1. Unit 1: Matter Bonding
Mr. Le
Fall 2018

2. Why bond!? Atoms are usually unhappy and crazy!
They need to bond to calm down and become stable

3. Why bond!?
To become stable, atoms will bond with other atoms, so that both atoms will:
Have 8 valence electrons or
Have a full outermost energy level

4. Valence Electrons
Valence Electrons: electrons on the last energy level.
Atoms can not have more than 8 valence electrons.

5. Energy Levels
Each energy level can only hold a specific number of electrons until it is “full”.
Energy level 1 = 2 valence electrons
Energy level 2 = 8 valence electrons
Energy level 3 = 18 valence electrons
Energy level 4 = 32 valence electrons
Use 2n2 to predict how many can fit on each energy level

6. What patterns do you see between your diagram of the atom and the atom’s location on the periodic table?

7. Unit 1: Matter Molecules vs Compounds
Mr. Le
Fall 2018

8. Molecules Molecule: particles that form when at least 2 atoms bond.
If you have at least 2 atoms bonded, you have a molecule.
These can be the same atoms bonded together or different atoms bonded together.

9. Compounds
Compounds: particles that form when two or more different elements bond.
You need to have at least 2 different atoms bonded to have a compound.
There has to be different atoms bonded together.

10. Compounds
Compounds are usually different from the elements that form them.
Sodium + Chlorine = Salt (Sodium Chloride)

11. Remember!!!
All compounds can be molecules, but not every molecule can be a compound.
For a substance to be a molecule, it needs to have at least 2 atoms bonded.
For a substance to be a compound, it needs to have at least 2 different atoms bonded.

12. Chemical Bonds
During bonding, atoms will either share their valence electrons or transfer their valence electrons

13. Ionic Bonding
Ionic bond: a chemical bond that forms when atoms transfer electrons.
An atom loses an electron, while another atom gains an electron.
As a result, the atom became an ion.

14. Ion Ion: a charged atom due to losing or gaining an electron. Example:
Fe+2, C-1, Na+1
If an atom loses an electron, what charge does it have? What if the atom gains an electron?

15. Covalent Bonds
Covalent Bonds: a chemical bond that forms when atoms share electrons.
As a result, the atoms form a neutral particle called a molecule.

16. Unit 1: Matter Chemical Formula
Mr. Le
Fall 2018

17. Chemical Formula
Chemical Formula: A combination of atomic symbols and numbers use to represent atoms that bonded.

18. Reading Chemical Formulas
Chemical Formula for Water is H2O
The atomic symbols tells you the names of the elements.
The small number behind an element tells you how many atoms it has.
If there are no number behind an element, it means one.

19. Reading Chemical Formulas
2H2O
If there is a coefficient in front of the formula, you multiply the coefficient with all the elements in the formula. Similar to the distributive property in math.
(Al2O3)2
If there is a subscript after a parenthesis, you multiply the subscript with all the elements in the parenthesis. Similar to the distributive property in math.