1. Ionic Bonding
Chapter 5

2. Bonding Ch.5 ionic bonding Ch.6 covalent bonding What is a bond?
What is bonding?

3. Learning Objective
Students will learn how to predict the type of ion that a given element forms from its position on the periodic table.
Youtube: What are Ions | The Chemistry Journey | The Fuse School

4. 5.1 Simple ions
How much an element reacts depends on it’s valence electron configuration
The noble gases show almost no chemical reactivity.
Why?
Because they have a full valence shell of electrons

5. 5.1 Simple ions
Octet rule
‘Atomsreactsothattheycanachievethesameelectronconfigurationsasthenoblegases.’
‘Atoms react so that they can achieve the same electron configurations as the noble gases.’
Exception = ?

6. Scratch paper Write the electron configuration of POTASSIUM
Write the electron configuration of CHLORINE
How many valence electrons do each of these elements have?

7. 5.1 Simple ions: metals Example: Potassium (K)
1s22s22p63s23p64s1
Potassium wants to lose it’s one valence electron to achieve the same valence electron configuration as Ar 
1s22s22p63s23p6
K  K+ + e

8. 5.1 Simple ions: metals After giving up one electron….
potassium still has 19 protons…..
but only 18 electrons.
= +1
Because the numbers are not the same, there is an overall electrical charge
= ION
K  K+ + e

9. 5.1 KWS: Cation CATions have a positive charge.
“Mr Turner feels positive about cats.”
“Cats have paws.”
Metals lose electrons to form cations.
“Metals go Meow”

10. 5.1 Simple ions: nonmetals
Chlorine is reactive because it has seven valence electrons.
1s22s22p63s23p5
If chlorine gains one electron it has the same electron configuration has a noble gas
Cl atom + e-  Cl- ion
1s22s22p63s23p5  1s22s22p63s23p6

11. 5.1 Simple ions: nonmetals
How many total electrons does a chlorine ion have?
ANS = 18
How many protons does Chlorine ion have?
ANS = 17
= -1
Therefore the chlorine ion has a -1 charge.

12. 5.1 KWS: Anion Memory clue “An aNion has a Negative charge.”
“Onions make us cry. We feel negatively about onions” (anions)

13. 5.1 Think about it…..
What is the name of the type of ion with a negative charge: cation or anion?
Give an example of an element that loses electrons to form an ion with a positive charge.

14. 5.1 Worksheet
‘Lewis Dot Structures of Atoms and Ions’

15. Practice
Write the electron configuration for:
Magnesium
Oxygen

16. 5.1 Simple ions What is the charge on the ion formed by Mg?
[Mg] = 1s22s22p63s2
Mg atom  Mg 2+ ion + 2e
Cation or anion?
= cation
How many electrons does Mg 2+ the ion have?
How many protons does the Mg 2+ ion have?

17. 5.1 Simple Ions What kind of ion is formed by oxygen? Anion!!
[O] = 1s22s22p4
O + 2e-  O2-
Anion!!
By gaining two electrons, oxygen is said to have “completed it’s octet”

19. 5.1 Simple Ions Misconception:
‘An atom and its ion have the same chemical properties.’ WRONG!!!!
e.g. potassium atom vs potassium ion
An atom and its ion have different chemical properties.
Start 11/13

20. 5.1 Simple Ions Misconception:
When an atom loses/gains electrons to form an ion, it achieves an electron configuration identical to a noble gas.
That does not mean it becomes a noble gas!
Ar vs Cl-

21. 5.2 Ionic Compounds Learning Target:
What happens when cations and anions combine together?
‘What are Ionic Bonds? | The Chemistry Journey | The Fuse School”

22. 5.2 Ionic Bonds When sodium and chlorine react…..
sodium gives it’s valence electron to chlorine.
Both elements ‘complete their octet’.
Sodium + Chlorine  Sodium Chloride (NaCl)
Element + Element  Compound
Teacher Notes:
VId: Reaction of Sodium and Chlorine
Lewis structure

23. 5.2 Ionic Bonds Metal + Nonmetal  Salt
In chemistry, a salt is not just sodium chloride,
Salt = the scientific name given to many different ionic compounds
Sodium + Fluorine  NaF (a salt)

24. Ionic compounds

25. 5.2 Ionic Bonds Electrostatic attraction: Opposites attract!
What is the force that holds a salt together?
Electrostatic attraction:
Opposites attract!
The force of attraction between a positive charge and a negative charge.

26. 5.2 Crystal lattice

27. 5.2 Ionic Compounds Learning Target:
What are the properties of ionic compounds?

