Three of the most popular science fair projects for high school are whether or not tea stains your teeth, whether heat affects sound frequency, and whether or not all liquids take the same amount of time to evaporate, according to Education.com. The results are based on user ratings.
To conduct the tea project, fill three containers with equal amounts of coffee, tea and cola, says Education.com. Place a hollowed egg shell in each container, and allow the shells to sit for one day. Remove the shells, and describe the appearances of each shell on a chart. Repeat for two more days, and compare the results on the third day to come up with a conclusion.
To carry out the sound frequency experiment, build a makeshift parabolic microphone dish, says Education.com. Connect the microphone to a device loaded with an application that counts sound frequency. In the experiment, the dish is placed 6 1/2 feet away from an oven, a metronome tuner tuned to a middle C is played, and a reading is taken. This is repeated at 225 degrees, 325 degrees, 425 degrees and 450 degrees Fahrenheit to determine if the frequency climbs as the temperature increases.
The evaporation project uses equal amounts of water, orange juice, nail polish remover and alcohol in beakers, as stated by Education.com. Each liquid is left alone for one week, and results are recorded each day to determine if evaporation rates are equal among the four liquids.