1. © 2015 Pearson Education, Inc. James F. Kirby Quinnipiac University Hamden, CT Lecture Presentation Chapter 7 Periodic Properties of the Elements

2. © 2015 Pearson Education, Inc. LESSON 1 7-1: Development of the Periodic Table

6. Periodic Properties of the Elements © 2015 Pearson Education, Inc. Development of the Periodic Table Dmitri Mendeleev and Lothar Meyer independently came to the same conclusion about how elements should be grouped.

7. Periodic Properties of the Elements © 2015 Pearson Education, Inc. Mendeleev and the Periodic Table Chemists mostly credit Mendeleev because he also used chemical properties to organize the table and predicted some missing elements and their expected properties, including germanium.

8. Periodic Properties of the Elements © 2015 Pearson Education, Inc. Atomic Number Mendeleev’s table was based on atomic masses. It was the most fundamental property of elements known at the time. About 35 years later, the nuclear atom was discovered by Ernest Rutherford. Henry Moseley developed the concept of atomic number experimentally. The number of protons was considered the basis for the periodic property of elements.

9. Periodic Properties of the Elements © 2015 Pearson Education, Inc. LESSON 2 7-2: Effective Nuclear Charge

10. Periodic Properties of the Elements © 2015 Pearson Education, Inc. We will discuss a fundamental property that leads to many of the trends that we will discuss later, effective nuclear charge.

11. Periodic Properties of the Elements © 2015 Pearson Education, Inc. Effective Nuclear Charge Many properties depend on attractions between valence electrons and the nucleus. Electrons are both attracted to the nucleus and repelled by other electrons. The forces an electron experiences depend on both factors.

12. Periodic Properties of the Elements © 2015 Pearson Education, Inc. Effective Nuclear Charge  The effective nuclear charge, Z eff, is found this way: Z eff = Z − S where Z is the atomic number and S is a screening constant, usually close to the number of inner electrons.  Effective nuclear charge is a periodic property: o It increases across a period. o It decreases down a group.

13. Effective nuclear charge (Z eff ) is the “positive charge” felt by an electron. Na Mg Al Si 11 12 13 14 10 1 2 3 4 186 160 143 132 Z eff Core Z Radius Z eff = Z -  0 <  < Z (shielding constant) Z eff  Z – number of inner or core electrons For a Period as Z eff increases radius decreases

14. Periodic Properties of the Elements © 2015 Pearson Education, Inc. Effective Nuclear Charge Increases across a Period

15. Periodic Properties of the Elements © 2015 Pearson Education, Inc. LESSON 3 7-3: Size of Atoms and Ions

16. Periodic Properties of the Elements © 2015 Pearson Education, Inc. Periodicity Periodicity is the repetitive pattern of a property for elements based on atomic number. The following properties are discussed in this chapter: –Sizes of atoms and ions –Ionization energy –Electron affinity –Some group chemical property trends

17. Periodic Properties of the Elements © 2015 Pearson Education, Inc. What Is the Size of an Atom? The nonbonding atomic radius or van der Waals radius is half of the shortest distance separating two nuclei during a collision of atoms.

18. Periodic Properties of the Elements © 2015 Pearson Education, Inc. Sizes of Atoms  The bonding atomic radius is half the internuclear distance when atoms are bonded.  The bonding atomic radius tends to — decrease from left to right across a period (Z eff ↑ ). — increase from top to bottom of a group (n ↑).

20. Atomic Radii

22. Periodic Properties of the Elements © 2015 Pearson Education, Inc. Sizes of Ions Determined by interatomic distances in ionic compounds Ionic size depends on –the nuclear charge. –the number of electrons. –the orbitals in which electrons reside.

23. Periodic Properties of the Elements © 2015 Pearson Education, Inc. Sizes of Ions Cations are smaller than their parent atoms: –The outermost electron is removed and repulsions between electrons are reduced. Anions are larger than their parent atoms: –Electrons are added and repulsions between electrons are increased.

24. Cation is always smaller than atom from which it is formed. Anion is always larger than atom from which it is formed.

