Parents are under a ridiculous amount pressure to make sure kids finish homework, practice for music lessons and make it to sporting events, among other things. I saw the photo below on Facebook yesterday, and then again in a post on an awesome science blog called “It’s OK to Be Smart . The poster is funny, but kind of sad if you love science. It inspired me to attempt to help fellow parents by compiling a list of some of my favorite simple experiments. Most of them use ingredients you have on hand and you can also find these experiments and more, like DNA extraction from strawberries, on my KidScience app.
Parents: Insist that kids take the reins on their science fair projects. Let them look through this list of experiments, and then sit down with them for five minutes and tell them to think about how you can take simple experiments like these to the next level by applying them to real life. (For example, how could you test whether soap or hand sanitizer removes more of the microbes you can grow on a homemade petri dish?) What might happen if you change the variables, like how much water you use, the temperature or even the materials used in the original experiment?
Kids: Here are a few ideas to get you started. Just click on the experiment name or the blue typeface to follow the link to instructions, photos and videos of the experiments. Choose one that you have the ingredients for and try it! You shouldn’t need help for most of these unless you have to boil something. Lots of them even have a video you can watch, if you’re not sure about one of the steps. My kids and I have tested them all and you can leave a comment here if you have any questions. Do more research into the science behind what you’re doing and think about how you could apply this experiment to something in real life.
Diffusion Experiment See how food coloring or other liquids diffuse through gelatin. You could even do this with yellow or orange jello if you don’t have plain. How can you change the rate of diffusion? Think about how the chemicals we add to water, put on our streets to melt ice, and spray on our lawns and crops can move into our soil, ground water, rivers, lakes and oceans.
Microbial Zoos Sample different surfaces with a cotton swab, or do a hand washing experiment, and grow the microbes on a homemade petri plate. (You’ll need some agar for this, so it may require a trip to the store.) Here’s a video on how to make the plates.
Vegetable Vampires See how plants take up water using the forces of physics. Does this experiment work better with some plants than others?
Oil Spill Experiment: See why oil is so hard to clean up. What works best to remove it from water and feathers?
Window Sprouts: Plant a bean in a plastic baggie with a damp paper towel to see how plants need only water and air to sprout roots and leaves. Here’s a short video demonstrating how to make a window garden.
Homemade Solar Oven: Using a pizza box, aluminum foil, plastic wrap, and newspaper, you can harness the sun’s energy to cook your own S’mores!
Carbon Dioxide and Ocean Acidity: See for yourself how the carbon dioxide in your own breath can make a water-based solution more acidic. It’s the same reason too much carbon dioxide in Earth’s atmosphere can be bad for our oceans.
Plant Transpiration: See how trees “sweat” in this survival science experiment.
Earthworm Experiment: Do you know what kind of earthworms are living in your back yard?
Composting: Be a composting detective. Bury some things in your back yard (away from power cables) and dig them up in a few months to see how they look. Composting reduces methane gas emissions (a greenhouse gas) from dumps.
Solar Water Purification: This project illustrates the greenhouse effect and is a fun “survival science” experiment. Requires hot sun and some patience!
Citizen Science: Don’t forget about all the real environmental research projects you can participate in through Citizen Science programs all around the world!
It’s been cold in Minnesota. The governor closed all the schools today in anticipation of a high temperature of around 15 below, and a low of close to 30 below in the Twin Cities. And it gets colder as you go North. This morning on Kare 11 Sunrise, we threw boiling water in the air, froze foaming soap, blew ice bubbles and experimented with bologna at 20 below to see why tongues stick to cold metal.
We did the boiling water experiment at the cabin a few weeks ago when it was a balmy 18 below. As you can see, the low viscosity of the water, and the fact that it’s about to evaporates causes most of it to instantly freeze into a snowy fog and a shower of tiny ice crystals.
Snow, ice, wrapping paper and free time are abundant over the holidays. Here are a few fun experiments to fill the hours between celebrations. Click on the experiment name for directions.
Holiday Window Gellies: Kids of all ages love making these from gelatin and food coloring!
Snow Science: Melt snow to see how much water and dirt it contains.
Magic Ice Experiment: Lift an ice cube from a glass of water using only a string and some salt.
Wrapping Paper Egg Drop: Have a contest to see who can engineer the best egg-protecting container from left-over boxes, wrappers and decorations.
Rock Candy: Grow your own sugar crystals on a stick. What happens if you add a little peppermint oil?
What happens when food coloring molecules move, or DIFFUSE through gelatin, the substance that makes jello jiggle?
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.
You can watch us making them on Kare11 Sunrise News by clicking here.
