Science Projects That Are Really Popular

Mentos and Diet Coke Fountain

A dramatic reaction takes place when Mentos candy is mixed with Diet Coke. When Mentos is dropped into a 2-liter bottle of soda a stream of fizzy foam shoots out of the bottle several feet into the air. The surface of the candy rapidly initiates bubble formation in the soda bottle, and with nowhere to go, the bubbles shoot out of the bottle like a geyser. Beware, the demonstration will cause a mess.

One of the most classic science experiments is building a volcano that erupts on command. The volcano is simply a creative way to showcase the reaction that happens between baking soda and vinegar. Build a volcano out of clay or paper mache, leaving a hole big enough at the top to pour your ingredients in. Make sure there are no cracks. Once ready, pour 4 tablespoons of baking soda, a couple drops of dish soap, and about a half a cup of water into the volcano. Pouring vinegar into the volcano (about half a cup) will cause the reaction to begin. Foam and bubbles will erupt out of the top and down the sides of your volcano.

Kids will feel like a spy when they learn how to use lemon juice to write secret messages that are invisible to the naked eye. Add a couple drops of water to a bowl of lemon juice to prepare your mixture. Dip a cotton swab into the mixture and write your message on a sheet of white paper. When it dries you will not be able to see anything, but holding your paper up to a heat source like a lamp will expose the message. This is because the lemon juice oxidizes with heat and begins to turn brown.

Create an electric current with a potato battery. Using a couple of potatoes, copper wire, galvanized nails, clips and a device that measures voltage you can gauge the amount of electricity you create. Potatoes are not electrically charged, but they act as a transfer material for an electron transfer. The copper and zinc in the wire and nails react, and when connected in a circuit, can power an LED clock or register voltage on a meter.