26. Periodic Properties of the Elements © 2015 Pearson Education, Inc. Size of Ions— Isoelectronic Series In an isoelectronic series, ions have the same number of electrons. Ionic size decreases with an increasing nuclear charge.  An Isoelectronic Series (10 electrons) Note increasing nuclear charge with decreasing ionic radius as atomic number increases O 2– F–F– Na + Mg 2+ Al 3+ 1.26 Å1.19 Å1.16 Å0.86 Å0.68 Å

27. Periodic Properties of the Elements © 2015 Pearson Education, Inc. Hwk: page 290 - 296 : 14, 25, 27, 29, 34

28. Periodic Properties of the Elements © 2015 Pearson Education, Inc. LESSON 4 7-4: Ionization Energy

29. Periodic Properties of the Elements © 2015 Pearson Education, Inc. Ionization Energy (I) The ionization energy is the minimum energy required to remove an electron from the ground state of a gaseous atom or ion. –The first ionization energy is that energy required to remove the first electron. –The second ionization energy is that energy required to remove the second electron, etc. Note: the higher the ionization energy, the more difficult it is to remove an electron!

30. Ionization energy is the minimum energy (kJ/mol) required to remove an electron from a gaseous atom in its ground state. I 1 + X (g) X + (g) + e - I 2 + X + (g) X 2 + (g) + e - I 3 + X 2+ (g) X 3 + (g) + e - I 1 first ionization energy I 2 second ionization energy I 3 third ionization energy I 1 < I 2 < I 3

31. Filled n=1 shell Filled n=2 shell Filled n=3 shell Filled n=4 shell Filled n=5 shell

32. General Trend in First Ionization Energies Increasing First Ionization Energy

33. Periodic Properties of the Elements © 2015 Pearson Education, Inc. Ionization Energy It requires more energy to remove each successive electron. When all valence electrons have been removed, it takes a great deal more energy to remove the next electron.

34. Periodic Properties of the Elements © 2015 Pearson Education, Inc. Periodic Trends in First Ionization Energy (I 1 ) 1) I 1 generally increases across a period. 2) I 1 generally decreases down a group. 3)The s- and p-block elements show a larger range of values for I 1. (The d-block generally increases slowly across the period; the f-block elements show only small variations.)

35. Periodic Properties of the Elements © 2015 Pearson Education, Inc. Factors that Influence Ionization Energy  Smaller atoms have higher I values.  I values depend on effective nuclear charge and average distance of the electron from the nucleus.

36. Periodic Properties of the Elements © 2015 Pearson Education, Inc. Irregularities in the General Trend The trend is not followed when the added valence electron in the next element  enters a new sublevel (higher energy sublevel);  is the first electron to pair in one orbital of the sublevel (electron repulsions lower energy).

37. Periodic Properties of the Elements © 2015 Pearson Education, Inc. Electron Configurations of Ions Cations: The electrons are lost from the highest energy level (n value).  Li + is 1s 2 (losing a 2s electron).  Fe 2+ is 1s 2 2s 2 2p 6 3s 2 3p 6 3d 6 (losing two 4s electrons). Anions: The electron configurations are filled to ns 2 np 6 ; e.g., F – is 1s 2 2s 2 2p 6 (gaining one electron in 2p).

38. Periodic Properties of the Elements © 2015 Pearson Education, Inc. LESSON 5 7-5: Electron Affinity

39. Periodic Properties of the Elements © 2015 Pearson Education, Inc. Electron Affinity  Electron affinity is the energy change accompanying the addition of an electron to a gaseous atom: Cl + e −  Cl −  It is typically exothermic, so, for most elements, it is negative!

40. Periodic Properties of the Elements © 2015 Pearson Education, Inc. General Trend in Electron Affinity  Not much change in a group.  Across a period, it generally increases. Three notable exceptions include the following: 1)Group 2A: s sublevel is full! 2)Group 5A: p sublevel is half-full! 3)Group 8A: p sublevel is full! Note: the electron affinity for many of these elements is positive (X – is unstable).

41. Periodic Properties of the Elements © 2015 Pearson Education, Inc. Electron affinity is the negative of the energy change that occurs when an electron is accepted by an atom in the gaseous state to form an anion. X (g) + e - X - (g) F (g) + e - X - (g) O (g) + e - O - (g)  H = -328 kJ/mol EA = +328 kJ/mol  H = -141 kJ/mol EA = +141 kJ/mol

42. Periodic Properties of the Elements © 2015 Pearson Education, Inc.

43. Periodic Properties of the Elements © 2015 Pearson Education, Inc. Hwk: page 290 - 296 : 38, 41, 42, 43, 45, 47

44. Periodic Properties of the Elements © 2015 Pearson Education, Inc. LESSON 6 7-6: Metals, Nonmetals, and Metalloids

45. Periodic Properties of the Elements © 2015 Pearson Education, Inc. Metal, Nonmetals, and Metalloids

46. Periodic Properties of the Elements © 2015 Pearson Education, Inc.

47. Periodic Properties of the Elements © 2015 Pearson Education, Inc. Metals Differ from Nonmetals Metals tend to form cations. Nonmetals tend to form anions.

