1. Ionic Compounds and Metals
Chemistry Matter and Change: Chapter 7

2. BIG IDEA
Atoms in ionic compounds are held together by chemical bonds formed by the attraction of oppositely charged ions.

3. 7.1 Ion Formation

4. 7.1 Main Idea
Ions are formed when atoms gain or lose valence electrons to achieve a stable octet electron configuration.

5. 7.1 Objectives Define a chemical bond.
Describe the formation of positive and negative ions
Relate ion formation to electron configuration.

6. Review Vocabulary & Concepts
Ion
Valence electron
Octet
Electron configuration
Lewis-dot diagrams
Electron affinity

7. New Vocabulary
Chemical bond
Ionic bond
Cation
Anion

8. Chemical Bond The force that holds two atoms together Three types
Ionic bonds *Chap 7
Metallic bonds *Chap 7
Covalent bonds *Chap 8

9. Valence Electrons and Chemical Bonds
Each valence electron is represented as a dot around the nuclear core of the element.

10. Valence Electrons and Chemical Bonds
The most stable electron configuration for an element is the nearest noble gas.
ns2np6
Octet
Ions gain or lose electrons to achieve noble gas configurations

11. Octet Rule
In forming compounds, atoms tend to achieve the electron configuration of a noble gas
ns2np6
Atoms of metals tend to lose their valence electrons leaving a complete octet in the next lowest energy level
Atoms of non-metals tend to gain electrons or to share electrons with another non metal to achieve a complete octet

12. Formation of Ions

13. Positive Ion Formation
Cation: a positively charged ion
Results when electrons are lost

14. Metal ions Group 1 loses 1 electron Group 2 loses 2 electrons
+1 charge
Group 2 loses 2 electrons
+2 charge
Group 13 loses 3 electrons
+3 charge
Groups 3-12 usually lose 2 electrons
Most have +2 charge (range from +1 to +3)

15. Negative Ion Formation
Anion: negatively charged ion
Formed when electrons are gained
Non-metals

16. Nonmetal Ions Group 15 gains 3 electrons Group 16 gains 2 electrons
3- charge
Group 16 gains 2 electrons
2- charge
Group 17 gains 1 electron
1- charge

17. Section Summary
A chemical bond is the force that holds two atoms together
Some atoms gain or lose electrons to gain a stable configuration; these are called ions
Most stable configurations end: ns2np6.

18. Sodium Electron loss or ionization of sodium atom
Na 1s22s22p63s1 → Na+ 1s22s22p6

19. The electron configuration of a sodium ion is the same as a neon atom

20. Chlorine
A gain of one electron gives chlorine an octet and converts a chlorine atom into a chloride ion.
It has the same electron configuration as argon 20

21. Gain of valence electrons21

22. Section 7.1 practice #1:
1. How many valence electrons does each of the following atoms have?
gallium
fluorine
selenium

23. Section 7.1 practice #2:
2. For each element below, state (i) the number of valence electrons in the atom, (ii) the electron dot structure, and (iii) the chemical symbol(s) for the most stable ion. Ba I K

24. Section 7.1 practice #3
3. Write the electron configuration for each of the following atoms and ions.
K atom
K ion
c. Na atom
d. Na ion
e. Phosphorous atom
f. Phosphide ion

25. Section 7.1 practice #4
4. How many electrons will each element gain or lose in forming an ion? State whether the resulting ion is a cation or an anion.
a. strontium (Sr)
b. tellurium (Te)
c. Bromine (Br)
d. aluminum (Al)
e. rubidium (Rb)
f. Phosphorus (P)

26. 7.2 Ionic Bonds and Ionic Compounds

27. 7.2 Main Idea
Oppositely charged ions attract each other forming electrically neutral ionic compounds.

28. 7.2 Objectives
Describe the formation of ionic bonds and the structure of ionic compounds
Generalize about the strength of ionic bonds based on the physical properties of ionic bonds
Categorize ionic bond formation as exothermic or endothermic

29. Review Vocabulary & Concepts
Compound
Chemical bond
Physical property
Chemical property
Electronegativity

30. New Vocabulary Ionic bond Ionic compound Crystal lattice
Binary compound
Electrolyte

31. Formation of an Ionic Bond
Electrons are exchanged between atoms
Increases stability of both
Ions are held together by the opposite charges

32. Definition of Ionic Bond
Bond formed between two elements with an electronegativity difference > 1.7
Crystallize as sharply defined particles

33. Video Another Video

34. Binary Ionic Compounds
Formed from a metal and a non-metal
Contain only two elements
Examples
NaCl
MgO
CaCl2
Fe2O3

35. Formation of Ionic Compounds
Net charge on all ions in a compound must be zero (0)!
More on this later!!!

36. Properties of Ionic Compounds
Crystal Lattice: Highly organized crystal of cations and anions
Anion
Cation

38. Properties of Ionic Compounds
Crystalline shape depends on the ions involved

39. Properties of Ionic Compounds
Physical properties
Very strong
Solid at normal temperatures
Very high melting point and boiling point
Many have brilliant colors due to transition metals
Hard, rigid
Brittle

