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ice cube necklace logo | Yellow Scope

 

STRING AN ICE NECKLACE!

drink | Yellow ScopeWith summer just around the corner, we're looking forward to enjoying icy drinks in the sun. Are you?

In this month's 20 Minute Lab,we'll make an ice cube necklace with just a few items from around the house!

You might think that to make an ice cube necklace, you could just lay a string in an ice cube tray, fill it with water, and then freeze it. Well, that would be one way to do it!

But we’re going to use science to add the string AFTER the ice cubes have frozen! How could that work? Not by tying a knot around each one…. We’ll attach the string to the ice cubes using the power of salt!

Ready? Let’s do science!

ice cube necklace supplies | Yellow Scope

What You'll Need

  • bowl
  • water
  • ice cubes (3-5)
  • fine table salt
  • piece of string or thread about 18 inches long

Let's Get Started!

  1. Fill your bowl with water - almost to the top.

  2. Add your ice cubes. (You'll notice they float in the water.)

  3. Arrange the ice cubes so they are close together or touching.

  4. ice cube string | Yellow ScopeLay the string over the top of each ice cube (lengthwise works best).

  5. Now pour some salt in a small bowl.

  6. Use your fingers to sprinkle the salt over the string on top of each ice cube. You’ll need to use about ½ teaspoon for each ice cube. (Note: Too much salt or too little salt can prevent the experiment from working, so you may need to experiment a bit to get the amount just right!)

  7. ice cube salt | Yellow ScopeLet the salt sit on top of string and ice for about 30 seconds.

  8. Now pick up the string from both ends and watch the ice cubes come along!

  9. Congratulations! You made an ice cube necklace!

 ice cube necklace vertical | Yellow Scope

WHAT'S GOING ON?

How did the string become attached to the ice cubes? It's all in the salt. Adding salt to water decreases its freezing point. Normally, water freezes at 32°F – or 0˚ Celcius– this this is called the freezing point.

But when salt is added, water no longer freezes at 32˚F - it doesn’t freeze until the temperature gets colder. The more salt mixed with water, the lower the freezing point!

ice cube necklace | Yellow Scope

In this experiment, when you added the salt to the string over the ice cubes, it melted that area of the ice cube, creating a little pool of water.

As the ice melted, the water diluted the salt, which made it less able to lower the freezing point. The freezing point increased, and the ice cube refroze. This time the water froze over the string, trapping the string in the ice cube. So, when you lifted the string out of the bowl, the ice cubes held on and came along!

icy roads | Yellow Scope

If you live in a place where you get a lot snow and ice in the winter, you have likely seen salt used in this way to keep the roads safe! Big trucks will spread salt on the roads to prevent water from freezing into ice. This helps prevent cars from slipping and sliding and make the roads safer!

 

Do you think anything else might lower the freezing point of water? Try some other things like sugar, pepper, or baking soda and see what happens!

SHARE WITH US!

Let us know how your experiments turned out! Share your photos and results with us on Facebook, Twitter, Instagram, or send us an email to info@yellow-scope.com. We love getting your messages!

For more exciting experiments, check out our Yellow Scope science kits on the Shop tab of our website!


naked egg logo | Yellow Scope

 

MAKE A NAKED EGG?!

boiled egg | Yellow ScopeWith Easter right around the corner, you may be boiling and dying eggs.

Have you ever eaten a hard-boiled egg? They're pretty delicious, and making a boiled egg is kind of a neat experiment in itself. When it's boiled, you can peel off the shell and the egg inside keeps its shape!

But did you know that you can make an egg shell disappear - while the egg inside keeps its shape - with no cooking involved?

In this week's 20 Minute Lab, we'll make a naked egg using a few things from around the house.

clock | YEllow ScopeBonus Experiment! We'll also go a bit further and change our naked egg's shape! We'll make it bigger and smaller by changing the solutions the eggs are soaked in. Remember though, these eggs aren't for eating - they would taste disgusting! Remember, we never eat our science experiments! ;)

Just an FYI: The hands-on time involved in these experiments is very short, but there's a lot of waiting time. Be prepared for the science to work its magic overnight while you sleep! 

What You'll Need

  • naked egg supplies | Yellow Scope2 small, wide-mouthed glasses
  • 2 eggs (fresh uncooked eggs in their shells)
  • about 4 cups white vinegar
  • 2 spoons
  • 2 cups water
  • food coloring (optional)
  • 2 cups corn syrup

Let's Get Started!

