In lesson 10, the students will make ice cream. They will observe as cream is frozen to transform into ice cream. In lesson 11, the students will melt solid pieces of chocolate to make a liquid chocolate sauce.
The students will observe two demonstration recipes of how temperature affects the outcome of a recipe. Making ice cream demonstrates how liquid ingredients transform into a solid as they are frozen. The students will make ice cream using a plastic bag or coffee can. I chose the plastic bag recipe because the students will be able to see how much energy it takes to mix the ice cream ingredients. The students will have to vigorously shake the mixture. Let the ice cream freeze over night. Either recipe for ice cream can be found at http://crafts.kaboose.com/ice-cream-in-a-bag.html or http://crafts.kaboose.com/coffee-can-ice-cream.html.
The next day the students will make chocolate sauce. Use either chocolate chips or chocolate wafers. The wafers can be found at a craft store. Use a double boiler to melt the chocolate. This recipe demonstrates how a solid chunk of chocolate is manipulated and changed into a smooth liquid as it melts. Chocolate is a poor conductor of heat, to speed the process of melting, use small pieces of chocolate. Chocolate chips or wafers are recommended. If using a chocolate bar chop the chocolate into small pieces. The students will use the chocolate sauce to put on top of their ice cream. The students will observe and record the changes that have occurred to the bag of cream and the chocolate morsels.
The students now have enough background knowledge about liquids and solids. The students can discuss what changes would occur if the ice cream were to be left out. The ice cream would begin to melt and reenter the liquid phase. The students can discuss what changes would happen in the chocolate was left undisturbed. The chocolate would overtime begin to harden and solidify.