48. Periodic Properties of the Elements © 2015 Pearson Education, Inc. Metals  Most of the elements in nature are metals.  Properties of metals:  Shiny luster  Conduct heat and electricity  Malleable and ductile  Solids at room temperature (except mercury)  Low ionization energies/form cations easily

49. Periodic Properties of the Elements © 2015 Pearson Education, Inc. Metal Chemistry Compounds formed between metals and nonmetals tend to be ionic. Metal oxides tend to be basic.

50. Periodic Properties of the Elements © 2015 Pearson Education, Inc. Nonmetals Nonmetals are found on the right hand side of the periodic table. Properties of nonmetals include the following: Solid, liquid, or gas (depends on element) Solids are dull, brittle, poor conductors Large negative electronegativity/form anions readily

51. Periodic Properties of the Elements © 2015 Pearson Education, Inc. Nonmetal Chemistry Substances containing only nonmetals are molecular compounds. Most nonmetal oxides are acidic.

52. Periodic Properties of the Elements © 2015 Pearson Education, Inc. Recap of a Comparison of the Properties of Metals and Nonmetals

53. Periodic Properties of the Elements © 2015 Pearson Education, Inc. Metalloids Metalloids have some characteristics of metals and some of nonmetals. Several metalloids are electrical semiconductors (computer chips).

54. Periodic Properties of the Elements © 2015 Pearson Education, Inc. Hwk: page 290 - 296 : 55, 57, 59, 62, 63, 66

55. Periodic Properties of the Elements © 2015 Pearson Education, Inc. LESSON 7 7-7: Trends for Group 1A, Group 2A and Group 3A Metals

56. Periodic Properties of the Elements © 2015 Pearson Education, Inc. Group Trends Elements in a group have similar properties. Trends also exist within groups. Groups Compared:  Group 1A: The Alkali Metals  Group 2A: The Alkaline Earth Metals  Group 6A: The Oxygen Group  Group 7A: The Halogens  Group 8A: The Noble Gases

57. Periodic Properties of the Elements © 2015 Pearson Education, Inc. Alkali Metals Alkali metals are soft, metallic solids. They are found only in compounds in nature, not in their elemental forms. Typical metallic properties (luster, conductivity) are seen in them.

58. Periodic Properties of the Elements © 2015 Pearson Education, Inc. Alkali Metal Properties They have low densities and melting points. They also have low ionization energies.

59. Periodic Properties of the Elements © 2015 Pearson Education, Inc. Alkali Metal Chemistry Their reactions with water are famously exothermic.

60. Periodic Properties of the Elements © 2015 Pearson Education, Inc. Differences in Alkali Metal Chemistry Lithium reacts with oxygen to make an oxide: 4 Li + O 2  2 Li 2 O Sodium reacts with oxygen to form a peroxide: 2 Na + O 2  Na 2 O 2 K, Rb, and Cs also form superoxides: M + O 2  MO 2

61. Periodic Properties of the Elements © 2015 Pearson Education, Inc. Flame Tests Qualitative tests for alkali metals include their characteristic colors in flames.

62. Periodic Properties of the Elements © 2015 Pearson Education, Inc. Group 1A Elements (ns 1, n  2) M M +1 + 1e - 2M (s) + 2H 2 O (l) 2MOH (aq) + H 2(g) 2M (s) + O 2(g) M 2 O (s) Increasing reactivity M = Li, Na, K, Rb, Cs M = Na, K, Rb, Cs2M (s) + O 2(g) M 2 O 2(s)

63. Periodic Properties of the Elements © 2015 Pearson Education, Inc. Alkaline Earth Metals—Compare to Alkali Metals Alkaline earth metals have higher densities and melting points than alkali metals. Their ionization energies are low, but not as low as those of alkali metals.

64. Periodic Properties of the Elements © 2015 Pearson Education, Inc. Alkaline Earth Metals Beryllium does not react with water, and magnesium reacts only with steam, but the other alkaline earth metals react readily with water. Reactivity tends to increase as you go down the group.