40. Properties of Ionic Compounds
Conductivity (ability for electric charge to move through a substance
Solids have electrons locked in place
Non conductive
Aqueous solutions have easily moveable electrons
Electrolytes
Good conductors

41. Properties of Ionic Compounds
Dissolve in water
May have radically different properties than the elements that compose them
Polar Dissolution

42. Water and ionic bonds

43. Properties of Ionic Compounds
Formation of lattice is always exothermic.

44. Section Summary
Ionic compounds contain ionic bonds formed by the attraction of oppositely charged ions.
Ions in an ionic compound are arranged in a repeating pattern called a lattice.
Ionic compounds are electrolytes; they conduct electricity in liquid and aqueous states.

45. Can you…
Describe the formation of ionic bonds and the structure of ionic compounds
Generalize about the strength of ionic bonds based on the physical properties of ionic bonds
Categorize ionic bond formation as exothermic or endothermic

46. 7.3 Names and Formulas for Ionic Compounds

47. 7.3 Big Idea
In written names and formulas for ionic compounds, the cation appears first, followed by the anion.

48. 7.3 Objectives
Relate a formula unit of an ionic compound to its composition
Write formulas for ionic compounds and oxyanions.
Apply naming conventions to ionic compounds and oxyanions.

49. Review Vocabulary & Concepts
Anion
Cation
Metal
Non-metal

50. New Vocabulary Formula unit Monatomic ion Polyatomic ion
Oxidation number
Oxyanion

51. Describing Ionic Compounds
Formula unit- simplest way to indicate the composition of an ionic substance
NaCl
MgCl2
Cl-
Cl-
Mg2+

52. Monatomic Ions Ions in which only one element is present
Na+, Cl-, Mg2+, P3-

53. Oxidation number Fancy word for “charge” aka oxidation state
Transition metals may have multiple oxidation states
Must tell the oxidation state
Ex: Iron 2+ is Iron II; Iron 3+ is Iron III

54. Formulas for Binary Ionic Compounds
CxAy
C is cation
A is anion
x number of cations in one unit
y is number of anions in one unit

55. Rules for writing formula units
CxAy
Cation is always first
Anion is always second
Net oxidation MUST BE ZERO

56. Tried and True Method Write out each ion.
Place oxidation number under each ion
Cross multiply
Reduce to simplest form

57. Write out each ion.
Example 1:
Sodium and chlorine
Na Cl

58. Place oxidation number under each ion
Sodium and chlorine
Na Cl

59. Cross multiply
Sodium and chlorine
Na Cl
Na Cl

60. Reduce to simplest form
Remove any “1”s
NaCl
Reduce if needed
NaCl

61. Write out each ion.
Iron III and oxygen
Fe O

62. Place oxidation number under each ion
Example 2:
Iron III and oxygen
Fe O

63. Cross multiply
Iron III and oxygen
Fe O
Fe O

64. Reduce to simplest form
Fe2O3
Cannot be reduced

65. Write out each ion.
Example 3:
Magnesium and oxygen
Mg O

66. Place oxidation number under each ion
Magnesium and oxygen
Mg O
2+ 2-

67. Cross multiply
Magnesium and oxygen
Mg O
Mg O

68. Reduce to simplest form
Mg2O2
Both subscripts can be divided by 2 so the final formula is
MgO

69. Why did we specify some oxidation numbers, but not others?
Practice
Silver I and chlorine
Antimony (V) oxide
Aluminum sulfide
Magnesium and fluorine
Iron II and oxygen
Calcium and phosphorus
Why did we specify some oxidation numbers, but not others?

70. Rules for Naming Binary Ionic Compounds
State the name of the cation.
(If using a transition metal, you must state the oxidation number if there is more than one possibility.)
State the name of the anion, but change the ending to “ide.”

71. Practice NaCl MgO K2S Sodium chlorine chloride Magnesium oxide
Potassium sulfide

72. Tricky practice
Fe2O3
Iron is a transition metal so we need to figure out the charge before we can name the compound.
We know oxygen is always -2, so there is an overall charge of -6 from the oxygen
That means Iron must supply an overall charge of +6
This indicates that iron must have an oxidation number of +3 in this case

73. Tricky practice
Fe2O3
Iron III oxide
CuS
AgCl* (trick!)
H2O

74. Monatomic Ions vs polyatomic Ions
Monatomic ion: a one atom ion
Ex. Mg 2+
Polyatomic ion: ions made up of more than atom
Ex. PO4 3-

75. Oxyanions
Oxyanions- a polyatomic ion composed of an element, usually a nonmetal, bonded to one or more oxygen atoms.
The ion with the greater number of oxygen atoms ends in –ate.
The ion with the fewer number of oxygen atoms ends in –ite.
Ex. NO NO2-
Nitrate Nitrite

