Homemade Holiday Window Stickies (A Density, Diffusion, Evaporation Experiment)

 - by KitchenPantryScientist

I’m creating a fun new holiday experiment for 2014, but thought I’d re-post this experiment that my kids and I made up last year, since we love it so much. Try it!

What happens when food coloring molecules move, or DIFFUSE through gelatin, the substance that makes jello jiggle?

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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.

You’ll need

-plain, unflavored gelatin from the grocery store or Target

-food coloring

-a drinking straw

-water

-a ruler

-glitter

*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 3. Sprinkle glitter on the gelatin in one pan.  What happens?
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Step 4. Allow the gelatin to harden in both pans.

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.
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Step 6. Add a drop of food coloring to each hole in the gelatin.
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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.
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Step 9. Observe your window jellies each day to see what happens when the water evaporates from the gelatin.
IMG_3688When 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?
IMG_3691The 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!

Blundering Into Innovation

 - by KitchenPantryScientist

I was thrilled to see the words “In Praise of Failure” emblazoned across the New York Times Magazine innovation issue Sunday morning and to read stories that illustrate that there is no substitute for trial, error and risk-taking in the process of invention. It reminded me that I’ve been meaning to write about a fantastic kids’ science competition (Young Scientist Challenge) and an online kids’ show (Annedroids) that both embrace the idea that you have to make mistakes to create something great.

Two of the Young Scientist Challenge finalists talk about their Rube Goldberg machine.

Two of the Young Scientist Challenge finalists talk about their Rube Goldberg machine.

Each year, 3M teams up with Discovery Education to host an innovation competition called the Young Scientist Challenge. At the finals this year in St. Paul, ten smart, articulate kids presented original inventions they’d been working on all summer with 3M mentors. (Check out their videos on the website to see the amazing things they’ve invented!) The competition encourages kids to create innovations that address problems they see in the world around them, test their ideas using math and science, and present their projects, along with obstacles they faced along the way.

As one fun part of the competition, I got to watch the finalists frantically finish up Rube Goldberg machines they’d assembled from Legos, marbles, baking soda, vinegar, Mousetrap, and various other materials as teams. As judges looked on, some machines worked, and some marbles never made it into the mousetrap, but it was clear that process trumped perfection as the kids explained their ideas, the science behind them, and how they’d worked together to create their machines.

My kids are already looking forward to entering next year’s competition!

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The kid inventors on Annedroids (Amazon)

Kids get inspired in all kinds of ways, so I was thrilled when my 8YO switched things up from pink ponies to Amazon’s invention series Annedroids. I’m sure that she loves that  the main inventor is a girl, and as a science educator, the first episode had me at “we didn’t fail, we just discovered another way of doing it wrong.” The entire series is free if you have Amazon Prime, but the first episode is available at no cost everyone.

As for me,  I’ll be setting up a family holiday Rube Goldberg competition (and not just for the kids!)  We have Legos, baking soda, vinegar, and plenty of old toys in the basement, so I just need to pick up a Mousetrap game or two!

*Innovation Story: When 3M hired a young, banjo-playing engineering student named Richard Drew in 1920, they had no idea that he would revolutionize the entire company. At the time, 3M’s wildly popular new invention (and sole product) was abrasive particles stuck to paper with adhesive (sandpaper) and Drew’s job was to take samples to auto shops, where they could try it out on cars they were prepping to paint. Hanging around and observing the process of sanding and painting, Drew discovered that the tape they were using to do two-tone paint jobs was pulling fresh paint off the cars and decided to try to make a better tape. 3M gave him a lab and some materials, and he got to work experimenting, eventually introducing the world’s first roll of masking tape in 1925. As the company grew,  innovation continued to be an integral part of the culture, with every employee encouraged to spend 15% of their time working on their own projects. Now they make everything from the reflective material on street signs to multi-layer optical films and paper-thin microbial growth surfaces.

 

 

All About That Base

 - by KitchenPantryScientist

In addition to some of my neighborhood friends,two awesome chemist friends helped me out with this song: the amazing Dr. Raychelle Burks (with the Bronsted-Lowry line) and bassist Ryan Williams, who happens to have a PhD in Chemistry, with his awesome bass-playing.

The video quality isn’t top-notch, but you’ll get the idea, and hopefully learn a little chemistry!

Physics! Biology! Chemistry! Yeah!

 - by KitchenPantryScientist

I got together with some friends this weekend to do a quick iPhone recording of a chemistry song (on my Kitchen Pantry Scientist YouTube channel soon) and these awesome kids were nice enough take a break from playing to sing the Science Song with me. They had me laughing so hard that I could hardly get the words out!

Can you make up a song about science?

Candy Science: Icy Worm Pond

 - by KitchenPantryScientist

If you got any sour gummy worms for Halloween, they’re probably coated with sweet-sour powder made from citric acid  and sugar crystals. Using the same science used to make rock candy, you can use sour gummy worms to crystallize sugar syrup and make an”icy worm pond.” It’s even more fun to add sugar cubes to your pond! After a few days, you can chip your worms out of the “ice” to see how they taste. I created this experiment for Imperial Sugar and Dixie Crystals. Check it out on their website (click here) for directions and to learn more about the science behind the fun!

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If you don’t have sour worms, try coating other (non-chocolate) candy with sugar by dipping it in water, rolling it in sugar and letting it dry before you add it to your pond. It would be fun to do this experiment with Swedish fish, or lifesavers! 

