Making Ice Cream: Watch a liquid (milk) change to a solid
Standards:11.A.1a Describe an observed event.
13.B.1d Identify and describe ways that science and technology affect people’s everyday lives (e.g., transportation, medicine, agriculture, sanitation, communication occupations).
Measure one cup of milk, two tablespoons of sugar, and one-half teaspoon of vanilla extract into a pint-size zip baggie. Squeeze out as much air as you can. Put the pint-size baggie inside the gallon-size baggie. Add four cups of crushed ice and six tablespoons of rock salt to the gallon size baggie. Squeeze all the air out and seal. Let the students shake the gallon-size bag vigorously for several minutes. They can problem solve about the best way to do this. You could also break the students up into teams or into twos. When the ice cream is the desired consistency, (thick and creamy), take the pint-size baggie out of the gallon size baggie and rinse it off and remove the salt.
Materials: Rock salt, sugar, whole or low fat milk, crushed ice, vanilla extract, small cups, spoons, measuring cups, measuring spoons, pint-size zip baggies, gallon size zip baggies.
Some Things Float & Some Things Don't!
Bring in 6 objects made from different materials (wood, metal, fruit, plastic). Pass each object around the class, allowing each student to hold and observe each thing. Make a hypothesis: will it sink or float, and test it. Place each item in a tub of water and watch it sink or float. Make a list on the board of the things that sunk and those that floated. Discuss the similarities and differences of each group, why did some things float and some things sink?
Materials: wood, meatl, plastic, fruit, a tub