Happy Saint Patrick’s Day! Yesterday, I demonstrated some fun rainbow science on The Jason Show. Click here to watch!
As part of the segment, I featured the “Rainbow Slime” experiment from my new book, “STEAM Lab for Kids,” which you can order from Amazon, Barnes and Noble, or your favorite online retailer. Here’s a sneak-peek at a few photos from the book.
Happy #womenshistory month! If you don’t know who Rachel Carson is, you should! Share her story with your kids and who knows? Maybe they’ll be the next Rachel Carson! (I included environmental science project ideas in the video.)
Under the right conditions, purified water can get much colder than 32 degrees before it freezes into a solid. This “supercooled” water will instantly freeze when it touches an ice crystal.
You don’t need a special lab to make supercooled water. In fact, you can make it in your own freezer!
1. Place three 12 oz bottles of water (caps loosened and re-tightened) in the freezer. Two should be filled with purified water and one with tap water.
2. Wait 2 hours and then check them every 5 minutes. When the tap water is frozen, gently remove the other two bottles from the freezer. (Tap water freezes first, because it contains some impurities that help ice crystals form more easily.)
3. Carefully open one bottle of purified water and pour it onto a few ice cubes on a plate. The supercooled water from the bottle will instantly crystallize into ice when it hits the cubes, making slush. Try it with the second bottle. There may be some freezing time variation between freezers, so you may have to experiment to find the perfect amount of time it takes your freezer to supercool water!
You can do the same thing by putting bottled water in a cooler full of ice, salt, and water. Salt lowers the melting temperature of ice, which makes the salty ice water cold enough to freeze bottles of liquid. Try the same experiment using soda to make a slushy! (From Outdoor Science Lab for Kids-Quarry Books 2014)
Grab your coat and head outside to try this fun winter science project!
A large plastic zipper bag
Cotton kitchen twine
a toothpick or wooden skewer
a spray bottle
a squeeze bottle or syringe (optional, but helpful)
a very cold day (below 10 degrees F works best, but you can try it on any day when it’s below freezing)
Note: This experiment takes lots of playing around and results will vary depending on how cold it is outside. Remind your kids (and yourself) to be patient and try it on a colder day if it doesn’t work the first time around! If the bag leaks too quickly, try making one with smaller holes around the string.
What to do:
- Use a toothpick or skewer to poke 3 small holes in the bottom of a zipper plastic bag. Make one in the middle and one on each end.
- Cut three long (3 feet or so) pieces of kitchen twine and knot them at one end.
- Carefully thread the twine through the holes in the bag so that the knots are inside the bag to keep the strings from falling through. Try to keep the holes from getting too big, since the bag will be filled with water and you’ll want it to drip out very slowly around the string.
4. Attach two more pieces of twine to each top corner of the bag (above the zipper) to use for hanging the bag
5. Go outside and hang the bag from a low tree branch or railing.
6. Tie each of the three strings to something on the ground, like a rock, piece of wood, or the handle of an empty milk carton filled with water to weight it down. Arrange the objects so that the strings loosely radiate out at around a 45 degree angle. (See photo)
7. Add food coloring to some ice-cold water in a pitcher.
8. Fill the spray bottle with ice-cold water.
9. Add the cold colorful water to the zipper bag hanging outside. Zip the top of the back to slow the rate of leaking.
10. Immediately spray the strings with water to guide the leaking water down the strings.
10. Wait for the water on the strings to freeze. Use your syringe to add a little bit more water to the strings (same color) and wait for them to freeze again. Repeat until you have a nice layer of ice/icicles.
11. Refill the bag, using a different color of ice-cold water. Spray the strings lightly again. Repeat step 11.
12. Add layers of color to the icicles until you’re happy with the way they look!
The science behind the fun:
Icicles form when dripping water starts to freeze. Scientists have discovered that the tips of icicles are the coldest part, so that water moving down icicles freezes onto the ends, forming the long spikes you’ve seen if you live in a cold climate. When you add different colors of water to icicles in sequence, the color you add last will freeze onto the tip of the ice.
You’ll find more fun ice science experiments in my book “Outdoor Science Lab for Kids” and in my upcoming books “STEAM Lab for Kids” (Quarry Books April 2018) and “Star Wars Maker Lab” (DK- July 2018)
Have you ever wondered why putting chemicals like salt on a road makes the ice melt?
To see how NaCl (table salt) melts ice by lowers the melting temperature of water, you’ll need an ice cube, a glass of water, and a piece of kitchen twine or string about 6 inches long and salt.
What to do:
Drop an ice cube in a glass of ice water. Try to pick the ice cube up without your fingers by simply placing the string on it and pulling up. Impossible, right?
Now, dip the string in water, lay it across the ice cube and sprinkle a generous amount of salt over the string/ice cube. Wait about a minute and try again to lift the cube using only the string. What happens?