65. Periodic Properties of the Elements © 2015 Pearson Education, Inc. Group 2A Elements (ns 2, n  2) M M +2 + 2e - Be (s) + 2H 2 O (l) No Reaction Increasing reactivity Mg (s) + 2H 2 O (g) Mg(OH) 2(aq) + H 2(g) M (s) + 2H 2 O (l) M(OH) 2(aq) + H 2(g) M = Ca, Sr, or Ba 2M (s) + O 2(g) 2MO (s) M = Be, Mg (high T) Ca, Sr, or Ba (room T)

66. Periodic Properties of the Elements © 2015 Pearson Education, Inc. Group 3A Elements (ns 2 np 1, n  2) 4Al (s) + 3O 2(g) 2Al 2 O 3(s) 2Al (s) + 6H + (aq) 2Al 3+ (aq) + 3H 2(g) Ga +, Ga 3+ In +, In 3+ Tl +, Tl 3+

67. Periodic Properties of the Elements © 2015 Pearson Education, Inc. Group 4A Elements (ns 2 np 2, n  2) C is a nonmetal Si, Ge are metalloids Sn, Pb are metals + 4 oxidation state more stable than +2 + 4 ox.state slightly more stable than +2 + 2 ox. state more stable than +4

68. Periodic Properties of the Elements © 2015 Pearson Education, Inc. LESSON 8 7-8: Trends for Selected Nonmetals

69. Periodic Properties of the Elements © 2015 Pearson Education, Inc. Hydrogen (1s 1, n = 1) An elemental “misfit”: no place in Periodic Table totally suitable for it……Could be in a class by itself!! Can form:H +, hydrated in aqueous soln. (H 3 O +, hydronium ion) H+H+ O O O O H H H H H HH H H9O4+H9O4+ Resembles Group 1A Metals

70. Periodic Properties of the Elements © 2015 Pearson Education, Inc. Group 5A Elements (ns 2 np 3, n  2) N P As Sb Bi Nitrogen: Nonmetal, N 2, forms N 3-, forms a number of oxides (NO, N 2 O, NO 2,N 2 O 4, N 2 O 5 ) N 2 O 5 (s) + H 2 O (l)  2 HNO 3 (aq) acid rain component Phosphorus: Nonmetal, P 4, forms P 3-, forms two main oxides, P 4 O 6, P 4 O 10 ) P 4 O 10 (s) + 6 H 2 O (l)  4 H 3 PO 4 (aq) acid rain component Arsenic: Metalloid, extensive 3-D structure Antimony: Metalloid, extensive 3-D structure Bismuth: Metal, less reactive than those in preceding groups

71. Periodic Properties of the Elements © 2015 Pearson Education, Inc. Group 6A Elements (ns 2 np 4, n  2) O S Se Te Po Oxygen: Nonmetal, O 2, forms O 2-, found in many ionic compounds Sulfur: Nonmetal, S 8, forms S 2-, found in ionic compounds & forms SO 2, SO 3, H 2 S SO 3 (g) + H 2 O (l)  H 2 SO 4 (aq) acid rain component Polonium: Metalloid, radioactive, Very difficult to study in lab Selenium: Nonmetal, Se 8, forms Se 2- Tellurium: Metalloid, forms Te 2-, More extensive 3-D structure

72. Periodic Properties of the Elements © 2015 Pearson Education, Inc. Group 6A—Increasing in Metallic Character down the Group Oxygen, sulfur, and selenium are nonmetals. Tellurium is a metalloid. The radioactive polonium is a metal.

73. Periodic Properties of the Elements © 2015 Pearson Education, Inc. Group 7A—Halogens The halogens are typical nonmetals. They have highly negative electron affinities, so they exist as anions in nature. They react directly with metals to form metal halides.

74. Periodic Properties of the Elements © 2015 Pearson Education, Inc. Group 7A Elements (ns 2 np 5, n  2) X + 1e - X - 1 X 2(g) + H 2(g) 2HX (g) Increasing reactivity

75. Periodic Properties of the Elements © 2015 Pearson Education, Inc. Group 8A—Noble Gases The noble gases have very large ionization energies. Their electron affinities are positive (can’t form stable anions). Therefore, they are relatively unreactive. They are found as monatomic gases.

76. Periodic Properties of the Elements © 2015 Pearson Education, Inc. Group 8A Elements (ns 2 np 6, n  2) He, Ne, Ar, Kr, Xe, Rn Completely filled outer ns & np subshells GREAT STABILITY “INERT GASES” 1s 2 Neil Bartlett (U.K.): Xe (g) + PtF 6 (g)  XePtF 6 (s) KrF 2 ; XePtF 6 : no commercial applications not involved in biological processes No known compounds of He, Ne, Ar

77. Periodic Properties of the Elements © 2015 Pearson Education, Inc. Hwk: page 290 - 296 : 67, 69, 75, 78

78. Periodic Properties of the Elements © 2015 Pearson Education, Inc. Review Questions Chapter 7

79. © 2015 Pearson Education, Inc. The first Periodic Table was created by a.Amadeo Avogadro. b.Dmitri Mendeleev. c.Henry Moseley. d.Ernest Rutherford.

