Science fair

MATERIALS
* 1/2 cup milk
* 1/2 cup whipping cream (heavy cream)
* 1/4 cup sugar
* 1/4 teaspoon vanilla or vanilla flavoring (vanillin)
* 1/2 to 3/4 cup sodium chloride(NaCl) as table salt or rock salt
* 2 cups ice
* 1-quart ZiplocTM bag
* 1-gallon ZiplocTM bag
* themometer




rocedure
1. Add 1/4 cup sugar, 1/2 cup milk, 1/2 cupwhipping cream, and 1/4 teaspoon vanilla to the quart ziplocTM bag. Seal the bag securely.
2. Put 2 cups of ice into the gallon ziplocTM bag.
3. Use a thermometer to measure and record thetemperature of the ice in the gallon bag.
4. Add 1/2 to 3/4 cup salt (sodium chloride) to the bag of ice.
5. Place the sealed quart bag inside the gallon bag of ice and salt. Seal the gallonbag securely.
6. Gently rock the gallon bag from side to side. It's best to hold it by the top seal or to have gloves or a cloth between the bag and your hands because the bag will be coldenough to damage your skin.
7. Continue to rock the bag for 10-15 minutes or until the contents of the quart bag have solidified into ice cream.
8. Open the gallon bag and use thethermometer to measure and record the temperature of the ice/salt mixture.
9. Remove the quart bag, open it, serve the contents into cups with spoons and ENJOY!


Explanation
Ice has toabsorb energy in order to melt, changing the phase of water from a solid to a liquid. When you use ice to cool the ingredients for ice cream, the energy is absorbed from the ingredients and from theoutside environment (like your hands, if you are holding the baggie of ice!). When you add salt to the ice, it lowers the freezing point of the ice, so even more energy has to be absorbed fromthe environment in order for the ice to melt.

MEMBERS

Vanessa Gallegos

Virginia Velasco

Victoria Orozco

Valeria Susell

Jose Ramon Rodriguez

Jesus Maldonado