Naked Egg

  1. Place one egg in each glass. 
  2. eggs in vinegar | Yellow ScopePour the vinegar into each glass, making sure to cover the egg by about half an inch.
  3. To prevent the eggs from floating up, place a spoon over them. Note: You can cover the glasses to reduce the vinegar smell!
  4. Leave the glasses undisturbed for about 24 hours.
  5. Remove the eggs and rinse them under running water.
  6. Gently rub the eggs until the shell is completely gone. Be careful, the eggs will be slippery!
egg dissolved shell | Yellow Scope 

Troubleshooting:

If your egg's shell is still hard after 24 hours, you may need to leave it for another day...

WHAT'S GOING ON?

What do you see? Where did the shell go? Does your egg feel rubbery and bouncy? How did that happen?

egg bubbles | Yellow Scope

The shell of an egg is made of calcium carbonate. Vinegar contains acetic acid.

When the acetic acid in the vinegar comes in contact with the calcium carbonate in the egg shell, a chemical reaction happens, which dissolves the egg shell!

You might have noticed that bubbles formed around your egg after you poured in the vinegar. The chemical reaction produces carbon dioxide gas, which are the bubbles you see.

egg diagram | Yellow ScopeSo that explains why the shell disappeared, but what keeps the egg from oozing everywhere?

Just under the eggshell is another type of covering called a membrane. A membrane is sort of like a thin skin. The vinegar doesn't affect the membrane, so it remains intact and holds the egg together. Pretty cool, right?

BONUS EXPERIMENTS

Big Egg, Small Egg

  1. naked egg in water | Yellow Scope 20 Minute LabsPour the vinegar out of the glasses and rinse them out.
  2. Place one naked egg in each glass.
  3. Add water to one of the glasses so it just covers the egg. (You can also add some food coloring to this glass to keep track of which one is water.)
  4. To the other glass, add corn syrup. (Note: The egg will float, but don't worry, that's OK. The syrup is denser than the egg!)
  5. Leave the experiment for another 24 hours.
  6. Remove the two eggs and compare sizes. Which egg is bigger?
  7. For fun, pierce the big egg with a needle (over the sink) and watch a thin stream of liquid squirt out of the hole!
eggs in water and corn syrup | Yellow Scope 20 Minute Labs

WHAT'S GOING ON?

Did your egg in the water get big? Did your egg in the corn syrup get small?
Wow! Why did that happen?

semipermeable membrane | Yellow ScopeWell, first, let's talk about that skin-like membrane of the egg. This thin layer actually has tiny holes in it, which allow for certain things to move in or out. 

Picture a fence with holes in it. You might be able to push a tennis ball through, but a basketball wouldn't fit.


In a similar way, small water molecules can move through the egg's membrane, but the larger sugar molecules in the corn syrup cannot fit through the tiny holes. 

egg in water | Yellow ScopeThis helps explain why the egg in the plain water glass grew larger. The concentration of water is higher in the glass than inside the egg. This means that water molecules move from the glass through the membrane into the egg - making it bigger! 

In the corn syrup glass, the concentration of water is higher inside the egg than in the corn syrup. This means that the water molecules move out of the egg, through the membrane, into the corn syrup. And the egg shrinks!

egg size comparison | Yellow Scope 20 Minute Labs

SHARE WITH US!

Let us know how your experiments turned out! Share your photos and results with us on Facebook, Twitter, Instagram, or send us an email to info@yellow-scope.com. We love getting your messages!

For more exciting experiments, check out our Yellow Scope science kits on the Shop tab of our website!


balloon logo 20 minute labs | Yellow Scope

 

A BALLOON BLOWING ITSELF UP?

Blowing up balloons is a fun way to celebrate a party or just add color to a room! But what if you could make a balloon blow itself up - inside a bottle?! 

In this week's 20 Minute Lab we'll do just that by using a few things from around the house.

First, try just blowing up a balloon in a bottle yourself. Place the larger, closed-end of the balloon into the bottle and attach the open-end of the balloon to the mouth of the bottle (like in the photo).

Now try blowing up the balloon by breathing into it. You can't! The bottle's already full of air and there's no room for any more!

But you can cheat using science. All you have to do is create a pressure change inside the bottle. Ready to try? Let's collect some everyday items and get started!

balloon bottle supplies | 20 Minute LabsWhat You'll Need

  • 1 clear glass bottle with a narrow neck
  • 1 balloon (or more, as you may want to do this multiple times. New balloons work best!)
  • water
  • tablespoon
  • hot pads

Let's Get Started!

