high third ionization energy indicates the difficulty of removing a third electron from the filled second energy level. Magnesium normally forms an ion with a 2_ charge. 10. Because electronegativity decreases from top to bottom within a group, sulfur is less electronegative than oxygen. Because electronegativity increases from left to right across a period, fluorine is more electronegative than oxygen. The correct order for increasing electronegativity is then sulfur _ oxygen _ fluorine. Interpreting Graphics 6 1. 42 5. 2617 _C 2. table A 6. table B 3. atomic weight 7. 4 4. 0.53 g/cm3 8. physical state at room temperature; general class, e.g. transition metal; whether an element is not found in nature 9. In the periodic table elements with similar chemical and physical properties are grouped together in vertical columns. This organization helps scientists predict and explain similarities and differences in the properties of elements based on their underlying atomic structure. Listing the elements, in alphabetical order, makes it possible to quickly find information about the properties of a particular element without having to know the location of the element in the periodic table. 10. a. Li: Group 1A (or Group 1), period 2 Mo: Group 6B (or Group 6), period 5 b. No, because they are not located in the same group or family. c. Lithium, Li, is an alkali metal. Molybdenum, Mo, is a transition metal. d. Answers may include sodium, potassium, rubidium, cesium, and francium. 11. Check students’ work. Their keys need to include the color, mp, and bp, of the element (and the state if the square is not color coded for style).