1. Chapter 2 The Material World
Molecules
Chapter 2
The Material World

2. Forming Ionic Compounds (Simple)

3. Mg+2 Cross Over Method Mg 12p+ +12 10e- -10 +2 2 valance e-
Wants to lose 2 e- to achieve full octet
If Mg loses 2 e-  now has 12p+ and 10e-
Mg+2
12p+
10e-
+12
-10 +2

4. F-1 Cross Over Method F 9p+ +9 10e- -10 -1 7 valance e-
Wants to gain 1e- to achieve full octet
If F gains 1 e-  now has 9p+ and 10e-
F-1
9p+
10e- +9
-10 -1

5. Mg+2
F-1
Mg1F2
Do not have to show “1”

6. +2 F -1 Mg 1 2
Do not have to show “1”
MgF2

7. Examples:
Al+3
S-2
Al2S3

8. Ca+2
O-2
Ca2O2
Ca1O1

9. Naming Ionic Compounds

10. Naming Ionic Compounds
RULE: Metal Name + Non-Metal Name (modified ide ending)
Examples:
CaCl2  Calcium Chloride
MgO  Magnesium Oxide
Na2S  Sodium Sulfide
Ignore the subscripts!