1. When non-metals combine
Molecular Compounds
When non-metals combine

2. Non-Metal Elements
Appear on the right side of the periodic table (except for Hydrogen)
Need to take electrons
Examples: Halogens (F, Cl, Br)

3. When they get together things don’t work out as well as when metals meet non-metals because they both want electrons
Let’s say that two Fluorine atoms bump into each other

4. Neither one is happy. They both need an electron
What can they do when they both need an electron

5. Finally, they figure something out
And they make a deal
They agree to each share one of their electrons

6. Now they’re both happy
When two atoms share electrons it is called a covalent bond.
And they form something called a molecule.
This molecule has the formula F2

7. Here’s another example: Carbon and oxygen
Let’s not worry about naming them right now. That can be a little complicated so we’ll save it for grade 10
Here’s another example: Carbon and oxygen
Oxygen needs two electrons
Carbon needs four

8. So oxygen gets a friend
Each one shares two electrons with the carbon atom
And the carbon atom shares two electrons with each oxygen

9. And they look something like this
And everyone’s happy!
And the formula is CO2

10. When you show what the model looks like it is called a structural formula
When you make one, you draw a line to show two atoms sharing an electron
So F2 looks like this F-F
And CO2 looks like this O=C=O

11. Practice
Give the formula for a molecule when each of the following elements combine
Hydrogen and Oxygen
Iodine and Iodine
Hydrogen and Chlorine
Hydrogen and Nitrogen
Nitrogen and Oxygen
Oxygen and Oxygen

12. More Practice! Now make the structural formula for each one
Hydrogen and Oxygen
Iodine and Iodine
Hydrogen and Chlorine
Hydrogen and Nitrogen
Nitrogen and Oxygen
Oxygen and Oxygen