1. B. Ionic bonding and Structures of Ionic Compounds
Ionic Compounds Containing Polyatomic Ions
Polyatomic ions work in the same way as simple ions
The covalent bonds hold the polyatomic ion together so it behaves as a unit

2. Writing Lewis Structures for Polyatomic Ions

3. 2-
[SO4]2-

4. -
[NO2]-

5. +
[NH4]+

6. Objectives
SWBAT understand molecular structure, be able to predict molecular geometry from the number of electron pairs and to apply the VSEPR model to molecules with double bonds in a virtual laboratory.

7. A. Molecular Structure
The atoms in a molecule have a three dimensional arrangement,
Water - bent
LQHS

8. A. Molecular Structure
Linear structure – atoms in a line
Carbon dioxide

9. A. Molecular Structure
Trigonal planar – atoms in a triangle
BF3

10. A. Molecular Structure
Tetrahedral structure
Methane CH4

11. B. The VSEPR Model
Valence shell electron pair repulsion (VSEPR) model
Molecular structure is determined by minimizing repulsions between electron pairs

12. B. The VSEPR Model
Two Pairs of Electrons
BeCl2
180o - linear
(Note, this is an ionic compound exception AND an octet rule exception!)

13. B. The VSEPR Model
Three Pairs of Electrons
BF3
120o – trigonal planar

14. B. The VSEPR Model
Four Pairs of Electrons
CH4
109.5o – tetrahedral

15. B. The VSEPR Model

16. B. The VSEPR Model

17. C. Molecules with Double Bonds
When using VSEPR model to predict molecular geometry of a molecule
a double bond is counted the same as a single electron pair
Virtual Lab
LQHS