  1. Pour about a tablespoon of water into the bottle. 
  2. Place the bottle in the microwave and heat for 1 minute until the water boils.
    microwave 20 minute labs | Yellow ScopeNOTE: If your bottle is too tall for the microwave, you can set it tilted on its side in a microwave-safe bowl!
  3. Ask an adult to carefully remove the hot bottle using hot pads and then hold it steady for you on a table or counter.
  4. Quickly stretch the opening of the balloon over the mouth of the bottle. Keep the large end of the balloon pointing up and centered over the mouth.
  5. Watch what happens! (Check out the video below to see how the experiment worked for us!)

 

Troubleshooting:

ballon troubleshooting | Yellow ScopeIf your balloon doesn't get sucked into the bottle, you may not have heated it enough. Make sure the water is boiling. It can also take some time for the bottle to cool. We transferred ours outside so the winter air would cool the bottle faster!

If the balloon sticks to itself instead of getting pulled into the bottle, you may need to pull the larger end up to free it from itself.

WHAT'S GOING ON?

Here's what you likely saw:

At first, the balloon moved around a bit, then collapsed. Suddenly the balloon got sucked into the bottle and turned inside out! Then the balloon started to expand and inflate inside the bottle.

Wow! Why did that happen?

water phases | Yellow ScopeHeating the water in the microwave caused the water to boil. You probably remember that water changes form depending on temperature. When water freezes, it turns to ice; room temperature water is liquid; and when water boils it turn into a gas. This gas or steam is also called water vapor. 

As the water boiled and turned to vapor inside the bottle, its pressure increased. This increase in pressure pushed the air out of the bottle. At this point, you attached the balloon to the mouth of the bottle.

As the water in the bottle started to cool, the vapor turned back to a liquid. This lowered the pressure inside the bottle, making the air outside want to move into the bottle.

But the balloon was in the way! First, the air inside the balloon was sucked into the bottle. This created a vacuum and caused the balloon to collapse, get pulled into the bottle, and invert. Next, air from the room pushed into the inside-out balloon, stretching it out and inflating it! 

SHARE WITH US!

Let us know what you did. Share your photos and results with us on Facebook, Twitter, Instagram, or send us an email to info@yellow-scope.com. We love getting your messages!

For more exciting experiments, check out our Yellow Scope Science Kits on the Shop tab of our website!


20 minute labs snowman dough logo | Yellow Scope

 

MAKE AN INDOOR SNOWMAN!

snowman | Yellow ScopeEverybody loves building a snowman (or a snowwoman, or snowgirl)! But maybe there's no snow where you live, or maybe you just want to stay warm while still having fun with sculpting.

Well, this week's 20 Minute Lab is just for you!

We'll use common household items to make a miniature winter wonderland, decorated however you like. Then, we'll use a chemical reaction to "melt" our creations, as though spring were coming!

This experiment would be a great way to show the snowman Olaf, from the movie Frozen, what would happen if he got what he desperately wanted - to hang out in the sunshine - an idea with melting consequences!

There are TWO different recipes for making Snow Dough, for twice the experimental fun! 

conditioner | Yellow Scope 20 minute labsSnow Dough Experiment 1: Uses baking soda and hair conditioner. This recipe is a little more crumbly (less like real snow) but is less sticky than the soap recipe and has a smoother look.

dish soap  | Yellow Scope 20 minute labsSnow Dough Experiment 2: Uses baking soda, salt, and liquid dish soap. This recipe has the texture of real snow (makes that satisfying crunch in your hands), is slightly sticky and 'impressionable' (bumpy look), but the soap can make a lot of bubbles when reacting with vinegar!

SNOW DOUGH EXPERIMENT 1
What You'll Need

  • snow dough supplies 1 | Yellow Scope 20 minute labs3 cups baking soda
  • 1/2 cup white hair conditioner
  • 1-5 cups vinegar
  • tray or pan with high sides
  • bowl
  • measuring cup
  • glitter (optional)
  • decorations

NOTE: this recipe is a little more crumbly (less like real snow) but less sticky than the salt recipe and has a smoother look.

Let's Get Started!

