Chapter 2 The Material World Molecules Chapter 2 The Material World

Forming Ionic Compounds (Simple)

What are ionic compounds? Ionic compounds are compounds formed between a metal and a non-metal Metals lose electrons Non-metals gain electrons 2+ 2- Mg S

NaCl Na Cl Na Cl - + Examples: Ionic Bonds Draw the Lewis dot diagram to show the bond between sodium and chlorine. Na Cl NaCl - + Na Cl

Li2O Li O Li Li O + Examples: Ionic Bonds 2- Draw the Lewis dot diagram to show the bond between Lithium and Oxygen. Li O Li Li2O 2- + Li O

Mg N N N Mg3N2 Mg Mg Mg 2+ Examples: Ionic Bonds 3- 3. Draw the Lewis dot diagram to show the bond between magnesium and nitrogen. N Mg Mg Mg N Mg3N2 2+ 3- Mg N

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

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

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

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

Examples: Al+3 S-2 Al2S3

Ca+2 O-2 Ca2O2 Ca1O1