It may seem like magic, but it’s only science. Here’s a video from my KidScience app where I demonstrate the experiment.
Salt lowers the temperature at which ice can melt and water can freeze. Usually, ice melts and water freezes at 32 degrees Farenheit, but if you add salt to it, ice will melt at a lower (colder) temperature.
The salt helps the ice surrounding the string start to melt, and it takes heat from the surrounding water, which then re-freezes around the string.
Different chemicals change the freezing point of water differently. Salt can thaw ice at 15 degrees F, but at 0 degrees F, it won’t do anything. Other de-icing chemicals they add to roads can work at much colder temperatures (down to 20 degrees below zero.) If it’s cold enough, even chemicals won’t melt the ice.
Pressure can also make ice melt at colder temperatures. This is why ice skates glide on rinks. The pressure is constantly melting the ice a where the blade presses down on it so the blade glides on a thin layer of water!
There are few gifts more fun than a homemade science kit. Give a kid a bottle of vinegar and a box of baking soda and you’ll make their day. Throw in a bottle of Diet Coke and some Mentos mints, and you may be their favorite person ever. Make a kit for your kids or grand kids. Make one for your favorite niece or nephew. Encourage kids to make kits for friends and siblings.
Here are some ideas for items to include in your kit.I’ve highlighted links to the experiments on my website (just click on the blue experiment name) in case you want to print out directions to add to your kit. You can also find these experiments on my Kitchen Pantry Scientist YouTube channel!
-composition book: Makes a great science notebook to draw, record, and tape photos of experiments into.
-clear plastic cups to use as test tubes and beakers
-measuring spoons and cups
-school glue (white or clear) for making Mad Scientist’s Slime
-contact lens solution for making Borax-free Slime
-gummy worms to transform into Frankenworms
-baking soda: Can be used for a number of experiments like fizzy balloons, magic potion . Or just mix with vinegar to make carbon dioxide bubbles.
-vinegar Great for fizzy balloons , alien monster eggs and magic potion.
-balloons for fizzy balloons.
-dry yeast for yeast balloons.
-white coffee filters: can be used for magic marker chromatography, in place of a paper bag for a coffee-filter volcano or making red cabbage litmus paper.
-cornstarch:Lets you play with Cornstarch Goo, a non-newtonian fluid. Here’s the video.
-marshmallows with rubber bands and prescription bottle rings you have around the house can be used to make marshmallow catapults. My kids used theirs to make their own Angry Birds game.
-Knox gelatin and beef bouillon cubes can be used to make petri plates for culturing microbes from around the house. You can also use the gelatin for cool osmosis experiments!
-food coloring Helps you learn about surface tension by making Tie Dye Milk. Here’s the video. You can also easily make colorful sugar-water gradients that illustrate liquid density!
-Mentos mints will make a Mentos geyser when combined with a 2L bottle of Diet Coke.
-drinking straws are great for NASA soda straw rockets and a carbon dioxide experiment.
To take it up a notch, throw in a copy of one of my book! You can find them on Amazon, Barnes and Noble and anywhere else books are sold!
Crying over broken candy canes? Cry no more. Make art!
My publisher recently sent me a copy of “Amazing (Mostly) Edible Science,” by Andrew Schloss. There are tons of fun experiments in the book, but Candy Cane Origami seemed like a perfect one to try during the holidays.
*Melted candy can get dangerously hot, so parental supervision is required!
-candy canes (broken or whole), wrappers removed
-heavy-duty aluminum foil
-a cookie sheet
-a wire cooling rack
What to do:
- Preheat oven to 250F.
- Cover cookie sheet with foil
- Place candy canes on foil, not touching each other
- Bake candy canes for around 10 minutes and have an adult check them. They should be stretchy, but not too hot to touch.
- When the candy canes are ready, bend, fold, twist and pull them into cool shapes. Try pulling one long and wrapping it around a chopstick to make a spiral. What else could you try?
- If the candy gets to brittle to work with, put it back in the oven for a few minutes to make it soft again.
The science behind the fun:
If you looks at the ingredients of candy canes, they’re usually made of table sugar (sucrose), corn syrup, flavoring, and food coloring. Glucose and fructose are sweet-tasting molecules that stick together to make up most of the sugars we eat, like table sugar (sucrose) and corn syrup. You can think of them as the building blocks of candy.
At room temperature, candy canes are hard and brittle, but adding heat changes the way the molecules behave. Both table sugar and corn syrup contain linked molecules of glucose and fructose, but corn syrup has much more fructose than glucose, and the fructose interferes with sugar crystal formation. According to Andrew Schloss, “the corn syrup has more fructose, which means the sugar crystals in the candy don’t fit tightly together. The crystals have space between them, which allows them to bend and move without cracking.”
