As we discussed last week, science isn’t just for the lab. Whether it’s raining, the usual activities are boring, or you just love science, here are 10 great experiments kids can do at home (with adult supervision). These experiments use ingredients you probably have sitting in your cabinets to create some fun demonstrations of basic principles of chemistry, biology, and physics. Happy exploring!
10. The Water Bottle Egg Separator
What you’ll need: Raw egg, two bowls (or plates), empty water bottle, [optional] food coloring
How does this work?
When you squeeze the bottle, you force air out. When you place the mouth of the bottle over the yolk and stop squeezing, you create suction, as air (and yolk) rush to fill the available volume. The air pressure within the bottle is lower than outside the bottle, so the air pushes the yolk into the bottle.
9. Oobleck, a Non-Newtonian Fluid
What you’ll need: Water, cornstarch, mixing bowl, [optional] food coloring. This experiment can be a bit messy, so throw on some old clothes and do it in a place where you can make a mess (the backyard is ideal).
How does this work?
Oobleck, named after the Dr. Seuss book, Bartholmew and the Oobleck, is a non-Newtonian fluid. This means that sometimes (like when it is being poured) it acts like a liquid, but when force is acting on it (like when you press down with your hand), it behaves like a solid.
8. Blow Up a Balloon Using Baking Soda and Vinegar
What you’ll need: White vinegar, bottle with narrow mouth, balloons, baking soda, [optional] food coloring
How does this work?
This is the same technique that is often used to power model volcanoes at science fairs, but you can enjoy it without going to the trouble of building a volcano. When the baking soda and vinegar are combined, they undergo a two-part reaction to produce the carbon dioxide (CO2) that blows up the balloon.
7. Use Capillary Action to Dye Flowers
What you’ll need: Freshly cut white flowers (daisies and carnations work well. You can even use celery if you don’t have any flowers), glass or jar, food coloring, [optional] scissors. You’ll also need some patience, as this experiment can take up to 24 hours to show full results (though you should see some results in 4-6 hours).
How does this work?
As water evaporates of the flower’s petals, it draws up new (colored) water through its stem, and the color flows through to the petals.
6. Use Soda to Understand Density
What you’ll need: Unopened cans of diet soda and regular soda, large container filled with water (the bathtub or a pool will work too—but grab a grown-up before you try!).
How does this work?
The differential in the density between diet and regular soda (caused by the addition of sugar) causes one kind of soda to sink to the bottom, while the other bobs up.
5. The “Magic” Plastic Bag
What you’ll need: A Ziploc-type bag, several sharpened pencils, enough water to fill the bag (a cup or so). It’s best to do this experiment over a sink or tub, so that if you give into the temptation to pull the pencils out after the experiment, you don’t spill water everywhere!
How does this work?
The Ziploc bag is made up of flexible polymers. When the bag is pierced, the plastic stretches and creates a tight seal around the pencil, so the bag doesn’t leak.
4. Clean Pennies with Vinegar
What you’ll need: Dirty pennies, one dime, 1/4 cup white vinegar, one teaspoon of salt, cup of water, two non-metal bowls, paper towels. You also might want to wear something to protect your eyes (safety glasses, goggles, even sunglasses will work in a pinch!).
How does this work?
The acid in the vinegar reacts with the salt to remove the copper oxide that was making the pennies look dirty. If you don’t rinse them off after the vinegar, malachite (bluish-green in color) will form. If there’s enough copper oxide in the vinegar solution after you clean some pennies, when you add the dime, the metal will attract the copper oxide and take on a new color.
3. Help Tissue Paper Ghosts “Fly” Using Static Electricity
What you’ll need: Balloon (blown up), small ghost cut out of tissue paper and taped to a desk or table, something that you can rub the balloon against to generate static electricity (your clothing or hair will work well!).
How does this work?
Rubbing the balloon generates a negative charge on the balloon. When the balloon is held over the positively charged tissue ghosts, it attracts them, causing the ghosts to “fly.”
2. Make Raisins “Dance”
What you’ll need: Raisins, bottle of seltzer water/club soda, clear drinking glass
How does this work?
The tiny bubbles of carbon dioxide (CO2) in the soda catch on the wrinkles of the raisins. As the bubbles latch on, the raisins become lighter and rise to the surface. When they hit the surface, the bubbles pop, the raisins become heavy again, and fall back down. This process makes the raisins look like they are dancing in the glass.
1. Propel Colored Milk into Crazy Swirls Using Surface Tension
What you’ll need: Disposable plastic bowl/plate, whole milk or half & half (enough to cover the bottom of the bowl/plate), food coloring, Q-tip, liquid dish soap, a place where you can make a mess and clothes you can get dirty.
How does this work?
Food coloring isn’t as dense as milk, so initially, the drops you add float on the surface. However, the addition of the dish soap on the tip of the Q-tip breaks the surface tension of the milk by dissolving the milk’s fat molecules. The food coloring moves along the surface with the milk, moving away from the soap.