28. Standard
c. Analyze and interpret provided data about bulk properties of various substances to support claims about the relative strength of the interactions among particles in the substance. Youtube: Ionic Bonding (Mexus)

29. 5.2 Ionic Bonding crystal lattice:
Salt crystals are made of repeating units of anions and cations

30. 5.2 Ionic Bonding
Ionic bonds are very strong

31. 5.2 Ionic Bonding
Attractive forces involve more than a single cation and anion.
Six Na+ ions surround each Cl ion and
Six Cl- ions surround each Na+ ion.
Youtube:
Sodium Chloride Crystal lattice
End per 1,2,3,4,6

32. 5.2 X-ray crystallography

33. Born-Haber Cycle p.169

34. Notes: Bond making/breaking
Breaking chemical bonds requires (releases/requires) energy
Forming chemical bonds releases (releases/requires) energy

35. Standard
d. Develop a representation to show that energy is required to separate the atoms in a molecule and that energy is released when atoms at a distance come together to form molecules that are more stable.

36. 5.2 Conductivity p.172
An ionic compound conducts electricity when dissolved in water
‘Electrolyte’
Demo: conductivity meter
Youtube: Gatorade Hydration Institute :

37. 5.2 Ionic Bonding
Notes:
“To conduct an electric current, a substance must satisfy two conditions:
it must contain charged particles
those particles must be free to move”
Teacher Notes:
conductivity meter

38. 5.3 Names & Formulas of ionic compounds
Objectives
When given the formula of a compound we can write the name
E.g. NaCl = Sodium Chloride
When given the name of a compound we can write the formula
E.g. Sodium Chloride = NaCl

39. 5.3 Names & Formulas of ionic compounds
Formula  Name
The name of an ionic compound is made up of just two words:
First, name of the cation
Cations have the same names as the elements.
For example, K+ = potassium ion.
Second, the name of the anion
For anions, the name ends in -ide.
For example, chlorine becomes chloride
For example, KCl is potassium chloride

40. 5.3 Names & Formulas of ionic compounds
Formula  Name
For anions, the name ending changes to in -ide.
F- = fluoride
Cl = chloride
Br- = bromide
I- = iodide
O2- = oxide

41. 5.3 Names & Formulas of ionic compounds
Formula  Name
The name of a binary ionic compound is made up of just two words: the name of the cation followed by the name of the anion.
NaCl sodium chloride
K2O potassium oxide
Al2S3 aluminum sulfide
Practice:
Concept Review p. 7 #16-31
(skip # 24,28, 30,31)

42. 5.3 Names & Formulas of ionic compounds
Exception
Many transition elements form more than one possible ion
For example, the names of the two copper ions are:
Cu+ Cu2+
Teacher notes: Common Ions handout

43. 5.3 Transition metal ions p.163
Example:
Cu+ = copper (I)
Cu2+ = copper (II)

44. 5.3 Transition metal ions p.163
If there is more than one possible ion…..
roman numerals are used to indicate the charge.

45. 5.3 Names & Formulas of ionic compounds
Objectives
When given the formula of a compound we can write the name
E.g. NaCl = Sodium Chloride
When given the name of a compound we can write the formula
E.g. Sodium Chloride = NaCl
Worksheet: Chemical Formulas and Names of Ionic Compounds

46. 5.2 Ionic Bonding Ionic Compounds Do Not Consist of Molecules
Water is a molecular compound, so individual water molecules are each made of two hydrogen atoms and one oxygen atom.
Youtube: How water dissolves salt

47. Crystal lattice
The formula of an ionic compound just tells us the ratio of ions in that compound e.g. NaCl = Na1Cl1 Na+:Cl- 1:1

48. 5.2 Ionic Bonding Ionic Compounds Do Not Consist of Molecules
There are no individual, separate molecules in an ionic compound.

49. 5.3 Names & Formulas of ionic compounds
Name  Formula
ionic compounds have no overall charge
The rule:
total positive charge (cations) + total negative charge (anions) = 0

50. 5.3 Names & Formulas of ionic compounds p.177
Try: magnesium chloride
Procedure:
Write the symbol and charges for the cation and the anion (remember sec 5.1)
Determine the ratio that the ions must combine in so that their charges cancel (Tip: look for the lowest common multiple)
Use subscripts to denote the ratio of cations to anions e.g. AxBy

51. 5.3 Names & Formulas of ionic compounds
Chapter 5
5.3 Names & Formulas of ionic compounds
Name  Formula
Guided Practice:
Sodium oxide
Calcium oxide
Aluminum oxide
Independent Practice:
Concept Review p. 6 # 9-15
Concept Review p. 7 # 24,28, 30,31
Finished?
Try: p.180 #6 b,c,d #7 a,b,c
‘crossing technique’

52. Aluminum Oxide

53. 5.3 Names & Formulas of ionic compounds
Example: aluminum oxide
What is the charge on the ion formed by aluminum?
What is the charge on the ion formed by oxygen?

