It’s fun to make a rubber-band powered car from cardboard, straws, and wooden skewers!
-glue (a glue gun works best)
-a plastic straw
-a CD (or a compass)
-pipe cleaner (optional)
Hints: Parental supervision recommended for hot glue gun use.
Here’s what you’ll be building:
Rubber Band Car kitchenpantryscientist.com
What to do:
Wrap cardboard around a large spice bottle so you can see how it bends. Cut a piece of cardboard about 9 inches (22cm) long to wrap around the bottle. Trim off the excess cardboard and tape it to create a tube.
Trace a CD or use a compass to make 8 circles that are around 4 and 1/2 inches (12 cm) in diameter. Use a ruler to make a square around each circle and then diagonal lines to mark the center of each circle. Cut them out and glue two circles together until you have four wheels. Use skewers to poke holes through the center of each wheel.
Poke skewers through each end of the cardboard tube, about 1 and 1/2 inches (4 cm) from the end of each tube. Make sure that the skewers are parallel and that they line up when you look through the end of the tube.
Use a screwdriver to make the holes larger.
Cut 4 pieces off of a straw that are about 1/2 inch (1.5cm) long. Glue them to the outside of each hole in the tube. Use a skewer to help align them. The skewer should spin freely.
One at a time, put wheels on the skewers and glue the OUTSIDE of the wheel to the skewer. Make sure that the wheels are parallel to the car, and to each other as they dry. Cut off excess skewer.
Poke a skewer down the center of one end of the car, parallel to the wheels so that it’s sticking out about 1 inch (3 cm.) See image above.
Decorate the car!
Tie three thin rubber bands together and hook them over the skewer that’s sticking out. If you have a pipe cleaner or wire, hook it onto the other end of the rubber bands. Drop the rubber bands down through the center of the tube.
Grab the rubber bands from the end opposite where they are attached to the car. Remove the pipe cleaner hook and wind them around the skewer to create tension in the rubber bands. Wind them until they’re tight.
Set the car down and let the wheels start to spin to see what direction the car will go. When you’re ready, let go!
Measure how far the car traveled.
Enrichment: How can you make the car go faster or farther. Try using different kinds and numbers of rubber bands. How could you redesign the car to make it work better?
The Science Behind the Fun:
In this experiment, you use your body’s energy to twist rubber bands around the wooden skewer axle of a cardboard car. The energy is stored as elastic energy in the tightly-stretched rubber bands. When you let the car go, the rubber bands apply enough force on the axle to turn the wheels on the car and elastic energy is transformed into the energy of motion, which is called kinetic energy.
This fun art/science project lets you transfer plant pigments to cloth, creating beautiful prints of your favorite leaves and flowers. It’s especially great for fall, when there are so many colorful leaves around.
-Fresh leaves and flowers (Dry leaves won’t work.)
-A hard, smooth pounding surface, like a wooden cutting board or carving board
-Wax paper or plastic wrap
-Mallets or hammers
-Untextured cotton cloth, like a dishtowel. Heavy cloth works better than very thin cloth.
-*Alum and baking soda to treat cloth (This is optional. I don’t pre-treat my fabric, but the treatment step will help bond and preserve color, if you want to frame your prints. You can also buy fabric that’s pre-treated for dyeing.)
Safety tips: Protective eye wear is recommended. Young children should be supervised when using mallets and hammers.
What to do:
*If treating cloth: The day before you do the project, add 2 quarts water to a large pot. Add 1 Tb alum and 1 tsp baking soda to the water. Add the cotton and bring to a boil. Simmer for 2 hours, turn off heat and soak for at least two hours. Let fabric dry.
The next steps are the same, whether you’re using an untreated piece of cotton or treated cloth.
Take a walk to collect colorful leaves and flowers. Choose plants that can be flattened. Flowers with huge centers, like coneflowers don’t work as well, but petals may be removed and pounded.
Cover the pounding surface with waxed paper or plastic wrap.
Cut a piece of cloth that will fit on the pounding surface when folded in half. Iron the fold.
Open the cloth and lay it on the pounding surface. (See image above)
Fold the cloth over the plants and pound it with the hammer or mallet. If you’re using a hammer, pound more gently.
Pound until you can see the forms of the leaves through the fabric. As the pigment leaks through, you’ll see the outlines of what you’re smashing. Hint: Hammers work better than mallets for fall leaves. For juicy leaves and flowers, use a mallet or hammer gently.
Label the image with plant names, enhance it with paint or markers, or leave nature’s design to speak for itself.
The Science Behind the Fun:
Pigments are compounds that give things color, and many of them are found in nature. Flowers, leave, fruits and vegetables are full of brilliant pigments. In this experiment, we transfer plant pigments to cloth by bursting plant cells using pressure from a hammer or mallet.