  1. snow dough mix | Yellow Scope 20 minute labsMix the baking soda and conditioner in the bowl (you can do this by hand!)
  2. Optional: Add the glitter, and mix again.
  3. Transfer the snow to the tray.
  4. Shape your snowman and add decorations! (We used buttons for eyes, twist ties for the nose and mouth, yarn for a scarf, keys for arms, and a Christmas tree hat decoration)
  5. Play as long as you like!
  6. When you're ready to "melt" your creation, add some vinegar (a cup or so at a time) to the measuring cup and SLOWLY pour it over the "snow" (make sure it all stays in the tray to prevent spills!)

snowman 1 | Yellow Scope 20 minute labs

SNOW DOUGH EXPERIMENT 2
What You'll Need

  • snow dough supplies 2 | Yellow Scope 20 minute labs2 cups baking soda
  • 2 tablespoons salt
  • 1 teaspoon dish soap (blue dish soap gives a nice glacier-like color to the 'snow')
  • 1-5 cups vinegar
  • measuring spoons
  • tray or pan with high sides
  • bowl
  • measuring cup
  • decorations

NOTE: this recipe has the texture of real snow (makes that satisfying crunch in your hands) but is slightly sticky and 'impressionable' (bumpy looking), but the soap can make a lot of bubbles when reacting with vinegar!

Let's Get Started!

  1. snow dough mix 2 | Yellow Scope 20 minute labsMix the baking soda and salt in the bowl (you can do this by hand!).
  2. Add the liquid dish soap, mix again.
  3. Transfer the snow to the tray.
  4. Shape your snowman and add decorations! (We used buttons for eyes, twist ties for nose and mouth, yarn for a scarf, keys for arms, and a Christmas tree hat decoration)
  5. Play as long as you like!
  6. When you're ready to "melt" your creation, add some vinegar (a cup or so at a time) to the measuring cup and SLOWLY pour it over the "snow" (make sure it all stays in the tray to prevent spills!).

snowman | Yellow Scope 20  minute labs

CONCLUSION

What's going on?

What makes the snowpeople melt when you add the vinegar? Well, they're not actually melting.

melting snowman | Yellow Scope 20 minute labsUsually when we talk about melting, we mean that we added heat to something and we turned it from a solid to a liquid.

For example, when you take an ice cube out of the freezer, the room temperature is warmer than the freezer, so the ice cube melts into liquid water. Or when the sun comes out, it adds heat to a snowman and melts it into liquid water.

With our snow creatures, the vinegar reacts with the baking soda in a chemical reaction. When vinegar and baking soda react, carbon dioxide gas is formed. (To learn more about chemical reactions, check out our Foundation Chemistry kit!)

melting snowman 2 | Yellow Scope 20 minute labsThose fizzing bubbles you see (as your magical snowland melts) are thousands and thousands of carbon dioxide bubbles.

If you made the second version of snowman, you'll notice that the soap used in the baking soda mix makes even more bubbles (though they're very small!)

So you see, we're not really imitating the sun, because the sun melts snow with heat. Instead, we created a chemical reaction that looks like melting, but is actually turning baking soda and vinegar into water and gas!

SHARE WITH US!

Let us know what you did. Share your photos and results with us on Facebook, Twitter, Instagram, or send us an email to info@yellow-scope.com. We love getting your messages!

For more exciting experiments, check out our Yellow Scope Science Kits on the Shop tab of our website!


20 minute labs blood logo | Yellow Scope

 

MAKE ICKY, EDIBLE, FAKE BLOOD FOR HALLOWEEN!

halloween kids  | Yellow ScopeHalloween is just around the corner! Maybe you need some  fake blood for your vampire costume? Or maybe you just want to have fun doing some spooky science in your kitchen this weekend.  

In this month's 20 Minute Lab, we'll make costume blood using everyday items from your baking shelf! 

Did you know in old black and white movies that they used to use chocolate syrup for blood? But that won't do in our real world of color!

halloween icons | Yellow ScopeAlso, to make fake blood look real, the liquid needs to be thicker than just red-colored water.

In this experiment, we'll create thick, dark, realistic-looking blood. You'll have all the other trick-or-treaters in awe!

NOTE: If making fake blood is a bit too spooky for your little scientist, check out our Bubbling Brews Experiment!

WHAT YOU’LL NEEDfake blood supplies | Yellow Scope blog

  • 4 ounces water
  • 2 cups powdered sugar
  • 2 tablespoons cocoa powder
  • 0.1 ounces red food coloring (about a third of a typical bottle)
  • blender
  • tablespoon
  • measuring cup
  • clean up towel
  • optional: wooden spoon or spatula (for scraping down the sides of the blender)

NOTE: though this recipe is safe, edible, and can be cleaned up with soapy water, it may stain, so choose clothes that can get messy!

