1. Collision Theory
Mrs. Kay

2. A chemical reaction…
In order for a chemical reaction to occur, the particles of the reactants must come in contact and collide with each other.
by calculating how many collisions are taking place per second and how quickly product is being produced, we learn that most collisions are not successful (no product formed)

3. to think that reactant particles collide and products are automatically produced is over simplified.
There must be other requirements for a collision to be successful.

4. The Collision Theory
is an explanation of what is necessary for a chemical reaction to occur.
This theory states when a chemical reaction takes place, the reactant particles must meet two conditions (or requirements) during collision for the collisions to be successful

5. Conditions…
Particles must collide with a certain minimum amount of energy, called activation energy.
This energy is required to break chemical bonds in the reactants.
The energy of each particle is not important, it is the energy of the collision.

7. Particles must collide with the proper geometry or orientation for atoms to come in direct contact and form the chemical bonds of the products.

8. If both of these conditions are not met, particles will merely collide and bounce off one another without forming products.

9. Although, the percentage of successful collisions is extremely small, chemical reactions still take place at a reasonable rate because there are so many collisions per second between reactant particles.

10. Practice: 1. State the collision theory for chemical reactions.
2. Why is not enough for reactant particles just to collide in order to produce products?
3. In spite of the extremely small percentage of successful collisions, why is it that chemical reactions are still observed to take place at a reasonable rate?
4. Why is the energy requirement needed for a successful collision?
5. Why is the geometry or orientation requirement needed for a successful collision?

11. More Practice:
Pg 478 # 5-7
Read Pg