80. © 2015 Pearson Education, Inc. The first Periodic Table was created by a.Amadeo Avogadro. b.Dmitri Mendeleev. c.Henry Moseley. d.Ernest Rutherford.

81. © 2015 Pearson Education, Inc. The effective nuclear charge felt by an atom’s valence electrons (X) going from left to right and (Y) going down a column on the periodic table. a.X = increases Y = increases b.X = increases Y = decreases c.X = decreases Y = increases d.X = decreases Y = decreases

82. © 2015 Pearson Education, Inc. The effective nuclear charge felt by an atom’s valence electrons (X) going from left to right and (Y) going down a column on the periodic table. a.X = increases Y = increases b.X = increases Y = decreases c.X = decreases Y = increases d.X = decreases Y = decreases

83. © 2015 Pearson Education, Inc. True or False: The large number of valence electrons in a chlorine atom greatly reduces the effective nuclear charge of the atom. a.True b.False

84. © 2015 Pearson Education, Inc. True or False: The large number of valence electrons in a chlorine atom greatly reduces the effective nuclear charge of the atom. a.True b.False

85. © 2015 Pearson Education, Inc. The atom with the smallest atomic radius is a.Ca. b.Cr. c.Co. d.Br.

86. © 2015 Pearson Education, Inc. The atom with the smallest atomic radius is a.Ca. b.Cr. c.Co. d.Br.

87. © 2015 Pearson Education, Inc. The correct order of increasing atomic radius (smallest  largest) is a.Na < Mg < K < Rb. b.Mg < Na < K < Rb. c.Rb < K < Na < Mg. d.Rb < K < Mg < Na.

88. © 2015 Pearson Education, Inc. The correct order of increasing atomic radius (smallest  largest) is a.Na < Mg < K < Rb. b.Mg < Na < K < Rb. c.Rb < K < Na < Mg. d.Rb < K < Mg < Na.

89. © 2015 Pearson Education, Inc. The shortest distance between the nuclei of two identical atoms when they collide is called the ___ radius. a.anionic b.cationic c.effective d.van der Waals

90. © 2015 Pearson Education, Inc. The shortest distance between the nuclei of two identical atoms when they collide is called the ___ radius. a.anionic b.cationic c.effective d.van der Waals

91. © 2015 Pearson Education, Inc. The statements below refer to ionic radii. Which statement is FALSE? a.Br 1– is larger than Cl 1–. b.Se 2– is larger than Br 1–. c.K 1+ is larger than Ca 2+. d.Na 1+ is larger than K 1+.

92. © 2015 Pearson Education, Inc. The statements below refer to ionic radii. Which statement is FALSE? a.Br 1– is larger than Cl 1–. b.Se 2– is larger than Br 1–. c.K 1+ is larger than Ca 2+. d.Na 1+ is larger than K 1+.

93. © 2015 Pearson Education, Inc. Two ions are isoelectronic if they have the same a.charge. b.number of protons. c.number of electrons. d.number of neutrons.

94. © 2015 Pearson Education, Inc. Two ions are isoelectronic if they have the same a.charge. b.number of protons. c.number of electrons. d.number of neutrons.

95. © 2015 Pearson Education, Inc. Which set represents an isoelectronic series? a.Ne, Ar, Kr, Xe b.Al, Si; Ge, As; Sb, Te c.Se 2−, Br −, Rb +, Sr 2+ d.Cu 2+, Ag +, Au

96. © 2015 Pearson Education, Inc. Which set represents an isoelectronic series? a.Ne, Ar, Kr, Xe b.Al, Si; Ge, As; Sb, Te c.Se 2−, Br −, Rb +, Sr 2+ d.Cu 2+, Ag +, Au

97. © 2015 Pearson Education, Inc. When a main-group metal ion loses an electron to form a cation, the ionic radius is ___ the atomic radius. a.greater than b.less than c.the same as d.impossible to predict in relation to

98. © 2015 Pearson Education, Inc. When a main-group metal ion loses an electron to form a cation, the ionic radius is ___ the atomic radius. a.greater than b.less than c.the same as d.impossible to predict in relation to

99. © 2015 Pearson Education, Inc. The minimum energy needed to remove an electron from an atom in its ground state is called the atom’s a.potential energy. b.activation energy. c.electron affinity. d.ionization energy.