LET'S GET STARTED!

  1. blender | Yellow Scope blogPlace the water in the blender.
  2. Add the powdered sugar, then blend until thoroughly mixed. You may have to stop once or twice to scrape down any sugar that's stuck to the sides.
  3. Add the red food coloring and blend well.
  4. Add the cocoa powder and blend well. Again, scrape down the extra cocoa stuck to the sides.
  5. That's it! You've made a batch of blood!
  6. How you apply your blood will depend on what you need it for, but drizzling it from a spoon works great if you just want it to fall naturally on your skin like this:

fake blood on hand | Yellow Scope blog

CONCLUSION

What's going on?

water vs molasses | Yellow ScopeWhat makes this fluid different than just using colored water?

All liquids flow, but some flow faster than others. Viscosity is the property of a liquid that describes how fast or slow it will flow. Usually, the thicker the liquid, the more viscous it is and the slower it flows.

Water is NOT very viscous - it flows very well. Think about pouring water out of a bottle - it comes out pretty fast, doesn't it?

Molasses, on the other hand, is much more viscous than water. Molasses flows very slowly - you might even have to use a spoon to get it out of the jar. 

Blood has a viscosity in between water and molasses; it's not as viscous as molasses, but it's about four times more viscous than water. In addition to water, blood is made up of cells and proteins, which make it thicker and more viscous.

For our fake blood recipe, we started with water. To make it thicker, we added powdered sugar and cocoa to imitate the viscosity of real blood. Did you notice that the mixture got thicker when you added the sugar? The cocoa powder also helped to thicken the mixture. In addition, the cocoa powder added a brownish color to make it look more like real blood - which is quite a bit darker than just bright red food coloring!

SHARE WITH US!

Let us know what you did. Share your photos and results with us on Facebook, Twitter, Instagram, or send us an email to info@yellow-scope.com. We love getting your messages!

For more exciting experiments, check out our Yellow Scope Science Kits on the Shop tab of our website!


 

USING DENSITY TO MAKE A RAINBOW

rainbow | Yellow Scope blogIsn't it exciting to see a rainbow? The beautiful array of colors is a wonder - it may seem like magic, but we can understand rainbows through science!

Put simply, rainbows occur when white light from the sun bounces off raindrops at a particular angle and splits into all the colors we can see.

In this month's 20 Minute Lab, we'll make our own rainbows using common liquids from your kitchen! Instead of splitting light, we'll make our rainbows using density.

Like real rainbows, this one won't last forever, but it's sure neat while it does.

WHAT YOU’LL NEED

  • rainbow jar supplies | Yellow Scope blogsmall clear glass jar (we used a small mason jar)
  • honey (generic brands work fine)
  • light corn syrup
  • blue or green dish soap
  • canola or olive oil
  • different colors of food coloring
  • rubbing (isopropyl) alcohol (91% works best, but 70% will do - it's what we used)
  • a small bowl (or multiple bowls if you don't want to clean the same one out a few times during the experiment)
  • spoon
  • eye dropper
  • water

NOTE: the amount of each liquid you use will depend on your jar's size and how thick you want to make the rainbow stripes. For each liquid, you will want to use equal amounts, except for the oil - you will use double the amount. In the Yellow Scope lab, we used half a cup of each liquid and a full cup of oil. 

LET'S GET STARTED!

  1. rainbow jar pouring | Yellow Scope blogMaking sure not to touch the sides, pour the honey into the center of the jar. (If your honey is crystallized, you can scoop some into a small bowl and heat for 20 seconds in the microwave).
  2. Pour the corn syrup into a small bowl. Add 2 drops of red and 1-2 drops of blue food coloring. Stir to make the syrup purple.
  3. Gently pour the syrup into the jar on top of the honey. (Make sure to pour in the center of the jar, avoiding the sides.)
  4. Now add the dish soap, again avoiding touching the sides of the jar.
  5. Measure the water into a small bowl and add food coloring. If your dish soap was blue, make the water green by adding 2 drops each of yellow and blue coloring. If your dish soap was green, add 2 drops of blue coloring to make the water blue. Stir to mix.
  6. Again, gently add the colored water to the center of the jar.
  7. Now add twice the amount of oil to the jar. The bottom half of this layer will be the 'yellow' layer, and the top half will become the orange layer.
  8. Measure the rubbing alcohol into a small bowl and 3 drops of red food coloring. Stir to mix.
  9. Using the eye dropper, carefully add the rubbing alcohol to the jar. This time you want to squirt the alcohol down the side of the jar. This prevents the alcohol from mixing with the water layer.
  10. Being careful to keep the liquid still, hold your jar to the light and admire all the colors!

rainbow jar | Yellow Scope blog

CONCLUSION

What's going on?

lava lamp pour | Yellow Scope blogWhy don't all the different liquids just mix together instead of forming layers? Well, each liquid has a different density. The different liquids stack on top of each other, with the most dense on the bottom and the least dense on the top. 