76. Take out a sheet of paper
Directions:
Draw 5 by 5 chart.
Write 5 metals ions in the left margin
Write 5 nonmetal ions on the top
Trade charts with the person next to you
Fill in the charts by writing the correct formulas for the ionic compounds formed in the square.
Hand the chart back to your partner when your done and check each others responses.
Once finished, raise your hand and ask Mrs. Chebib to come over and stamp your work for credit

77. Naming Polyatomic Ions
State the name of the cation.
(If using a transition metal, you must state the oxidation number if there is more than one possibility.)
Name the anion

78. Practice AgNO3 CaCO3 NH4Cl FeSO4 Silver nitrate Calcium carbonate
Ammonium chloride
FeSO4
Iron II sulfate

79. Writing formulas for ionic compounds with polyatomic ions
Write out each ion.
Place oxidation number under each ion
Cross multiply
Reduce to simplest form

80. Side note Oxyanions are any polyatomic anions that contain oxygen
Your book likes to sound fancy!

81. Writing formulas for ionic compounds with polyatomic ions
You may not, under any conditions, change the subscripts within the polyatomic ion when balancing the charge. You may only adjust the number of units of each polyatomic ion!!
Use parentheses to remind yourself that the units go together and cannot be changed.

82. Write out each ion.
Potassium permanganate
K (MnO4)

83. Place oxidation number under each ion
Potassium permanganate
K (MnO4)

84. Cross multiply
Potassium permanganate
K (MnO4)
K (MnO4)

85. Reduce to simplest form
Potassium permanganate is
K(MnO4)

86. Write out each ion.
Calcium hydroxide
Ca (OH)

87. Place oxidation number under each ion
Calcium hydroxide
Ca (OH)

88. Cross multiply
Calcium hydroxide
Ca (OH)
+2 -1
Ca(OH)2

89. Reduce to simplest form
Ca(OH)2

90. Write out each ion.
Ammonium phosphate
(NH4) (PO4)

91. Place oxidation number under each ion
Ammonium phosphate
(NH4) (PO4)

92. Cross multiply
Ammonium phosphate
(NH4) (PO4)
(NH4)3(PO4)

93. Reduce to simplest form
(NH4)3(PO4)

94. Practice
Sodium nitrite
Calcium sulfate
Aluminum hydroxide

95. Section Summary
A formula unit gives the ration of cations to anions in the ionic compound.
A monatomic ion is formed from one atom.
Roman numerals indicate the oxidation numbers of any element with more than one oxidation number.

96. Section Summary
Polyatomic ions consist of more than one atom and act as a single unit.
To indicate more than one polyatomic ion in a chemical formula, place parentheses around the polyatomic ion and use a subscript outside the parentheses.

97. Can you… Relate a formula unit of an ionic compound to its composition
Write formulas for ionic compounds and oxyanions.
Apply naming conventions to ionic compounds and oxyanions.

98. 7.4 Metallic Bonds and the Properties of Metals

99. 7.4 Main Idea
Metals form crystal lattices and can be modeled as cations surrounded by a “sea” of freely moving valence electrons.

100. 7.4 Describe a metallic bond
Relate the electron sea model the physical properties of metals
Define alloys and categorize them into two basic types.

101. Review Vocabulary & Concepts
Physical property
Metal
Malleable

102. New Vocabulary Electron sea model Delocalized electron Metallic bond
Alloy

103. Metallic Bonds Lattice structures with freely moving electrons
Electrons are not firmly attached to any one nucleus, but instead “visit” many nuclei

104. Metallic Bonds
Attraction of a metallic cation for delocalized electrons

105. The Electron Sea
Freely moving electrons are referred to as “delocalized” (lacking a location)
Video

106. + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + - - - - -

107. Properties of Metals Melting and Boiling points Vary greatly
Most are moderately high melting points and very high boiling points

108. Properties of Metals Malleability, ductility and durability
Nuclei move relatively free of each other due to the sea of electrons

109. Properties of Metals Thermal and electrical conductivity
Delocalized electrons quickly move heat from one part of the metal to other parts
Delocalized electrons can move in one direction and create a “current.”

110. Properties of Metals Hardness and strength
The number of delocalized electrons plays a role in the hardness of the metal
More delocalized electrons means a harder metal
Sometimes d level electrons are delocalized as well as the s resulting in very hard metals.

111. Metal Alloys Alloy- a mixture of elements that has metallic properties
Characteristics may differ from the “parent” metals
Include brass, bronze, 14-carat gold, stainless steel, etc.

112. Types of Metal Alloys Substitutional
Some of the atoms from one metal are replaced by atoms of the other metal
Ex: brass

113. Types of Metal Alloys Interstitial
Small holes in the lattice are filled by atoms of another element
Example: Steel

114. Section Summary
A metallic bond forms when metal cations attract freely moving, delocalized valence electrons.
The electron sea model explains the physical properties of metallic solids.
Metal alloys are formed when a metal is mixed with one or more other elements.

115. Can you… Describe a metallic bond
Relate the electron sea model the physical properties of metals
Define alloys and categorize them into two basic types.