Playing With Food: Eight Science Experiments in the Kitchen
In my first few years of living away from home, I performed a lot of unintentional science experiments in my refrigerator (the variety of colors and textures of mold that can grow on forgotten foods is truly astonishing). But there are plenty of less disgusting—and more fun and educational—ways to learn about science through food. Here are just a sampling of experiments you can try at home with the kids, or even without kids—you don't need to be a minor to appreciate these chemistry tricks:
1. Egg in a Bottle. Demonstrate the effect of temperature on air pressure by resting a hard-boiled egg at the opening of an empty SoBe or similar wide-mouthed bottle, then heating the air in the bottle by dropping in a piece of burning paper. Because the air pressure inside the bottle will drop, the greater air pressure outside the bottle will push the egg into the bottle. If you rub the bottle, the egg will reemerge and grant you three wishes. Okay, not really.
2. Speed of Light S'mores. Measure the wavelength of microwaves after partially nuking a dish layered with marshmallows. Using the distance between waves—evident by the melted spots—multiplied by their frequency (usually listed on the oven), you can get a rough calculation of the speed of light. Don't forget the chocolate and graham crackers!
3. Yeast-Air Balloons. Inflate a balloon by fitting it over a bottle containing a yeast-sugar-water mixture. As the yeast feeds on the sugar, it will produce carbon dioxide that will slowly fill the balloon. Then it's party time.
4. Spaghetti Dance Party. Pick up some new moves from your pasta. Since spaghetti (or vermicelli, as the experiment calls for) is denser than water it will sink. But if you add baking soda and vinegar, bubbles of carbon dioxide will form and cause the noodles to rise and dance around like they're at a Justin Bieber concert.
5. Nails for Breakfast. Is your cereal high in iron? Find out by using a super-strong magnet. If your flakes contain enough iron, the magnet will attract them. Hint: Total works better than Cap'n Crunch.
6. Invisible Ink. Send a secret message while learning about chemistry. Milk, lemon juice or baking soda mixed with water can be used as invisible ink. The milk and lemon juice are acidic and weaken paper, so exposing the message to heat will cause the weakened areas to brown and the words to appear; the baking soda message will be revealed if grape juice concentrate is painted across it, because of the chemical reaction between the two substances. Way cooler than text-message speak, IMHO.
7. You Say Potato, I Say Clock. Turn your spuds into batteries by connecting them to copper wire and galvanized nails, which will produce a chemical reaction strong enough to power an LED clock.
8. An Eyjafjallajökull of Your Own. No list of kitchen science projects would be complete without the miniature volcano. The same reaction that caused the spaghetti to dance in #4 can be used to simulate a lava explosion on your tabletop.