We teamed up with kid science guru Steve Spangler to get the coolest experiments you can try at home, including color-changing milk and a Mentos Diet Coke geyser.
Meet Steve Spangler: scientist, teacher and author with a passion for making science fun. The elementary school science teacher and Emmy-award winning TV personality (he’s a frequent guest on The Ellen DeGeneres Show) has written two books—Naked Eggs and Flying Potatoes and Fire Bubbles and Exploding Toothpaste—on fun science projects you can do at home or school. Here, Spangler gives us 10 amazing experiments that are perfect for science fairs or at-home fun. Parents, be sure to supervise your little scientist-in-training.
Taco Sauce Cleaner
You might have heard that taco sauce is great at cleaning pennies. Try this experiment to find out of if it’s true, and what ingredients might do the trick.
- Dirty pennies (try to collect tarnished pennies that all look the same)
- Taco sauce (mild sauce from Taco Bell works well)
- Tomato paste
- Small plates
- Masking tape or sticky note
- Place two or three equally tarnished pennies on each of four plates. Use masking tape or a sticky note to mark each plate with the ingredient you are testing (vinegar, tomato paste, salt, and water).
- Cover the pennies with the various ingredients and allow them to sit for at least two minutes.
- Rinse the pennies from each test plate with water. Much to our surprise, none of the ingredients did a good job of cleaning the dirty pennies. Where did we go wrong? Maybe two or more of the ingredients work together to react against the copper oxide on the penny.
- Place two or three equally tarnished pennies on each of three plates. Make three signs that say “Tomato Paste + Vinegar,” “Salt + Vinegar,” and “Tomato Paste + Salt.”
- Cover the pennies with each of the mixtures and give the ingredients at least two minutes to react.
- Rinse the pennies under water you will find the clear winner is the mixture of vinegar and salt.
Alka Seltzer Film Canister Rocket
Take school lessons about chemical reactions to new heights with this fun, messy experiment.
- Film canister with a snap-on lid. Look for a clear film canister, if possible. (Fuji brand works best)
- Alka-Seltzer® tablets
- Empty paper towel roll (the cardboard tube) or a similar-sized plastic tube
- Duct tape
- Paper towels for cleanup (you already know that this one is going to be good!)
- Watch or timer
- Adult helper
- Safety glasses
- Put on your safety glasses.
- Divide an Alka-Seltzer tablet into four equal pieces.
- Fill the film canister one-half full with water.
- Get ready to time the reaction of Alka-Seltzer and water. Place one of the pieces of Alka-Seltzer tablet in the film canister. Record what happens.
- Time the reaction and write down the time. How long does the chemical reaction last? In other words, how long does the liquid keep bubbling? Why do you think the liquid stops bubbling? Empty the liquid in the film canister into the trash can.
- Repeat the experiment, but this time place the lid on the container right after you drop in the piece of Alka-Seltzer. Remember to start timing the reaction as soon as you drop the tablet into the water. Stand back! If you’re lucky, the lid will pop off and fly into the air at warp speed! Write down your observations.
Walking on Eggshells
Budding biologists learn all about nature’s perfect packaging in this amazing experiment.
- A few dozen eggs that are in egg cartons (Select large-sized eggs)
- Large plastic trash bags
- Bucket of soap and water
- Some disinfectant
- Barefoot friends
There’s a very high probability that you’ll break a few eggs while attempting to learn this amazing trick. Since raw eggs carry the danger of Salmonella, it’s important that you clean up, wash your hands, and disinfect the area. Even if you don’t break an egg, it’s still a good idea to wash your hands (and feet!) after handling eggs.
- If you just want to attempt the feat of standing on eggs, you’ll only need two cartons of eggs (two dozen eggs). If, however, you’re feeling up to the Walking on Eggs challenge, pick up six or eight cartons of large-sized eggs.
- Spread the plastic trash bag (or bags) out on the floor and arrange the egg cartons into two rows.
- Inspect all of the eggs to make sure there are no breaks or fractures in any of the eggshells. Make any replacements that might be necessary.
- It’s important to make sure all of the eggs are oriented the same way in the cartons too. One end of the egg is more “pointy” while the other end is more round. Just make sure that all of the eggs are oriented round side up. By doing this, your foot will have a more level surface on which to stand.
- Remove your shoes and socks.
- Find a friend to assist you as you step up onto the first carton of eggs. The key is to make your foot as flat as possible in order to distribute your weight evenly across the tops of the eggs. If the ball of your foot is large, you might try positioning it between two rows of eggs instead of resting it on the top of an egg.
- When your foot is properly positioned, slowly shift all of your weight onto the egg-leg as you position your other foot on top of the second carton of eggs. There will be creaking sounds coming from the egg carton, but don’t get nervous.
Nails for Breakfast
Her morning bowl of cereal is a chance to learn about magnets and health.
