1) Draw the Lewis structure for ozone, O3.

2) What does the word hybridization mean? Use your own words.

A resonance structure is a structure that occurs when it is possible to draw two or more valid electron dot structures.

In the case of ozone, neither structure actually exists, but rather the actual bonding is an average of the two structures.

Definition of hybridization ….

-Learn what a sigma bond looks like

-Learn what a pi bond looks like

-Understand the concept of orbital hybridization and how it changes the bonding in an atom such as carbon

When two atomic orbitals combine to form a bond along the axis between two atoms … we call it a sigma

bond ()

When two “p” orbitals combine side by side we say they overlap to form a pi () bond

Pi bonds exist when we have double and triple bonds

Single bond – 1 sigma bond

Double bond – 1 sigma and 1 pi bond

Triple bond – 1 sigma and 2 pi bonds

The electron structure of a carbon atom can be written as:

Based on this model, we would predict that carbon atoms should form two covalent bonds??!!

Instead carbon atoms almost always form 4 bonds.

Why????

Hybridization

hybridization

1 s + 3 p = 4 sp3

(All 4 orbitals are now equal at the 2nd energy level)

Regular Carbon Aufbau Diagram Hybridized Carbon Aufbau Diagram

Electrons must be distributed among the new orbitals. Since these hybrid orbitals are equal in energy, the electrons must distributed according to Hund’s Rule.

4 sp3 orbitals

4 sp3 orbitals bond with4 hydrogen atoms - methane

sp3 carbon

Overlap hereis known assigma bond

Let’s predict what sp2

hybridization around a carbon might look like?

Take out your white boards

sp2 hybridization

sp2 hybridizationcarbon double bond - ethene

Can you predict sp geometry around a carbon?

sp hybridization

sp hybridizationcarbon triple bond - acetylene

sp hybridizationcarbon triple bond - acetylene

234-236 in your text discusses these examples

Summarysp3 hybridization involves

single-bonded carbon

sp2 hybridization involves double-bonded carbon

sp hybridization involves triple-bonded carbon