1. Ionic Bonding

2. Ionic Bonding
Ionic compounds are formed when one or more valence electrons are transferred from a metal atom to a non-metal atom.
Usually a metal cation and an non-metal anion.
The charge of each ion correlates to the number of electrons lost or gained.
The two oppositely charged ions are attracted to each other by a force called a ionic bond.

3. Ionic Bonding
The smallest amount of substance that has the composition given by its chemical formula is the formula unit.
Eg. NaCl is a 1:1 ratio, MgCl2 is a 1:2 ratio.

4. Ionic Properties / Structure
Ionic compounds are solids at standard temperature and pressure. In their solid form they form solid ionic crystals. These are more commonly known as salts

5. General properties
high MP, BP and hard. It takes a lot of energy to break the bonds between the ions.
Many are brittle
When ionic compounds are dissolved in water they dissociate into their ions.
Conduct electricity when dissolved in water
NaCl(s)  Na+(aq) + Cl-(aq)

6. How an Ionic Bond Forms:
Example- Li Li + F F -

7. How an Ionic Bond Forms:
Example 2 O Na Na Na O 2 Na

8. The Cross over rule
This rule allows you to figure out how many atoms you will need of each element for bonding to occur without the need to draw Bohr diagrams

9. Cross Over Rule
Step 1.
Write the symbols, with the metal first (the element with the positive charge)
Step 2.
Write the Ionic charge above each symbol to indicate the stable ion that each element forms.
Mg I
2+ 1-
Mg I

10. Cross Over Rule
Step 3. Draw an arrow from the metals charge to the non- metal and an arrow from the non-metal charge to the metal. (Cross over the arrows)
2+ 1-
Mg I

11. Cross Over Rule
Step 4.
Fill in the number of atoms from each element will have by following the arrows. If need be reduce to lowest terms (in other words, if they are the same number, you don’t write those numbers down because you could divide the whole molecule by that number which would = 1)
MgI2
(if the number crossed is a 1, the 1 is not shown)
Naming the compound
Cation-gets the name of the element—> in this case Magnesium
Anion-

12. Example 2- Try yourself
Ca O

13. Example 3- Try yourself
Zr O

14. Example 4- Try yourself
Al S

15. Example 5- Try yourself
Ni N