Test how various substances affect the rate of water evaporation. Fill three clear drinking glasses with a similar amount of water. Leave one glass untouched, add salt to the second and sugar to the third. Leave the three glasses in an open space and track how quickly the water evaporates in each glass.
This project illustrates the basic science that is behind the concept of salting an ice-encrusted sidewalk. Take three ice cubes and place one in each of three small bowls. Leave one ice cube alone, sprinkle the second cube with salt and the third with sand. Compare the rate each cube melts and determine which method is most effective in turning ice back to water.
Test how the addition of certain substances can alter the rate that water freezes. Take four plastic drinking cups and add a similar amount of water to each. Leave one glass of water untouched, then add salt to the second, sugar to the third and soda to the fourth. Place all four glasses in the freezer and begin checking them after 45 minutes. Check them every 15 minutes afterward, tracking which combination is freezing the fastest or slowest. How does this compare to the results you got with similar substances in the earlier experiments?
What affects an object's ability to float in water? Fill a glass with water. Get a medium-sized piece of clay and roll it into a ball. Place it in the water to see if it floats. Remove the clay, dry it off and make it into a new shape. Does the shape affect the buoyancy of the clay?