Density refers to how much stuff can be packed in a given space. Scientists call the “stuff”, mass and the “space”, volume.

You might remember from last month's 20 Minute Lab, Lava Lamp in a Glass, that some molecules are larger than others. Some liquids are made up of small molecules that are packed tightly together (more dense), while other liquids are made of large molecules that are more spread out (less dense).

Liquids made up of smaller molecules, like water, are more dense and sink toward the bottom. Liquids made up of larger molecules like oil are less dense and don't sink as much. 


oil water molecules | Yellow Scope blog

 

 

     

     

    In this experiment, you poured the liquids into the jar in a specific order, from the most dense (honey) to least dense (rubbing alcohol). In this way, each new layer stacked on top of the layer below it. You could repeat the experiment and try adding the liquids in a different order to see what would happen!

    NOTE: If you used 70% rubbing alcohol (like we did), that means that the other 30% is water. This means that when you added the alcohol, some of it sunk into the oil (creating that orange layer), since water is denser than oil and wants to go underneath the oil layer!

    SHARE WITH US!

     

     

     

    Let us know what you did. Share your photos and results with us on Facebook, Twitter, Instagram, or send us an email to info@yellow-scope.com. We love getting your messages!

    For more exciting experiments, check out our Yellow Scope Science Kits on the Shop tab of our website!


    20 minute labs lava logo | Yellow Scope blog

     

    MAKE YOUR OWN LAVA LAMP!

    lava lamps | Yellow Scope blogHave you ever seen a lava lamp? They're basically an ongoing chemical reaction in a bottle! They were a big hit in the past, and people would buy them to add some fun light and a mesmerizing visual to their room. 

    In this month's 20 Minute Lab, we'll use some household items to make our own lava lamps!

    This experiment is great because it's fun day or night (with a little flashlight help), and you can use the 'lamp' over and over again!

    Note: make sure NOT to drink or taste your lava lamp - it's would taste gross and wouldn't be good for your body!

    WHAT YOU’LL NEED

    • lava lamp supplies | Yellow Scope blogSeveral tablets of Alka-Seltzer (generic brands are fine)
    • vegetable oil (about 2+ cups)
    • food coloring
    • drinking glass
    • measuring cup
    • water

    Optional:

    • tray (to catch spills)
    • flashlight | Yellow Scope bloglarge flashlight (for nighttime fun!)
    • chopstick (for experimenting with stirring)
    • extras of everything to make more than one lava lamp!

    LET'S GET STARTED

    1. lava lamp steps | Yellow Scop blogFirst, fill your measuring cup with 1/2 cup of water.
    2. Add about 20 drops of food coloring and stir. (Remember, you can mix colors by adding 10 drops of different colors or some other combination!)
    3. Fill your glass a bit over halfway up with oil.
    4. Add the colored water to your glass (watch it sink and separate!)
    5. Break one Alka-Seltzer tablet into three or four pieces.
    6. Drop one of the pieces into your glass and watch what happens!

     

    Optional:
    1. flashlight | Yellow Scope blogAt night (or in a dark room), place the glass on top of a wide flashlight that will stand on its own. (Or you can make your own creative setup - we cut a small hole out of cardboard, then placed the glass on top and a bike light underneath).
    2. Turn the lights off, then add your Alka-Seltzer tablet and watch the lit up effect!
     

     (Notice how you can just keep adding pieces of tablet to keep the lamp going!)

    CONCLUSION

    What's going on?

    lava lamp pour | Yellow Scope blogBefore you put your tablet in the mix, you poured the colored water into the oil. Did you notice how the water went straight to the bottom?

    Density

    That happened because water molecules are smaller than oil molecules, so they can pack more tightly together. This means that water is denser than oil.