- Box of iron-fortified breakfast cereal (Total® works well)
- Measuring cup
- Super strong magnet
- Quart-size zipper-lock bag
- Dinner plate
Instructions – Plastic Bag Variation:
- Open the box of cereal and pour a small pile of flakes on the plate. Crush them into tiny pieces with your fingers. Spread out the pile so it forms a single layer of crumbs on the plate. Bring the magnet close to the layer of crumbs (but don’t touch any) and see if you can get any of the pieces to move. Take your time. If you get a piece to move without touching it, that piece may contain some metallic iron.
- Firmly press the magnet directly onto the crumbs but don’t move it. Lift it up and look underneath to see if anything is clinging to the magnet. Several little pieces may be stuck there. Is it the magnet being attracted to static electricity or just sticky cereal? It could be the iron. Throw away the small pile of cereal and clean off the magnet.
- Pour water into the plate and float a few flakes on the surface. Hold the magnet close to (but not touching) a flake, and see if the flake moves toward the magnet. (The movement may be very slight, so be patient.) With practice, you can pull the flakes across the water, spin them, and even link them together in a chain. Hmmm… there must be something that’s responding to the magnet. Could it be metallic iron? In your cereal?
- Measure 1 cup of cereal (that’s equal to one serving according to the information on the side of the cereal box) into a quart-size zipper-lock bag. Fill the bag one-half full with warm water. Carefully seal the bag, leaving an air pocket inside.
- Mix the cereal and the water by squeezing and smooshing the bag until the contents become a brown, soupy mixture. Allow the mixture to sit for at least 20 minutes.
- Make sure the bag is tightly sealed and position it on a flat side in the palm of your hand. Place the super-strong magnet on top of the bag. Put your other hand on top of the magnet and flip the whole thing over so the magnet is underneath the bag. Slowly slosh the contents of the bag in a circular motion for 15 or 20 seconds. The idea is to attract any free moving bits of metallic iron in the cereal to the magnet.
- Use both hands again and flip the bag and magnet over so the magnet is on top. Gently squeeze the bag to lift the magnet a little above the cereal soup. Don’t move the magnet just yet. Look closely at the edges of the magnet where it’s touching the bag. You should be able to see tiny black specks on the inside of the bag around the edges of the magnet. That’s the iron!
- Keep one end of the magnet touching the bag and move it in little circles. As you do, the iron will gather into a bigger clump and be much easier to see. Few people have ever noticed iron in their food, so you can really impress your friends with this one. When you’re finished, simply pour the soup down the drain and rinse the bag.
Baby Diaper Secret
Help your school-aged kid learn all about polymers–and just what happens in baby sib’s diaper.
- Disposable diapers (several brands)
- Zipper-lock bag
- 8-ounce plastic cup
- Place a new, unused diaper on the piece of newspaper. Carefully cut through the inside lining and remove all the cotton-like material. Put all the stuffing material into a clean, zipper-lock bag.
- Scoop up any of the polymer that may have spilled onto the paper and pour it into the bag with the stuffing. Blow a little air into the bag to make it puff up like a pillow, then seal the bag.
- Shake the bag for a few minutes to remove the powdery polymer from the stuffing. Notice how much (or how little) powder falls to the bottom of the bag.
- Carefully remove the stuffing from the bag and check out the dry polymer you just extracted from the diaper.
- Pour the polymer into a plastic cup and fill the cup with water. Mix it with your finger until the mixture begins to thicken.
- Observe the gel that the polymer and water create. Turn the cup upside-down and see how it has solidified. Take it out and play with it. Amazing stuff!
- Put the pieces of gel back into the cup and smoosh them down with your fingers. Add a teaspoon of salt, stir it with a spoon and watch what happens. Salt messes up the gel’s water-holding abilities. When you’re finished, pour the salt water goo down the drain.
- Grab a new diaper and slowly pour about 1/4 cup of warm tap water into the center of the diaper. Hold the diaper over a large pan or sink and continue to add water, a little at a time, until it will hold no more. Keep track of how much water the diaper can absorb before it begins to leak.
Get your little scientist into safety goggles and learn about carbon dioxide together in two fun ways.
- Safety glasses
- Measuring cup and spoons
- Baking soda
- Reclosable bags (quart-size zipper-lock bags and snack size zipper-lock bags)
- Toilet paper
Instructions – Plastic Bag Variation:
- Start by putting on your safety glasses.
- Fill three quart-size zipper-lock bags with approximately 1 tablespoon of baking soda.
- Fill three snack-size zipper-lock bags with varying amounts of vinegar. For example, fill one bag with 60 mL (1/4 cup) of vinegar, the next bag with 80 mL (1/3 cup) of vinegar and the last bag with 120 mL (1/2 cup) of vinegar.
- Seal the vinegar bags and place them in the bags with the baking soda. When you seal the outside bags, make sure to remove as much of the air as possible.
- Put the bags on a table where it’s okay for things to get a little wet and messy (outside tables would be good).
- Punch the vinegar bags inside the baking soda bags to break them open and then shake the baking soda bags to make sure the substances mix.
- Make observations about how large each bag gets and how long it takes before you hear the giant POP!
