1. Unit 8: Lewis Dot (again…)
Objectives
How to diagram simple lewis dot structures.
How to determine double and triple bonding.
Simple Exceptions to octet rule
Tinyurl.com/OCHSChemH23
Words to know
Valence electrons Octet Octet Rule
Double Bond Triple bond
Electron Group Lone Pairs

2. Steps to Lewis Dot 1) Count total valence electrons
2) Arrange atoms, least electronegative in middle (when applicable)
3) Connect atoms with single bond (2 electrons)
4) Distribute remaining electrons on outer atoms to fulfill octets
5) Place any remaining electrons on central atom
6) If not enough electrons make double or triple bonds
Octet rule = nonmetals tends to bond to have 8 valence electrons
**Hydrogen** = notable exception (just 2 electrons)
Try the following
H2S
SiH2Cl2

3. Lewis Dot Double and Triple Tinyurl.com/OCHSChemH23
1) Try SiO2
2) C2F2

4. Octet Rule: Notable Exceptions
Exceptions that have less than 8
1) BF3 (B) 2) BeCl2 (Be … just pretends it’s not a metal)
Exceptions that have more than 8
1) PCl5 (P) 2) SF6 (S) 3) XeF4 (Xe)