1. Monday, December 5
When you made butter in the lab on Friday, was that a chemical or physical change? Explain.

2. The cream went through a physical change when it turned into butter
The cream went through a physical change when it turned into butter. The fat globules clumped together causing the liquid to be squeezed out of the solid mass. This physical change is reversible. The butter can be melted and mixed with buttermilk to make cream again.

3. Forming Bonds Produces heat, light
Exothermic
Endothermic
Forming Bonds
Produces heat, light
Ex: , mixing chemicals to make a glow stick, fireworks, Freezing water into ice
Breaking Bonds
Getting colder
Ex: melting chocolate, melting ice, baking a cake, waffles, alka- seltzer and water.

4. Reaction Rates Think of rate as how fast or slow the reaction happens
What factors influence how fast a reaction happens?
Cooking is a reaction. What do you do when you are starving and want the food to cook faster?

5. 4 Factors that Influence Reaction Rates
Temperature or reactants
Concentration of reactants
Surface area of reactants
Presence of a catalyst

6. 1. Temperature of Reactants
Higher temperatures react faster than lower temperatures

7. 2. Concentration of Reactants
Concentration is the number of particles in a given volume
The higher the concentration the faster the reaction
The lower the concentration the slower the reaction
Two antacid tablets will neutralize a given amount of acid faster than one tablet will.
Higher concentrations of acid in rain erode marble faster than lower concentrations.

8. 3. Surface Area of Reactants
The more surface (matter) area exposed the faster it reacts

9. Surface Area

10. Presence of a Catalyst Something we add to a reaction to speed it up.
IS NOT a reactant and is not consumed in the reaction.
It DOES NOT take part or participate in the reaction.
Takes less energy to make the product

11. Write the question and only the correct answer.
Monday, December 5
Write the question and only the correct answer.
What happens to molecules in a liquid when it changes to a gas? The molecules have:
moved fast enough to break away from each other
moved around toward the bottom
moved slowly enough to break away from each other
moved toward the other molecules

13. If you want your Cartesian divers, get them today because they are going bye-bye after school.