Here’s a great article on the science of candy-making!
If you’re looking for holiday gifts for a science-loving kid, my books Kitchen Science Lab for Kids and Outdoor Science Lab for Kids include over 100 fun family-friendly experiments! They’re available wherever books are sold.
Gelatin is the substance that makes Jell-O jiggle. See what happens when food coloring molecules move, or DIFFUSE through Jell-O.
This creative science experiment that my kids and I invented lets you play with floatation physics by sprinkling glitter on melted gelatin, watch colorful dyes diffuse to create patterns and then use cookie cutters to punch out sticky window decorations. Water will evaporate from the gelatin, leaving you with paper-thin “stained glass” shapes.
-plain, unflavored gelatin from the grocery store or Target
–a drinking straw
*You can use the recipe below for two pans around 8×12 inches, or use large, rimmed cookie sheets for your gelatin. For a single pan, cut the recipe in half.
Step 1. Add 6 packs of plain, unflavored gelatin (1 oz or 28 gm) to 4 cups of boiling water. Stir well until all the gelatin has dissolved and remove bubbles with a spoon.
Step 2. Allow gelatin to cool to a kid-safe temperature. Pour the liquid gelatin into two large pans so it’s around 1-1.5 cm deep. It doesn’t have to be exact.
Step 5. In the pan with no glitter, use a straw to create holes in the gelatin, a few cm apart, scattered across the surface. It works best to poke a straw straight into the gelatin, but not all the way to the bottom. Spin the straw and remove it. Then, use a toothpick or skewer to pull out the gelatin plug you’ve created. This will leave a perfect hole for the food coloring. Very young children may need help.
Step 6. Add a drop of food coloring to each hole in the gelatin.
Step 7. Let the gelatin pans sit for 24 hours. Every so often, use a ruler to measure the circle of food coloring molecules as they diffuse (move) into the gelatin around them (read about diffusion at the bottom of this post.) How many cm per hour is the color diffusing? Do some colors diffuse faster than others? If you put one pan in the refrigerator and an identical one at room temperature, does the food coloring diffuse at the same rate?
Step 8. When the food coloring has made colorful circles in the gelatin, use cookie cutters to cut shapes from both pans of gelatin (glitter and food coloring), carefully remove them from the pan with a spatula or your fingers, and use them to decorate a window. (Ask a parent first, since some glitter may find its way to the floor!) Don’t get frustrated if they break, since you can stick them back together on the window.
Step 9. Observe your window jellies each day to see what happens when the water evaporates from the gelatin.
When they’re dry, peel them off the window. Are they thinner than when you started? Why? Can you re-hydrate them by soaking the dried shapes in water?
The Science Behind the Fun:
Imagine half a box filled with red balls and the other half filled with yellow ones. If you set the box on something that vibrates, the balls will move around randomly, until the red and yellow balls are evenly mixed up.
Scientists call this process, when molecules move from areas of high concentration, where there are lots of other similar molecules, to areas of low concentration, where there are fewer similar molecules DIFFUSION. When the molecules are evenly spread throughout the space, it is called EQUILIBRIUM.
Lots of things can affect how fast molecules diffuse, including temperature. When molecules are heated up, they vibrate faster and move around faster, which helps them reach equilibrium more quickly than they would if it were cold. Diffusion takes place in gases like air, liquids like water, and even solids (semiconductors for computers are made by diffusing elements into one another.)
Think about the way pollutants move from one place to another through air, water and even soil. Or consider how bacteria are able to take up the substances they need to thrive. Your body has to transfer oxygen, carbon dioxide and water by processes involving diffusion as well.
Why does glitter float on gelatin? An object’s density and it’s shape help determine its buoyancy, or whether it will float or sink. Density is an object’s mass (loosely defined as its weight) divided by its volume (how much space it takes up.) A famous scientist named Archimedes discovered that any floating object displaces its own weight of fluid. Boats have to be designed in shapes that will displace, or push, at least as much water as they weigh in order to float.
For example, a 100 pound block of metal won’t move much water out of the way, and sinks fast since it’s denser than water. However , a 100 pound block of metal reshaped into a boat pushes more water out of the way and will float if you design it well!
What is the shape of your glitter? Does it float or sink in the gelatin?
Here’s a video I made for KidScience app that demonstrates how to make window gellies
Credit: My 11 YO daughter came up with the brilliant idea to stick this experiment on windows. I was just going to dry out the gelatin shapes to make ornaments. Kids are often way more creative than adults!
Yesterday on Twin Cities Live, I demonstrated some fun botanical science projects for learners of all ages, including Vegetable Vampires and Leaf Chromatography.
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)
- Arrange leaves and flowers on the cloth.
- 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.
- When you’re finished pounding, unfold the fabric to reveal the print you created. Remove the leaves and petals.
- 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?
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.