Instructions – Toilet Paper Variation:
- Tear off a square of toilet paper.
- Place 1 tablespoon of baking soda in the middle of the toilet paper square.
- Twist or fold the toilet paper around the pile of baking soda making a small packet.
- It’s best to have someone help you with the next few steps. Open the quart-size zipper-lock bag and measure 1/4 cup of vinegar into the bag. Add 1/4 cup of warm water to the bag.
- Zip the bag closed, but not all the way. You want a small opening just large enough to sneak in the wrapped up baking soda.
- Move the experiment to the sink, or better yet, outside. Remember, it’s all about teamwork. Drop the baking soda bundle into the bag and quickly seal the bag closed. Place the bag on the ground (or in the sink if you’re indoors) and get out of the way. Watch closely as the bag begins to puff up until the sandwich bag pops.
Help your child find out what her morning glass of milk has to teach about molecules in a few easy steps.
- Milk (whole or 2%)
- Dinner plate
- Food coloring (red, yellow, green, blue)
- Dish-washing soap (Dawn brand works well)
- Cotton swabs
- Pour enough milk in the dinner plate to completely cover the bottom to the depth of about 1/4 inch. Allow the milk to settle.
- Add one drop of each of the four colors of food coloring—red, yellow, blue and green—to the milk. Keep the drops close together in the center of the plate of milk.
- Find a clean cotton swab for the next part of the experiment. Predict what will happen when you touch the tip of the cotton swab to the center of the milk. It’s important not to stir the mix. Just touch it with the tip of the cotton swab. Go ahead and try it, then observe what happens.
- Now place a drop of liquid dish soap on the other end of the cotton swab. Place the soapy end of the cotton swab back in the middle of the milk and hold it there for 10 to 15 seconds. Look at that burst of color!
- Add another drop of soap to the tip of the cotton swab and try it again. Experiment with placing the cotton swab at different places in the milk. Notice that the colors in the milk continue to move even when the cotton swab is removed.
Helmet Crash Test
This experiment is a great way for your child to learn about trials and creating a lab report.
- Bike helmet
- Ski helmet
- Skateboard helmet
- Toy football helmet
- 10 honeydew melons
- Measuring tape
Instructions – Plastic Bag Variation:
- Fit melons as snugly as you can into the helmets.
- Lay out the tarp and have an adult help you put up the ladder.
- Choose a step to drop the melons from. You must drop them all from the same height in the same way!! (I dropped all the melons in my first test from 10 feet and in the second test from 8 feet.)
- Climb the ladder carefully and drop the control melon (no helmet).
- Measure the amount of damage to the melon. Take a picture.
- Clean up the mess.
- Follow the same steps with each of the other four melons in the helmets. Hold on to the strap and drop the helmet straight down. Don’t throw the helmet—just let go of it.
- After each drop, measure your results and take pictures. Clean up between drops.
- Run the entire experiment again from a different height to see if you get the same results.
Mentos Diet Coke Geyser
Get outside for this messy experiment that teaches about gas molecules and surface tension.
- A roll or box of Mentos® mints
- 2-liter bottle of diet soda (diet or regular soda will work, but diet soda is not as sticky)
- Piece of paper
- This activity is probably best done outside in the middle of an abandoned field, or better yet, on a huge lawn.
- Carefully open the bottle of soda. Position the bottle on the ground so that it will not tip over.
- Unwrap the whole roll of Mentos. The goal is to drop all of the Mentos into the bottle of soda at the same time (which is trickier than it looks). Roll a piece of paper into a tube just big enough to hold the loose Mentos. You’ll want to be able to position the tube directly over the mouth of the bottle so that all of the candies drop into the bottle at the same time.
- Don’t drop them into the bottle just yet! Warn the spectators to stand back.
- It’s just like fireworks on the 4th of July.
If your child is learning about plants in school, this experiment can help him understand how plants take in water through their roots and stems to survive.
- 6 white carnations
- 6 plastic cups
- Food coloring (red, yellow, blue, and green)
- Knife (you’ll need an adult helper for this)
- Fill each cup half full with water.
- Add about 20-30 drops of food coloring to each cup of water. In this case, more food coloring is better!
- Have an adult trim the stem of each flower at an angle to create a fresh cut.
- Place one freshly cut white carnation in each of the cups of colored water. Save the remaining two carnations for the next step. Make some predictions: Which color will be soaked up first? How long will it take?
- This popular trick is called “Split Ends” and it requires some help from an adult. Have your adult helper use a sharp knife to slit the stem straight down the middle. Put each half of the stem into a cup of different colored water (try positioning the red and blue cups next to each other, for example). Make a few more predictions: Which color will be soaked up? Will the colors mix to make a new color? Just remember to keep the ends of the stem wet at all times and make fresh cuts on the ends.
- You’ll want to check back every few hours to see how things are progressing. It may take as long as 24 hours for the colored water to work its way up to the white petals. At the conclusion of your experiment, remember to examine the whole plant carefully including the stems, leaves, buds, and petals to find every trace of color.