Honors Shapes to Know: See Honors Packet– Linear– Trigonal Planar– Bent (with 3 e- regions and with 4)– Trigonal Pyramidal – Tetrahedral– Trigonal Bipyramidal– SeeSaw– T-Shaped– Linear– Octahedral– Square Pyramidal– Square Planar

• VSEPR SHAPES FOR HONORS: http://youtu.be/FjjhUI4wFTE• Example of Shapes (honors): http://youtu.be/i3FCHVlSZc4

Honors

Honors

HONORS

HONORS

Effect of Nonbonding Electrons on Bond Angles

– Since electrons in a bond are attracted by two nuclei, they do not repel as much as lone pairs.

– Bond angles decrease as the number of lone pairs increase.

OHH

104.5O107O

NHH

HC

H

HHH109.5O

HONORS

Exceptions to the Octet Rule (Honors)

• Less than Octet– Ex: BeH2

• Odd Number of Valence Electrons– Ex: NO

• More than Octet– Ex: SF6

Molecules with Expanded Valence Shells

• Trigonal bipyramidal electron geometries:

• Plane contains three electrons pairs.

• • Fourth and fifth

electron pairs located above and below this plane.

HONORS

To minimize e- repulsion, lone pairs are always placed in equatorial positions.

HONORS

Molecules with Expanded Valence Shells

• Octahedral electron geometries

• Plane contains four electron pairs.

• Fifth and sixth electron pairs located above and below plane.

HONORS

Hybridization of Orbitals (Honors)

• To know hybridization type simply count # of e- groups or “domains” around central atom

sp = 2 e- domains (linear e- geometry)sp2 = 3 e- domains (trig. planar e- geometry)sp3 = 4 e- domains (tetrahedral e- geometry)sp3d = 5 e- domains (trig. bipyramidal e- geometry)sp3d2 = 6 e- domains (octahedral e- geometry)

sp2

sp3

sp3d

Resonance(Honors)

• Electrons “resonate” between multiple bonding sites.

• Adds strength to all the bonds.• Check if it is possible to draw double or triple

bonds at more than one bonding site.

Sigma and Pi Bonds (Honors)

• Sigma Bond: – End to end overlap of orbitals– All single bonds are sigma– One of the bonds in a multiple

bond is a sigma

• Pi Bond: – Side to side overlap of orbitals.– Found in double or triple bonds.

Bond Length and Bond Strength

• Longest = Single Bonds• Shortest = Triple bonds

HONORS

Bond Strength

• Strongest (hardest to break)= triple bonds• Weakest (easiest to break) = single bonds

HONORS

Honors

Good for Review!!

• Crash Course Video: Molecular Geometries and Electron Orbitals

• http://www.youtube.com/watch?v=cPDptc0wUYI

• Orbital Hybridization: (10 min) http://www.youtube.com/watch?v=d1E18tBTlBg