VSEPR Part 2

VESPR Theory Part II

We will:
1) Determine Steric Number
2) Recognize 2D symbols for 3D Molecular Geometry
3) Steps of Recognizing Molecular Shapes

I will:
Apply my understanding and knowledge

Steric Number

The number of atoms bonded to the central atom plus the lone pairs

Multiple Choice

What is the steric number for SeO₂?

• 2

• 3

• 4

• 5

2D to 3D Molecular Geometry

Signs and Symbols

Dashed broad/triangular shapes represent chemical bonds and groups extending behind the page.
Solid wedged triangular shapes represent chemical bonds and groups extending towards the page.
Solid lines represent chemical bonds on the same plane as the paper.

Multiple Choice

Which symbol indicates that the non-central atom is located behind the central atom.

VSEPR

Steps to identifying molecular shapes.

1) Determine the central atom.
2) Draw the Lewis dot structure.
3) Identify steric number.
4) Identify the number of lone pairs.
5) Use your chart.

Multiple Choice

Choose the correct shape for this molecule:

• Trigonal planar
• Trigonal pyramidal
• Tetrahedral
• Linear