The green pigment found in leaves is called chlorophyll. In the fall, many trees stop making chlorophyll, and the red, yellow and orange pigments inside the leaves become visible.
Although you create a mirror image of leaves and flowers, you’ll notice that the color may be more intense on one side of the print. A waxy covering called a cuticle covers leaves, and is sometimes thicker on the top than on the underside of the leaf. It may affect the transfer of pigment to the cloth, making it easy to see structures like veins on the leaf print.
What parts of the leaf can you identify in the print you created?
In less than two weeks, the kids and I will hit the road to venture into the path of totality of the August 21st total solar eclipse. We’re hoping for clear skies in St. Joseph, MO, so that we can stand under the moon-darkened sky and catch a glimpse of the Sun’s corona.
Pinhole Solar Viewer- Kitchen Science Lab for Kids (Quarry Books)
The Exploratorium in San Francisco has a fantastic Total Solar Eclipse 2017 app that you can download for more resources and to watch the eclipse live.
Here are some of the coolest things I learned about total solar eclipses from NASA’s website:
1: During a total eclipse, it’s possible to see bright stars and planets, even in the middle of the day. (I knew it would get dark, but that’s amazing!)
2. The Sun is 400 times wider than the Moon, but it’s 400 times farther away, so they appear to be the same size if you’re looking at them from Earth. That’s why the Moon can completely cover the sun. Scientists describe this by saying that they have the same angular size.
3. If you’re in the path of the total eclipse and place a large sheet of white paper on the ground, you may see dancing “shadow bands” moments before and after the eclipse, which are created by tiny slivers of sunlight passing through the currents of Earth’s atmosphere.
4. The temperature in areas of the Moon’s shadow will briefly drop as the Sun’s light is blocked.
5. The only popular song that refers directly to an actual solar eclipse is Carly Simon’s song “You’re so Vain.” (1970 total solar eclipse in Nova Scotia) (Around 3:05 in the song.)
6. Just before a total solar eclipse, you can see flashes of light called “Bailey’s Beads”around the edges of the dark circle of the Moon. They’re caused by sunlight flashing through canyons on the Moon’s surface.
Will you be watching? The next total solar eclipse won’t traverse the continental United States until April, 2024.
Gallium is a soft metal related to other metals in Group 13 of the periodic table, including aluminum. It doesn’t exist as a free element in nature, but can be purified from other metallic ores, like zinc. Each gallium atom has 31 protons in its nucleus, so its atomic number is 31.
You’ll find it around you in thermometers, semiconductors, and even some LED lights, and one property that makes it so cool is that it melts from solid to liquid at low temperatures (around 85.6 degrees F or 29.8 degrees C.) This makes it easy to play with the liquid metal simply by melting it in a glass of hot water, or in the palm of your hand.
You can see the crystal structure in the side of the gallium “Lego” we created in play dough! KitchenPantryScientist.com
*Not for small children! Wearing gloves and safety goggles is recommended when observing gallium. Although is is fairly safe, gallium will coat hands with a lead-like substance. (Wash with soap and water to remove.) Gallium can also damage other metals, so keep it away from jewelry, like rings. I always recommend doing your research, as well as checking out the MSDS (Material Data Safety Sheet) of a new substance before using it to know what precautions to take.
We ordered 99.99% pure gallium on Amazon. It arrived in plastic tubes,in crystal form, but by placing the tubes in hot tap water, it melted easily. Eye droppers work well for moving the melted metal around. I’d recommend using a rimmed paper plate to contain the mess.
Try imprinting a Lego or toy car in play dough and pouring the molten gallium into the imprint. When it solidifies, you’ll have a cast of the item you imprinted! (It takes a while.) Gallium coats glass to create mirrored surfaces, so you can pour some into a small jar and use it to coat the sides. If you leave some in a puddle on the bottom of an upside-down jar, you can watch crystals form.
I’ve been hearing about this science demonstration for years, and finally decided to try it! If you do it at home, kids should wear safety goggles or sunglasses to protect their eyes, and adults should pour the 3% hydrogen peroxide into the bottles.
a tray or cookie sheet
3% hydrogen peroxide (available at most pharmacies and discount stores)
liquid dish soap
dry yeast (2 packets)
empty 16 oz bottle
What to do:
1. Pour 1 cup hydrogen peroxide into an empty 16oz bottle. (A funnel helps!)
2. Add 2 Tbs. liquid dish soap to the bottle and mix well with the hydrogen peroxide.
3. Put 8 drops of food coloring into the bottle and swirl to mix.
4. Position the bottle on the tray.
5. Pour 2 packets of yeast into a paper cup and pinch the cup’s lip to make a pouring spout.
6. Quickly pour the yeast into the bottle, while swirling the liquid vigorously to mix well. The better you mix it, the better the experiment will work!
