You can create a chemical reaction with a hard-boiled egg and vinegar to create a "naked" egg -- an egg without a hard shell. To do this, follow the instructions detailed on the Exploratorium website: Place several hard-boiled eggs in a container so that they don't touch. Pour vinegar over the eggs until the eggs are completely covered; allow them to sit for 24 hours. Repeat the process, carefully removing the egg and then covering with fresh vinegar. Allow this to sit for another 24 hours. Rinse the eggs carefully. For an advanced chemistry project, detail the chemical changes occurring in the reaction between the shell and vinegar. Explain why the membrane doesn't dissolve. Explain how scientists could use this chemical reaction in other areas, such as garbage disposal.
Perform a simple experiment with sugar crystals that gives you a fun treat at the end.
In 2007, Leo S. Harvath entered the California State Science Fair with a project that explored the formation of sugar crystals in various temperatures. You can repeat this test, following a simple sugar crystal recipe and placing these in the freezer at room temperature and in a warm environment, such as a greenhouse. You test the effects of temperature on crystal formation and test the effects of other chemicals on crystal formation. At the end, eat your sugary project -- as long as you didn't add other chemicals.
You can create a crazy material that performs in unusual ways, turning from a liquid to a solid with one touch. Following the recipe on the Science is Fun website, slowly mix 2 tbsp. water into 1/4 cup dry cornstarch. Keep adding water, very slowly, until no powder remains. When you finish, notice how stirring turns the cornstarch mixture into a liquid. When you tap it with your finger, it turns into a solid. Pick up the mixture and knead it in your hands; it stays solid. As soon as you remove the pressure of your hands, the cornstarch mixture melts and becomes a liquid. Explain how the chemical properties of the mixture make the state of the matter change -- although actually, it doesn't change; it just doesn't follow certain Newtonian principles. Think of ways that scientists can use this material to help in various fields, such as construction.
For a science project, you can create a homemade lava lamp using food coloring, water, vegetable oil and salt, according to the instructions on the Science Bob website. To do this, mix together the food coloring and water in a clear plastic or glass cup. Add a bit of oil to the top of your water. The oil floats on top of the water -- because of differences in density -- until you add salt. The density of salt drags down some of the oil with it until the salt dissolves, releasing the oil to rise to the surface. Add more salt to continue this effect. Use your project to postulate how the reaction between salt and oil could be used in certain practical applications, such as for water cleanup.