    It's sort of like the difference between sand and marbles - sand (like water) is made up of tiny bits, and marbles (like oil) are made of big bits. And you know that you can pack more sand into an area than marbles!

    oil water molecules | Yellow Scope blogWater and Oil Don't Mix

    Water doesn't mix with oil because oil is made of 'hydrophobic', or water-fearing, molecules that want to keep away from water. The food coloring, on the other hand, mixes well with water and dissolves into it (notice how the oil stays the same color).

    fizz | Yellow Scope BlogChemical Reaction

    Alka-Seltzer has sodium bicarbonate and citric acid in it. When you put the tablet in water, a chemical reaction occurs: the sodium bicarbonate and citric acid molecules bump into each other, swap parts, and form new molecules. One of those new molecules is carbon dioxide. 

    The fizzing action is actually bubbles of carbon dioxide gas. The bubbles  rise to the top of the glass, and as they do, they attach to globules of colored water and bring them up to the top as well!

    Once they reach the top, the bubbles burst, leaving nothing to keep the dense blobs of water from sinking again.

    Keep experimenting!

    Try these variations to keep the fun going:
    • alka-seltzer tablet | Yellow Scope blogTry different sizes of the tablet - what happens with a whole tablet? What about with lots of small pieces at once?
    • What happens if you use more water in the glass than oil?

       

      SHARE WITH US!

       

       

       

      Let us know what you did. Share your photos and results with us on Facebook, Twitter, Instagram, or send us an email to info@yellow-scope.com. We love getting your messages!

      For more exciting experiments, check out our Yellow Scope Science Kits on the Shop tab of our website!

       


      20 minute lab | No Leak bag | Yellow Scope

       

      A PIERCED BAG THAT WON'T SPILL A DROP?

      Now here's a great trick and a fun way to keep cool in the summer!

      In this month's 20 Minute Lab, we'll use some household items to see how some forms of plastic are leak-resistant, even when you poke holes in it!

      The supplies for this experiment are very simple, and it's a great one for a sunny day. It'll go fast, but you can extend the fun by experimenting with different materials to see what happens.

      WHAT YOU’LL NEED

      • No Leak bag supplies | Yellow Scope bloga few round pencils (colored pencils are often round and work just fine! We happened to have double sided pencils, but that's not necessary)
      • pencil sharpener
      • plastic bag (a zip-lock style is easiest to handle)
      • water

      LET'S GET STARTED

       

        1. First, you'll want to stand over a sink or be outside in case there are any spills.
        2. sharpened pencils | Yellow Scope blogSharpen all the pencils so they have a good point on them.
        3. Fill the bag about half-way with water and seal it closed. Make sure there aren't any leaks to start!
        4. Now, if you're in a group, you might pause here. Add some fun anticipation by asking your friends what they think will happen when you pierce the bag. Make a hypothesis!
        5. Pierce the bag all the way through both sides with a pencil, leaving some of the pencil poking out on both sides. (Leave the pencil in the bag!)
        6. Observe what happens!
      poke the bag | Yellow Scope blog

       

      CONCLUSION

      What's going on?

      ldpe |Yellow Scope blogPlastic bags are made out of something called a polymer. A polymer is a type of molecular structure that is a chain of repeated units - like beads on a necklace. ('Poly' means 'many', so polymer means 'many' units.)

      Most bags are made of a particular polymer called low-density polyethylene (LDPE), which has a lot of branching atoms on its chains of polymers. This makes it very flexible.

      LDPE is a very common material because it is light, tough, leak resistant and inexpensive. Perfect for packing material and bags!

      no lead bag | Yellow Scope blogWhen the pencil was poked through the bag, the long flexible molecules formed a seal around the pencil, so the water didn't leak out!

      But if you try removing the pencils, the hole remains because the polymers were permanently squeezed aside by the pencil and can't return to the original shape. So when you're done, you can pull out the pencils to make a summer shower!

      leaking bag | Yellow Scope blog

      Keep experimenting!

      Try these variations to keep the fun going:

      • a different type of bag (produce, grocery carryout bags, sandwich bag, etc)
      • try different types of pencils - bigger ones, smaller ones, the kind with flat edges, etc.
      • try pens, skewers, or sticks

      What happens using these materials? What changes? What works best?

       

      SHARE WITH US!

       

       

       

      Let us know what you did. Share your photos and results with us on Facebook, Twitter, Instagram, or send us an email to info@yellow-scope.com. We love getting your messages!

      For more exciting experiments, check out our Yellow Scope Science Kits on the Shop tab of our website!