100. © 2015 Pearson Education, Inc. The minimum energy needed to remove an electron from an atom in its ground state is called the atom’s a.potential energy. b.activation energy. c.electron affinity. d.ionization energy.

101. © 2015 Pearson Education, Inc. The energy change that occurs when an electron is added to an atom is called the atom’s a.potential energy. b.activation energy. c.electron affinity. d.ionization energy.

102. © 2015 Pearson Education, Inc. The energy change that occurs when an electron is added to an atom is called the atom’s a.potential energy. b.activation energy. c.electron affinity. d.ionization energy.

103. © 2015 Pearson Education, Inc. The correct order of increasing first ionization energy (smallest  largest) is a.Na < Ca < Al < Sn. b.Na < Al < Ca < Sn. c.Na < Al < Sn < Ca. d.Ca < Na < Sn < Al.

104. © 2015 Pearson Education, Inc. The correct order of increasing first ionization energy (smallest  largest) is a.Na < Ca < Al < Sn. b.Na < Al < Ca < Sn. c.Na < Al < Sn < Ca. d.Ca < Na < Sn < Al.

105. © 2015 Pearson Education, Inc. The atom with successive ionization energies of 578, 1817, 2745, and 11,577 kJ/mol is a.Al. b.Na. c.Mg. d.P.

106. © 2015 Pearson Education, Inc. The atom with successive ionization energies of 578, 1817, 2745, and 11,577 kJ/mol is a.Al. b.Na. c.Mg. d.P.

107. © 2015 Pearson Education, Inc. The correct order of increasing electron affinity (most negative  least negative) is a.O < Cl < B < C. b.O < Cl < C < B. c.Cl < O < C < B. d.Cl < O < B < C.

108. © 2015 Pearson Education, Inc. The correct order of increasing electron affinity (most negative  least negative) is a.O < Cl < B < C. b.O < Cl < C < B. c.Cl < O < C < B. d.Cl < O < B < C.

109. © 2015 Pearson Education, Inc. Most metal oxides form _______ solutions when dissolved in water. a.acidic b.basic c.neutral d.amphoteric

110. © 2015 Pearson Education, Inc. Most metal oxides form _______ solutions when dissolved in water. a.acidic b.basic c.neutral d.amphoteric

111. © 2015 Pearson Education, Inc. Most nonmetal oxides form _______ solutions when dissolved in water. a.acidic b.basic c.neutral d.amphoteric

112. © 2015 Pearson Education, Inc. Most nonmetal oxides form _______ solutions when dissolved in water. a.acidic b.basic c.neutral d.amphoteric

113. © 2015 Pearson Education, Inc. The metalloid with the least metallic character is a.As. b.B. c.Ge. d.Sb. e.Si.

114. © 2015 Pearson Education, Inc. The metalloid with the least metallic character is a.As. b.B. c.Ge. d.Sb. e.Si.

115. © 2015 Pearson Education, Inc. A soft gray solid reacts with water to form a flammable gas and a basic solution. The solid is most likely to be a a.noble gas. b.halogen. c.group IIA metal. d.transition metal.

116. © 2015 Pearson Education, Inc. A soft gray solid reacts with water to form a flammable gas and a basic solution. The solid is most likely to be a a.noble gas. b.halogen. c.group IIA metal. d.transition metal.

117. © 2015 Pearson Education, Inc. Ozone is an allotrope of which element? a.hydrogen b.oxygen c.sulfur d.chlorine

118. © 2015 Pearson Education, Inc. Ozone is an allotrope of which element? a.hydrogen b.oxygen c.sulfur d.chlorine

119. © 2015 Pearson Education, Inc. Unknown solid X turns a Bunsen burner flame green and produces a purple color on reaction with NaOCl. X is a.BaI 2. b.BaBr 2. c.SrI 2. d.SrBr 2.

120. © 2015 Pearson Education, Inc. Unknown solid X turns a Bunsen burner flame green and produces a purple color on reaction with NaOCl. X is a.BaI 2. b.BaBr 2. c.SrI 2. d.SrBr 2.

121. © 2015 Pearson Education, Inc. The noble gases a.are monatomic. b.have filled s and p subshells. c.are generally unreactive. d.All of the above.

122. © 2015 Pearson Education, Inc. The noble gases a.are monatomic. b.have filled s and p subshells. c.are generally unreactive. d.All of the above.