Making a volcano is a practical way for showing off physical science knowledge about geology. Place an empty film canister on a piece of cardboard. Play-dough or mud can be molded around the canister for a realistic effect. Put 1 tablespoon of baking soda in the canister. In a separate bottle, mix a few drops of red food coloring and 1/4 cup of vinegar. When it's time for demonstrating a volcanic eruption, pour the vinegar and food coloring mixture into the canister for an instant recreation.
When placed in regular tap water, eggs sink. For this project representing physics, the student will demonstrate how eggs float when salt is added into the water, creating a natural buoyancy for the egg and teaching how saltwater is naturally denser than tap water. Fill two glasses or beakers with water and place an uncooked egg inside each glass. Leave one glass alone, and in the other add 1/2 tablespoon of salt, stirring the salt until it dissolves. Add salt until the egg is floating on the surface of the water. Record results for presentation.
Demonstrate the combined sciences of chemistry and geology by making crystals with ingredients found at home in the kitchen. Filling a drinking glass with water, add a teaspoon of salt and stir until dissolved. Continue adding salt until salt will not dissolve any more. Tie a piece of string onto a pencil, making sure the string goes almost to the bottom of the glass. Place string in the glass and balance the pencil on the glass rim. Experiment with crystal size by adding more salt on a daily basis. Repeat the process for a week and record results each day of the crystals' growth.
Demonstrate heat transfer by cooling down room temperature canned sodas at as rapid a pace as possible. For this physical science project, prepare a bucket with ice only, another with a 50/50 mixture of ice and water and make sure there is access to a freezer. Taking three warmed cans of soda, place one in each suggested environment. Open the tops of the cans and test the temperature of the soda with a thermometer every 5 minutes. The project is complete when the temperature has stabilized. Log all results and record temperatures to be included in the final presentation.