Popular elementary school science projects include fruit batteries and homemade lava lamps, according to Education.com. Some other common ideas are do-it-yourself hovercraft, experiments on how light affects the growth of plants, self-inflating balloons and experiments investigating the rates at which different foods grow mold.
Creating fruit batteries allows students to explore topics in electricity and magnetism, explains Education.com. Meanwhile, homemade lava lamps allow elementary school children to investigate how chemically different substances interact with one another, notes Kidzworld.
When creating fruit batteries as a science fair project, students can test several different types of fruits, such as tomatoes, kiwis, lemons and oranges, to measure how much of an electrical current each fruit produces, notes Education.com. The project uses electrodes of two different metals, copper and zinc, to generate electricity using the citric acid found naturally in fruits as an electrolyte. A light-emitting diode, or LED, is attached to the fruit battery and converts the electricity generated into visible light.
To make a lava lamp, science students add water, glitter and food coloring to a jar of oil, explains Kidzworld. The water and oil do not mix because the oil, which is not as dense as the water, rises. However, when the students drop an Alka-Seltzer tablet into the jar, a chemical reaction between the Alka-Seltzer and water produces carbon dioxide gas, which rises through both the water and the oil, pulling beads of colored water with it to produce a lava lamp effect.