7. Set the bottle down on the tray before the foam emerges from the top.
8. Watch the chemical reaction between catalase in the yeast and the hydrogen peroxide create oxygen bubbles in the soap!
9. When the reactions has stopped, have an adult clean up the mess by pouring everything down the sink and rinsing the tray with water. (Normally kids should clean up, but for this one, I’d recommend an adult do it.)
The Science Behind the Fun:
Hydrogen Peroxide (H2O2) is a common household chemical that is often used to disinfect wounds and bleach hair. Certain chemicals can break it down into water (H2O) and Oxygen (O).
Dry yeast is a living fungus that produces a molecule called catalase. Catalase is very good at breaking down hydrogen peroxide quickly. When you add yeast to hydrogen peroxide that’s been mixed with liquid soap, the soap traps the oxygen and makes bubbles that push their way out of the bottle.
You may notice that the bottle feels warm. That’s because the chemical reaction produces heat and is called an exothermic reaction.
This experiment is so awesome that our balloon-popping dog Heidi had to get in on the action! Try it, and you’ll see how much fun it is to play with the forces of physics using a blow drier and a ping pong ball or balloon.
Newton’s third law tells us that for every action, there is an equal and opposite reaction. As the air pushes up on the ball, the ball pushes back down on the air. Other forces are at work too, as pressure differences in the air column help the ball stay in the middle of the air flow.
It’s fun to track the weather, and you can create some cool meteorology instruments using stuff you have around the house. Here’s a great post by NOAA (The National Oceanic and Atmospheric Association) on how to make your own weather station.
It’s also fun and easy to do this cool convection current experiment, using warm and cold water to explore how air moves in Earth’s atmosphere.
To see how cold fronts move under warm fronts, you’ll need ice cube trays, water, blue and red food coloring and a clear container.
Add water to an ice cube tray and add a few drops of blue food coloring to the water in each cube space. Freeze.
Fill a clear container with room temperature water.
Place one or two blue ice cube or two at one end of the container, and a few drops of red food coloring at the other end.
Observe what happens.
The Science Behind the Fun:
Cold water(blue) is more dense than warm water and forces warmer water (red) to move up and over it.
This is similar to the way warm air is forced up when it collides with masses of cold air in the atmosphere. Warm air carries energy, and when there’s lots of moisture in the air, these collisions often result in thunderstorms.
Homemade Spinner with Tie-Dye Edges (KitchenPantryScientist.com)
Make a super-cool spinning toy using skateboard bearings, super glue and a little physics. Customize your design with a marker tie-dyed shoelace.
Warning: Not for recommended for kids under 5. Use adult supervision for super glue, sharp points, rubbing alcohol and glue gun.
-4 skateboard bearings (available online or at skateboard stores)
-superglue or Krazy Glue
-a white shoelace
-permanent markers, like Sharpies
-rubbing alcohol (isopropanol)
-a glue gun
1. Use a sharp point to remove the cover from one of the bearings so that you can see the ball bearings inside. (See image above.)
2. Cut a piece of paper 6cm x 6cm and draw an X from corner to corner.
3. Center the bearing with the cover removed in the middle of the X. Then, center the other 3 bearings around the one in the middle so that they’re evenly spaced. You can use a ruler to check spacing. (See image below.)
4. Add a single drop of super glue to the junction between each bearing to connect them. If you add too much, the spinner will stick to the paper. *Be careful not to get any glue onto the moving parts of the bearings.
5. When the glue is dry, carefully turn the spinner over and place another drop of glue at each junction.
6. When the glue is dry, prop the spinner up on its side and add glue to the junctions on the sides. (See image below.) Repeat on each side.
7. While the spinner glue is drying, make dots of permanent marker on the shoelace. In a well-ventilated area, suspend the shoelace over a tray or colander and drip rubbing alcohol onto it to make the colors run together. (See image.) Let it dry completely.
8. Use the glue gun to attach the shoelace to the outside edges of the spinner. Fill in gaps between the lace and bearings with hot glue.
9. Spin away!
The Science Behind the Fun:
If you look closely at a skateboard bearing there are only a few ball bearings connecting the center and the outside part that spins. This means that there’s very little friction, or rubbing, between the parts. If you spin the toy around the center bearing, that bearing is called the axis of rotation.
The three bearings on the outside of the spinner provide the rotating mass that gives the toy a property called angular momentum, which keeps it spinning until the frictional force from the ball bearings in the center slows it down.
Pigments are molecules that give things color. The pigments in permanent markers are trapped in ink compounds that are insoluablein water, which means that they won’t dissolve in water. However, if you add a solvent, like rubbing alcohol, or isopropanol, to permanent markers, it dissolves the ink. As the alcohol moves through the cloth you are decorating, it carries the pigments along with it.