The physical properties of soda can make for some educational and entertaining science projects. Even different types of soda can cause varying reactions under the right conditions. There are soda science projects that require easily obtainable materials to exhibit different scientific phenomena.
Raisins in Soda
This project uses raisins, clear carbonated soda and a glass. The soda is poured into the glass and then a few raisins are dropped in; the raisins promptly sink to the bottom. But after a few seconds, the raisins will rise to the surface. Then they'll sink again, and soon they'll be "dancing" up and down the glass. This happens because, "The surface of the raisin traps tiny bubbles of air when you drop them into the glass," says The Teacher's Corner website. "These tiny bubbles collect carbon dioxide from the soda and begin to grow. When the bubbles grow large enough, they lift the raisin. As they reach the top, the bubbles pop and the raisin sinks again." Different types of soda can also be used because sodas with more fizz will cause a more dramatic reaction. This experiment exhibits how a gas, in this case carbon dioxide, can react in a liquid.
Corrosiveness of Soda
The American Dental Association says that drinking too much soda can damage your teeth. This project from the Science Fair Adventure website shows which type of soda is the most corrosive and therefore the most harmful to tooth enamel. This experiment uses one small bottle or can each of Dr. Pepper, Sprite, Pepsi, Mountain Dew, Coca-Cola and distilled water. You'll also need six plastic cups and six tarnished pennies. The pennies are then dropped into cups containing each of the sodas and the water, then labeled to show which is which. The cup of water will serve as your control. The appearance of the pennies is observed and recorded each day. The soda that removes the tarnish the fastest is hardest on your teeth enamel.
Mentos and Soda Geyser
This is a science project best performed outside. It uses Mentos candy and a two-liter bottle of soda. According to the Steve Spangler Science website, dropping the Mentos into the bottle of soda will result in a 20-foot geyser. This requires some quick maneuvers, as an entire roll of Mentos must be dropped into the bottle before it shoots up and gets all over you. A good way to do this is to roll a piece of paper into a tube just big enough to hold the loose Mentos. The tube is positioned over the open bottle and the all the candies are dropped in at the same time. There is some debate as to why these candies react in this way. Spangler believes it's because ingredients in the Mentos break the soda's surface tension. Each candy has thousands of pits on its surface where carbon dioxide bubbles form. "Couple this with the fact that the Mentos candies are heavy and sink to the bottom of the bottle and you've got a double-whammy," Spangler says. "When all this gas is released, it literally pushes all of the liquid up and out of the bottle in an incredible soda blast."