-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!
-a glass bottle, like a juice bottle, whose neck is a little smaller than a hard-boiled egg
-small or medium-sized hard-boiled eggs, peeled
-a long match or lighter
1. Decorate your bottle to look like a monster, with the mouth of the bottle on the mouth-end of the monster
2. Put one or two birthday candles in the wide end of a hard-boiled egg.
3. Light the candles and hold them under the inverted bottle to warm the air inside.
4. Hold your bottle upside down and put the candle end of the egg up into the bottle so it forms a seal. Continue to hold the egg until the candle goes out and the egg is “pushed” into the bottle by atmospheric pressure, which is the weight of the air pushing down on the egg.
The flame from the candle heats the air in the bottle. When the candle goes out from lack of oxygen, the remaining air in the bottle cools rapidly, decreasing the air pressure in the bottle and creating a partial vacuum. The outside air, whose atmospheric pressure is higher, pushes the egg into the bottle as it attempts to equalize the pressure inside of the bottle.
If you start today, you can grow gorgeously gruesome rock candy, dripping with sugary fake blood, in time for Halloween. (It takes a week or two to grow nice big crystals.)
This experiment requires adult supervision for boiling and handling the hot sugar syrup. Once it’s cooled down, kids can take over.
To make 12-15 sticks, you’ll need the following:
-2 and 1/2 cups white granulated sugar
- 1 cup water
-cake pop sticks or wooden skewers
-red food coloring
- Dip one end of cake-pop sticks or wooden skewers in water and then roll them in granulated white sugar. The sugar should cover 2-3 inches of the stick. Let them dry completely. These are the seeds for the sugar crystal growth.
- Boil 2 cups water and 5 cups sugar until sugar is dissolved as much as possible. It should look like syrup. Once it cools, this syrup is your supersaturated sugar solution.
- Let syrup sit until it is no longer hot and pour into a large glass jar or deep bowl.
- When syrup is completely cool, set the sugary end of the sugar-seeded cake pops or skewers into the syrup, evenly spaced in the jar. Cover loosely with plastic wrap and let them sit for about a week. Gently move the sticks around occasionally, so they don’t stick to each other and the crystals in the bottom of the glass. If the glass container gets too full of crystals, pour the syrup into a new container and move your stick into the cleaner syrup to grow more crystals.
- When the rock candy is done, pull them from the syrup and let them dry. Save the syrup.
- To serve, pour a few cm of your sugar syrup into the bottom of a pretty glass and add a few drops of red food coloring. Stir.
- Put your rock candy, handle side up, into the glass. Be sure to give your guests napkins, so they don’t drip “blood” all over the house!
How do Crystal Grow?
Like bricks in a wall, crystals are solids formed by a network of repeating patterns of molecules. Instead of the mortar that holds brick together, the atoms and molecules are connected by atomic bonds.
Crystals that share the same chemical composition can be big or small, but the molecules always come together to form the same shape. Table sugar, or sucrose, is made up of a molecule composed of two sugars, glucose and fructose. Crystals formed by sucrose are hexagonal (six-sided) prisms, slanted at the ends.
The crystals on your rock candy sticks grow from the “seeds” of the sugar you rolled on the stick before you put them in the syrup.
Plants love water as much as vampires love blood. Although they don’t have long thin fangs, they’ve developed a great system for pulling water up through their trunks and stems to their highest leaves using capillary action.
The kids and I demonstrated how to make them on Kare11 Sunrise news last week. Click here to watch.
Make a vegetable vampire and watch capillary action move colored water through the cabbage creature you created.
To make a leafy vampire, you’ll need:
-head of fresh napa cabbage
-2 large cups, jars or plasticware containers large enough to hold the base of ½ of your cabbage
-fruits and veggies to use as eyes and eyebrows on your monster
-rubber bands or string
First, fill your two containers ¾ of the way to the top with warm (not hot) water.
Add 10 or more drops of blue food coloring to one container and 10 or more drops of red food coloring to the other .
With a sharp knife, cut the cabbage in half vertically, from the bottom up, leaving the top 10cm or so intact, so the two pieces are still attached at the crown. If possible, try to cut down the middle of one of the big leaves.
Use rubber bands to secure the bottoms of each side of the cabbage and make a fresh cut at the bottom, a few cm up from the old cut.
Put one half of the base of your cabbage in the red water, and the other half in the blue water.
Decorate your two “vampires” with eyes and spooky eyebrows made from olives and peppers (or whatever you have in the refrigerator.) Secure the decorations with toothpick.
