1. So, what makes a bond ionic?
1. Electrons are transferred
2. Usually involves a metal (+) and non-metal (-)
Opposite sides of the table
3. Products are called salts

2. Ionic compounds are tightly packed together to form ionic crystals=
Negatives
Positives + _ + _
Lattice fence
Strong attraction of positive to negative result in the formation of a crystal lattice

3. As a result, ionic compounds have a very high bond strength.

4. When determining the strength of a bond, scientist look at three things
Hardness
Melting Point
Boiling Point

5. Hard, Rigid, Brittle Crystalline Structure
Ionic compounds form hard crystalline structures
But the structure will break in a characteristic way if a force is applied. + _ + _

6. Hard, Rigid, Brittle Crystalline Structure
Ionic compounds form hard crystalline structures
But the structure will break in a characteristic way if a force is applied. + _ + _

7. Image from the website:
Salt - NaCl
Image from the website:

8. Melting and Boiling Points
The intermolecular forces between ions are strong and require more energy to break.
More Energy = Higher Temperatures
Therefore, ionic compounds have _______ melting and boiling points.
High

9. When ionic compounds are solid…
They are nonconductors of electricity
Why?
They are so tightly packed they can’t move. + _
Nothing

10. However, when they are in water (or melt)…
The ions separate or dissociate, then they can move and can carry electricity. + _

11. However, when they are in water (or melt)…
The ions separate or dissociate, then they can move and can carry electricity. _ _ + + _ _
ZAP!!! + + _ _ + +

12. A special name for ionic solutions
Electrolytes are ionic compounds that are dissolved in a medium.
The most common medium
Hint: When you hear Electrolyte, think electricity
- water

13. Conductivity in Action
Water – the medium
Sugar – Covalent Bonding
Table Salt – Ionic Bonding
Image from the website:

14. Ionic Bonds are exothermic
When made, they release energy
Energy, usually heat, exits (exo) the system
And it takes energy to break ionic bonds after they are made.
This energy is called the lattice energy.

15. Facts about Lattice Energies
The more negative the value, the harder it is to break.
This fact is related to:
Size of Ions
Charge of the ion

16. Size of Ions
Smaller ions have more negative values because their nuclei are closer together and they have more attraction to each other.
Therefore, it is harder to pull apart.

17. Charge of the Ion
Large positive or negative ions have a more negative lattice energy.
So they are harder to pull apart.

18. Homework
Page 175: 2, 3, 4, 6 and Page 184: