1. Welcome Back! Grab…binders and handouts off the door
4/9 Do Now
Begin working on the DO NOW pretest you grabbed off of the door
If you do not have a periodic table or paper go collect these things.

2. Catalase breakdown of Hydrogen Peroxide
Trimester 3: REACTIONS
2H2O2(aq)  2H2O(l) + O2(g)
Catalase breakdown of Hydrogen Peroxide

3. Key Point #1 (write this down!)
Valence Electrons:
- Electrons located on the outermost orbital of an atom (furthest from the nucleus)
- Can be determine by looking at what group elements are located in
- Valence electrons form bonds between elements to make compounds/molecules
2H2O2(aq)  2H2O(l) + O2(g)

4. What element is the ONE exception to this trick?
VIII
II III IV V VI VII
What element is the ONE exception to this trick?

5. Key Point #2
Ions:
- Form when an atom gains or loses electrons in order to reach 8 valence electrons
- 2 types:
- Cation (positive, lose electrons)
- Anion (negative, gain electrons)
To determine what ion will form…
1. Identify valence electrons
2. Determine if will lose or gain electrons & how many
3. Add total protons & electrons to determine the charge

6. Got it?
What ion does Phosphorous (P) form? a. P+3 b. P-3 c. P+5 d. P-5

7. Key Point #3 Ionic Bonds:
- Form when an electron is transferred from one atom to another
- Form between METALS and NONMETALS

8. Metals vs. Nonmetals

9. Key Point #4 B Lewis Dot Structures:
- Models of the valence electrons of an atom
Steps to Drawing Lewis Dot Structures
1. Determine how many valence electrons an atom has
2. Write the Element symbol
3. Surround the symbol with dots that match the # of valence electrons (only 2 on each side)
Example: Boron B

10. 3 Steps to Determining Compound Formulas (we’re making bonds!)
Step 1: Determine what ion will form for each element Step 2: Match your elements to make a neutral compound (positive goes first!) by crossing and dropping the charges Step 3: Simplify if possible (1’s are invisible OR find the Lowest Common Multiple) Lets do some examples…

11. Carbon Dioxide(CO2): O C O
Key Point #5
Covalent Bonds:
- Forms when electrons are SHARED between atoms
- Form between NONMETALS only
When finished with the practice draw the Lewis Dot Structures for these covalently bonded atoms & have them checked by Ms. Herndon:
Water (H2O): H O H
Carbon Dioxide(CO2): O C O

12. Exit Ticket 1
Directions: You have 10 minutes to complete the Exit Ticket to the best of your ability. You MAY NOT use notes, but you may use a Periodic Table. When finished submit to the class bucket, return your binders, and show Ms. Herndon you have your HW.