Keep an eye on your cabbage to see how much colored water it’s drinking. Your vegetable vampire will have to drink for 24-48 hours for the best results.
Plants survive by drawing nutrients dissolved in water up into their stems, stalks, trunks, branches and leaves.
Capillary action is the main force that allows the movement of water up into plants. In a narrow tube, on a surface that attracts water, the attraction between the surface and water, coupled with the attraction of the water molecules to each other, pulls water up. Plants are composed of huge numbers of tube-shaped cells that take advantage of these physical forces.
In this experiment, you can see colored water being taken up, via capillary action, into your cabbage.
Imagine how high the water in giant redwoods has to travel to reach the leaves at the top. In very tall trees, a process called transpiration helps the water overcome the forces of gravity. Here’s a transpiration experiment you can try at home.
Halloween Halloween brings out the kid in all of us, and there’s no better way to celebrate than with some ghoulish science experiments. Next week, I’ll be adding Vegetable Vampires and Zombie Candy to the lineup!
Here’s a list of our favorites. Just click on the name of the experiment to go to the instructions, see photos of what to do, and learn a little science. Most have links to videos or TV segments where I demonstrate how to do the experiments.
Shocking Machine Make an electrophorus and Leyden jar to shock your friends! Here’s how to do it. We demonstrated it on Kare11 last week!
Frankenworms Gummy worms soaked in baking soda and water come to “life” when you drop them into vinegar! Click here for directions and a video.
Goblin Goo (All you need is cornstarch and water. Here’s a video on how to make the goo. You can add a little food coloring to the water if you want, but it may stain your hands!)
Bag of Blood (If you have ziplock baggies, water, red food coloring and skewers, you can do this experiment!) Here’s the video.
Fizzy Balloon Monster Heads (After we made Goblin Goo, I demonstrated how to make Fizzy Balloon Monster heads. Click here to watch.)
Magic Potion (Bubbly, stinky Halloween fun: I made a short video on how to make magic potion. Click here to watch it.
Mad Scientist’s Green Slime (To see a TV segment where we made Mad Scientist’s Green Slime, click here!) Here’s another video.
Apple Mummies (Here’s a link to a TV segment where the kids and I demonstrated how to make Apple Mummies. Click here.)
Alien Monster Eggs (These make a great centerpiece for a Halloween party, when you’re done playing with them.) I demonstrated how to make them on Kare 11! Click here to watch the video.
Creepy Critter Slingshots Lob Marshmallow eyeballs and spiders at a pumpkin or another target in this fun physics experiment.
It’s hard to believe it’s already August. Other than reading, we don’t do much to fight summer brain drain at our house, but the end of summer is a great time to head to the back yard or driveway for some science experiments. They’re so much fun that kids won’t even realize they’re using their noggins! Just click on the experiment for how-to directions, photos and videos.
Hungry? Build a solar oven from a pizza box and bake s’mores.
Stand on eggs or throw them as hard as you can without breaking them. You can always clean up mistakes with your hose!
And no summer would be complete at our house without an epic marshmallow shooting competition. You’ll even learn some physics!
You’ll have a blast learning physics by making water rockets!
While NASA’s rockets use rocket fuel as their working mass, these rockets use water. As pressurized air forces the water out of your rocket, the rocket moves in the opposite direction, just like Newton’s Third Law says it will. “For every action, there is an equal and opposite reaction.”
Although these rockets lack fins, a payload and a nose cone, you can see from this NASA illustration that they’re very similar to real rockets. You can make a complicated launch pad like this, but we decided to make things easy.
For this experiment, you’ll need:
-an empty one or two liter bottle from a carbonated beverage
-a cork that has been cut in half and will fit in the mouth of your bottle (An adult should do this. I used a serrated knife.)
-a needle for inflating balls
-a bike or ball pump
-a cardboard box cut to hold the bottle at an angle pointing away from you. This is your launch pad.
Push the needle through the cork so that it pokes out of the other side. Use the hole from the corkscrew to make it easier.
Fill the bottle about 1/3 of the way full of water and insert the cork in the bottle.
Set the bottle in the cardboard box so that it’s pointing up, but away from you. See the photograph.
Attach the needle to the bike pump, stand behind the launch pad and start pumping air into the bottle. The air pressure will build in the bubble at the top of the rocket. When the pressure gets high enough, it will force the cork and water out of the bottle with lots of force, and as the water shoots down, the rocket will shoot up!
What happens if you add more water, or less water to your rocket?
Can you imagine riding a real rocket? Check out Astronaut Abby’s website to meet a girl who wants to ride a rocket some day and ask an astronaut on the International Space Station questions!