1. Warm Up
For the following molecules, Draw the Lewis Dot Structures, Predict the shape, Tell if the bonds are polar or nonpolar, and tell if the molecule itself is polar or nonpolar:
H2S O2
CCl4

2. Warm-up
Predict the shape and polarity of the following covalent molecules
OF2 H2
CH4
PCl3

3. Properties of Bonds
Bonding, Day Five

4. Strength of Bonds Non-polar bonds are the weakest Then come polar
And the strongest bonds are ionic
Bond strength is measured by boiling points and melting points
the stronger the bond, the higher the melting point and boiling point.

5. Properties of Ionic Compounds
Ionic bonds are the strongest!!
Composed of positive and negative ions
Form between a metal and a non-metal or a metal and a polyatomic ion
Solids at room temperature
When bonded, they are arranged very neatly – become crystals
High melting points and boiling points
Brittle
Conduct electricity when dissolved in water

6. Properties of Covalent Compounds
Smallest unit is a molecule
May be solid, liquid, or gas
Low melting and boiling points
Covalent solids are softer than ionic solids
Do not conduct electricity

7. Comparing within Covalent
Polar Covalent
Non-Polar Covalent
Dissolve in water
Stronger bonds (but not as strong as ionic)
Higher melting and boiling points
Exist as solids or liquids at room temperature
Ex: H2O, sugar
Do not dissolve in water
Very weak bonds
Low melting points and low boiling points
Exist as gases at room temperature
Ex: O2, H2

8. Properties of Metallic Compounds
Shiny
Malleable
Ductile
Crystalline
Solid at room temperature (except for Hg)
Melting points vary widely
Good conductors of heat and electricity
Do not dissolve in water

9. Type of Molecule Dissolve in Water? Conduct Electricity?
Metallic No
Yes
Ionic
Polar Covalent
Non-Polar Covalent

10. Na2S
CBr4
SO3
CaI2
PCl3 N2