1. Notes #1: Covalent Bonding/ Lewis Dot Structures
WCHS Chemistry
NEED PERIODIC TABLE & A PENCIL!!
QUIZ THURSDAY!

2. QUICK REVIEW! Valence Electrons = Outermost electrons!
How to know how many…?
GROUP NUMBER!
Octet Rule =
Atoms are most stable when surrounded by 8 valence electrons!
Exceptions?
H and He only have 2
What is an ion…?
Charged atom!
Write the formula for Sodium Oxide
Na2O

3. IONIC BONDS
Electrons are gained or lost so opposite charges attract
Charges must add up to be NEUTRAL!
Typically involves a metal and a nonmetal
Ex: NaCl, AlBr , MgF, KS, CaO, LiBr

4. What about something like...-1 -1 Cl Cl
Cl2
7 v.e.
7 v.e.
Covalent Bonding
Involves the sharing of e-
Typically only involves NONMETALS
****Hydrogen IS a nonmetal.
Only wants 2 v.e.! 1s2
Ex: CO2 H2O O2 N2

6. LEWIS DOT STRUCTURES: SINGLE ELEMENTS
Show an atom’s valence electrons!
Rules for a single element:
1. Fill each side one at a time
2. Maximum of 2 e- on each side
This can change ONLY when bonding!!!!! K Se Ne O Br P Al Mg

7. LEWIS DOT STRUCTURES: COVALENT BONDS
Start with the element that wants the most e-
Be prepared to move e- around to line up with others for sharing!!!
Circle ALL of the e- for EACH element!
They should have 8 (or 2) and line up

8. Cl2
HCl

9. CH4 O2

10. N2