1. Ionic Bonding

2. Ionic Bonding Involves the transfer of valence electrons
Attraction between a cation and an anion
Cation
Positively charged ion
Typically metals
But could be a polyatomic ion
Anion
Negatively charged ion
Typically nonmetals
But could be a polyatomic ion

3. Ionic Bonding

4. Ionic Bonding
The oppositely charged ions are attracted to each other by a force called an ionic bond

5. Properties of Ionic Compound
Most ionic compounds:
Have high melting points
Are hard and brittle
Are soluble in water
Form electrolytes (conduct electricity) when dissolved in water

6. Crystal Lattice Structure
Ionic compounds form crystal lattices
This explains why they have high melting points and are hard but brittle
Na+
Cl-

7. Ionic Compounds in Water
When ionic compounds dissolve, they separate into their ions
The free ions can now move and conduct electricity

8. Representing Ionic Compounds Lewis Diagrams
Formation of sodium chloride: Cl
· ·
Na+ [ ] Cl
· · Na +

9. Lewis Structures for Ionic CompoundsBa • O •• •• O Ba 2+ 2-
Ba and O
BaO Mg • Cl •• •• Cl Mg 2+ - 2
Mg and Cl
Binary ionic compounds.
Note the types of arrows used to move electrons – fishhooks for single e-.
Write the Lewis symbol for each atom Determine how many e- each atom must gain or lose.
Use multiples of one or both ions to balance the number of electrons.
MgCl2

10. Representing Ionic Compounds Criss-Cross Method
For monatomic ions:
Take the absolute value of the ionic charge for the cation and make it the subscript for the anion and vice versa.
Example: Al3+ and Cl-
The 3 becomes the subscript for the chloride ion and the 1 becomes understood for aluminum.
Forming aluminum chloride: AlCl3

11. Representing Ionic Compounds Criss-Cross Method
For polyatomic ions:
Additional step of including brackets around the polyatomic ion if it has a subscript other than one.
Example: Mg2+ and OH-
The 2 becomes the subscript for the hydroxide ion, but brackets are needed to indicate 2 of each the O and the H.
The 1 becomes the understood subscript for Mg.
Forming magnesium hydroxide: Mg(OH)2

12. Polyatomic Ions NICK the CAMEL ate a CLAM for SUPPER in PHOENIX
Underlined letter represents the symbol of the element.
The consonants represent the number of oxygen
The vowels represent the negative charge.
Eg. Underlined letter= N
Number of consanants= 3 represents oxygens
Number of vowels= 1 represents charge
NO3- Nitrate

13. Practice Problems
p. 68 #1,4
p. 71 #1-5
p. 73 #8-14
p. 74 #1-5