Can you make up an experiment using Halloween Candy? Comment on this post with the experiment you created and you could win a copy of Kitchen Science Lab for Kids*!

*Winner will be chosen at random.

 

 

Halloween Science: Fizzy Balloon Monster Heads, Green Slime and More

 - by KitchenPantryScientist

With a few ingredients from your kitchen, you can turn your table into a mad scientist’s laboratory for Halloween! We made Fizzy Balloon Monster Heads, Alien Monster Eggs, Rock Candy and Soda Geysers on Fox9 News this morning. Click on the blue experiment names for directions!
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Last Saturday morning, I had fun showing Kare11 meteorologist Belinda Jensen how to make Mad Scientist’s Green Slime, Frankenworms and Magic Potion. Click here to watch!

Shoe Box Solar Viewer (for watching today’s partial solar eclipse)

 - by KitchenPantryScientist

There’s going to be a solar eclipse this afternoon, so I’m re-posting directions on how to make some simple solar viewers!

NEVER look directly at the sun, since you can permanently damage your retinas (the light sensors on the back of your eyeballs.)

Using a pinhole viewer, you can see the sun’s image with the sun behind you!

You can safety view the sun (and therefore a solar eclipse) using a shoe box by standing with the sun BEHIND you.  All you need is a shoe box without a lid, a piece of white paper, aluminum foil, a pin and tape. It’s perfect for viewing a solar eclipse, like the one coming up this afternoon. It will be visible from around 4:30 CST until 6:00 PM CST here in Minnesota!

A solar eclipse happens when the moon passes between the sun and the earth, blocking the sun from view.Go to this eclipse calculator to see when and where you can best view the eclipse with your viewer! Here in Minnesota, we’ll see a partial eclipse.

First, tape white paper over one end of the shoe box (on the inside.) This is your viewing screen.

Then, cut a big notch out of the other end of the shoe box and tape aluminum foil over it.

Use a pin to poke a hole in the center of the foil.  If you mess up, you can always put new foil on and try again. The smaller the hole, the better the focus, but we made ours a little bigger than the actual size of the pin.

Now, stand with the sun BEHIND you. (See photo at top of post. The sun is behind her, high in the sky.) NEVER LOOK AT THE SUN THROUGH THE PINHOLE ITSELF.

Hold the box upside down so the pinhole is pointed at the sun behind you.  The foil should be behind your line of sight so it’s not reflecting the sun in your eyes. Light rays from the sun will shine through the pinhole and project an (upside down) image on the white paper.

This was taken on a cloudy day when the sun peeked out, but you can clearly see the bright circle near the center of the paper.

Practice on a sunny day (or when the sun peeks out between the clouds) so that you know what to do when it’s time for the eclipse. Small children should be supervised so they don’t try to look directly at the sun.

You can do the same thing using two white index card, poking a hole in one you hold nearest to you and projecting the image on the one you hold away from you (with the sun behind you.)

If you’re interested in projecting a larger image of the sun, try making a solar viewer from  binoculars, a tripod and a white piece of paper. Click here for directions!

Enjoy! Watching an eclipse in the 70s after my dad came to school and helped us all make these boxes is one of my earliest “science” memories!

Halloween Soda Geysers

 - by KitchenPantryScientist

For an explosive fountain of Halloween fun, try this carbonated chemical reaction!

You’ll need:

-a two liter bottle of Diet Coke

-a roll of  Mentos mints

-a piece of paper.

-a disposable plastic table cloth or some construction paper

1. Make a Halloween costume for your Diet Coke bottle. We made pumpkins by cutting up a plastic tablecloth into sections and cutting a hole on the fold for the mouth of the bottle. Then, we draped the “costume” over the bottle and decorated it with permanent marker.

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2.Remove the lid from the bottle and set the Diet Coke on a flat surface (outside!)

3. Roll some paper so it will fit into the mouth of the bottle, tape it into a tube, and fill it with a roll of Mentos mints.

4. Quickly dump the mints into the bottle and stand back! (Young kids should wear safety goggles or sunglasses to protect their eyes.)

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The science behind the fun: Scientists are not sure exactly why the Mentos cause such an explosive reaction, but they think it has to do with the chemical reaction that occurs between the Diet Coke and the Mentos mints, when chemicals in the Mentos break the surface tension in the soda at the same time that carbon dioxide (CO2) bubbles form very rapidly on the surface of the mints, causing a huge, very fast release of carbon dioxide bubbles. The pressure of this gas builds very quickly in the bottle, shooting the liquid and bubbles into the air.

Halloween Science: Cornstarch Goblin Goo

 - by KitchenPantryScientist

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Mix a cup of cornstarch and around half a cup of water together for instant Halloween fun! Cornstarch and water mix together to form a strange concoction, called a shear-thickening fluid, that behaves like a solid when you agitate it, but behaves like a liquid when you let it sit still.

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To make your Goblin Goo more Halloween-y, add a drop of food coloring, but you’ll risk staining hands and other surfaces. You can experiment with adding more water or cornstarch to get your goo to the consistency of thick syrup.

The molecules in your mixture are sort of like long ropes.  When you leave them alone, or move them slowly, they can slide past each other.  However, if you squeeze them, stir them or roll them around in your hands, the ropey molecules look and feel more like a solid.  Materials like cornstarch goo are known as non-Newtonian fluids, since they don’t have the normal properties of  either a liquid or a solid.

Here’s a “watch and do” video for kids: