1. VSEPR Model and the Resulting Shapes

2. VSEPR When atoms bond, every and
____ need their own space. As a result, they make a three dimensional molecular shape. This is the basis of the Valence Shell Electron Pair Repulsion (VSEPR) model.
atom
electron
pair

3. VSEPR Shapes 1 N/A Linear 2 Linear 1 or more 2 Bent
How many atoms are surrounding the central atom?
Are there dots (lone pairs) on the central atom?
VSEPR Shape (with Lone Pairs Shown)
VSEPR Shape (without Lone Pairs Shown)
Name of VSEPR Shape 1
N/A
Linear 2
Linear
1 or more 2
Bent

4. Trigonal Planar 3 Trigonal Pyramidal 3 1 Tetrahedral 4
How many atoms are surrounding the central atom?
Are there dots (lone pairs) on the central atom?
VSEPR Shape (with Lone Pairs Shown)
VSEPR Shape (without Lone Pairs Shown)
Name of VSEPR Shape
Trigonal Planar 3
Trigonal Pyramidal 3 1
Tetrahedral 4

5. VSEPR and Polarity

6. Since all atoms have different electronegativities, a “
Since all atoms have different electronegativities, a “ ” for the electrons in a bond begins when atoms bond.
When an atom bonds with another one of itself (example F-F), the difference in electronegativity is This is known as covalent or covalent bond.
When an atom bonds with different atoms, they can be or _________ covalent bonds, depending on the differences in electronegativities.
Tug of war
zero
nonpolar
pure
polar
nonpolar

7. What happen when the electronegativity isn’t equal
large
When the difference in electronegativity is , an electron is and bonding results.
When the difference in electronegativity is ______ ____________, the electrons are __________ ____________ and bonding results.
transferred
ionic
very
small (<0.5)
shared
nonpolar
equally

8. moderate
When the difference in electronegativity is , there is sharing. Resulting in a covalent.
As a result, the electrons spend more time around the electronegative ( ) atom, which makes it slightly The weaker atom becomes slightly .
This results in the polar bond being a – two poles
unequal
polar
more
stronger
negative
positive
dipole

9. Polarity of Molecules
Overall, molecules can be or , depending on the results of the molecular “ ”
If the VESPR shape makes it a molecule then the result is
If VESPR shape makes it a molecule then the result is .
polar
non-polar
Tug of war
symmetrical
nonpolar
asymmetrical
polar

10. So, what does this mean to us?
To determine if a molecule is polar or not, ask yourself:
Are there dots on the central atom? If __________________ , it is automatically __________________. If not, then ask yourself:
Are all the elements around the central atom the same (or are the two atoms the same in the case of the two atom linear molecules)? If __________________, It is __________________.
yes
polar
yes
NONPOLAR

11. Let’s look at H2O
Water has _____________ which makes its shape __________________, so this would make water __________________.
 Ability of a substance to dissolve is based on polarity … _____________ dissolves _____________.
So, _____________ dissolves polar and _____________ dissolves non-polar.
Water is polar, so it dissolves _____________ substances
dots
asymmetrical
polar
like
like
polar
nonpolar
polar