54. 5.3 Names & Formulas of ionic compounds
The Al3+ ion has three positive charges, and the O2− ion has two negative charges.
The cations and anions must be combined in such a way that there are the same number of negative charges and positive charges.
What ratio will the aluminum ion and the oxygen ion combine in?

55. 5.3 Names & Formulas of ionic compounds
Two Al3+ cations are needed for every three O2 anions.
That way, there are six positive charges and six negative charges.
Subscripts are used to denote ion ratios.
Therefore, the formula for aluminum oxide is Al2O3.

56. 5.3 Names & Formulas of ionic compounds
POLYATOMIC ION
A polyatomic ion is a charged group of several bonded atoms with an overall charge.
Examples:
See Table 2 p. 178
See Ions Sheet
Names of polyatomic anions often have the ending –ate or -ite

57. 5.3 Polyatomic Ions Learning Targets:
Be able to identify a polyatomic ion
e.g. cyanide = CN-
Be able to read a chemical formula containing a polyatomic ion
e.g. Fe2(CrO4)3
Formula  Name
e.g. Fe2(CrO4)3 = iron (III) chromate
Name  Formula
e.g. potassium chromate = K2CrO4
Start per 3

58. 5.3 Polyatomic Ions Consider the polyatomic ion hydroxide, OH-
Hydroxide is made of one oxygen atom and one hydrogen atom, chemically attached together
It has a total of 9 protons and 10 electrons.
So the hydroxide ion has a 1- charge overall.

59. 5.3 Polyatomic Ions Sodium Hydroxide Chemical formula: NaOH Na+ : OH-
1:1

60. 5.3 Names & Formulas of ionic compounds
Ammonia molecule
See Ions Sheet handout
Youtube: What is a polyatomic ion?
Ammonium ion

61. 5.3 Names & Formulas of ionic compounds
Consider the polyatomic ion ammonium, NH4+
Ammonium is made of one nitrogen and four hydrogen atoms.
They have a total of 11 protons but only 10 electrons.
So the ammonium ion has a 1+ charge overall.
This charge is not found on any one atom. Instead, it is spread across this group of bonded atoms.

62. 5.3 Think about it….. Polyatomic Ions
How many atoms are there in a nitrate ion? NO3-
How many atoms are there in a nitrite ion? NO2-
ANS:
Nitrate = four atoms
Nitrite = three atoms

63. 5.3 Polyatomic ions Consider Rb3PO4 What is the name of the Rb3PO4?
How many rubidium ions are in one unit of Rb3PO4?
How many phosphorous atoms are in one unit of Rb3PO4?
How many oxygen atoms are in one unit of Rb3PO4?
What is the total number of atoms in one unit of Rb3PO4?

64. 5.3 Polyatomics Name  Formula
e.g. what is the formula of sodium sulfate?
Use the same procedure as for regular monatomic ions
Write the charges on the cation and anion
Balance the charges (crossing technique)
Simplify and remove the 1s (if necessary)

65. 5.3 Polyatomics Name  Formula
e.g. what is the formula of calcium carbonate?
Use the same procedure as for regular monatomic ions
Write the charges on the cation and anion
Balance the charges (crossing technique)
Simplify and remove the 1s (if necessary)

66. 5.3 Names & Formulas of ionic compounds
Sample Problem
What is the formula for iron(III) chromate?

67. 5.3 Names & Formulas of ionic compounds
Determine the formula and charge for the iron(III) cation.
Fe3+
Determine the formula and charge for the chromate polyatomic ion.

68. 5.3 Names & Formulas of ionic compounds
To balance the charges, find the lowest common multiple of the ions’ charges
for 2 and 3, it is 6.
For 6 positive charges, you need 2 Fe3+ ions.
2  3 = 6+

69. 5.3 Names & Formulas of ionic compounds
For 6 negative charges, you need ions.
The formula must show 2 Fe3+ ions and ions.
The formula for iron(III) chromate is Fe2(CrO4)3

70. 5.3 Polyatomic Ions Fe2(CrO4)3 How many atoms in one formula unit?
ANS =
2 Fe3+
3 Cr
12 O
= 17 atoms in one formula unit