       


      elephant toothpaste logo | Yellow Scope blog

       

      MAKE TOOTHPASTE FIT FOR AN ELEPHANT!

      Have you ever seen an elephant at the zoo or in the movies? Did you notice those big tusks? Those are actually two very large teeth.

      Imagine if elephants had to brush those teeth? They'd need a very large tube of toothpaste!

      In this month's 20 Minute Lab, we'll be using some household items to produce an exothermic chemical reaction. The result is a fun oozing foam - big enough to use as elephant's toothpaste!

      The main ingredient for this experiment is hydrogen peroxide - a common first aid supply. The hydrogen peroxide in your cabinet is probably a 3% solution, which will work just fine for the experiment. If you want a more powerful reaction, you can use 12% hydrogen peroxide, which you can find at beauty supply stores. If you decide to try the 12%, make sure you ask an adult to handle it. The adult should wear gloves, since 12% hydrogen peroxide can irritate the skin.

      WHAT YOU’LL NEED

      • tray, plastic tub, or washable mat (You can use the one from your Foundation Chemistry kit if you have one!)
      • bottle with narrow neck
      • measuring cup
      • measuring spoons
      • hydrogen peroxide (standard 3% works, but 12% works even better)
      • food coloring (optional, but fun!)
      • dish soap
      • package of dry yeast (we used the measuring spoons, as we had bulk yeast)
      • water

      LET'S GET STARTED

      1. First, if you want to make it really seem like an elephant's toothpaste, you can cut a piece of paper to fit around your bottle and decorate it with markers or crayons to make it look like a toothpaste bottle! This isn't required for the experiment though, it's just for fun.
      2. Place your bottle on the mat or whatever you're using to catch the excess foam.
      3. Pour 1/2 cup of hydrogen peroxide into the bottle. (If you're using 12% hydrogen peroxide, have an adult do the pouring, perhaps using a funnel.)
      4. Add 8 drops of your favorite color food coloring.
      5. Add a good squirt of dish soap. Swirl to mix.
      6. Rinse out your measuring cup. Add 1 tablespoon of yeast and 3 tablespoons of warm water. Stir gently for about 15 seconds.
      7. Pour the yeast mixture into the bottle.
      8. Observe what happens!

       

      The red toothpaste was made using the standard 3% hydrogen peroxide.

      The blue toothpaste was made using 12% hydrogen peroxide! If you decide to use 12%, make sure to have an adult help and use gloves! (Note: We propped up the bottle a bit so the "toothpaste" squirted out to one side!)

      CONCLUSION

      What's going on?

      formulas | Yellow ScopeDid you make an oozing foam? Why did this happen?

      The chemical formula for hydrogen peroxide is H2O2. This means it is made up of two hydrogen atoms and two oxygen atoms. Can you see how similar hydrogen peroxide, H2O2, is to water, H2O?

      If you left a bottle of hydrogen peroxide open to the air, over time it would slowly break down into water (H2O) and oxygen (O2). The oxygen would be released as tiny bubbles of gas that would dissolve into the air.  Eventually you would just be left with a bottle of water - but this would take a long time!

      Adding yeast dramatically speeds up this process.bread | Yellow Scope blog This is because a package of yeast contains "catalase". Catalase is an enzyme that speeds up the breakdown of hydrogen peroxide into water and oxygen.

      Note: When something speeds up a reaction it's called a catalyst. There are lots of different types of catalysts, but this one's easy to remember: catalase the catalyst!

      soap bubbles | Yellow Scope blogIn our experiment, the dish soap traps the oxygen gas (O2), which creates lots and lots of bubbles! All this bubbling makes the substance quickly expand and shoot out of the bottle.

      You might notice that your bottle is now a bit warm! That's because this chemical reaction produces heat. This type of reaction is called an exothermic reaction ('exo' means outside or external and 'therm' means heat).

      At this point what's left in your bottle in just soap, water and oxygen, so you can pour the remains of your experiment safely down the sink!

      SHARE WITH US!

       

      Let us know what you did. Share your photos and results with us on Facebook, Twitter, Instagram, or send us an email to info@yellow-scope.com. We love getting your messages!

      For more exciting experiments, check out our Yellow Scope Science Kits on the Shop tab of our website!

       


      20 minute lab lemon logo | Yellow Scope blog

       

      USING LEMONS FOR INVISIBLE INK!

      Ever wanted to make a super secret message to a friend, like you were a spy in the movies?

      top secret | yellow scope blogIn this month's 20 Minute Lab, we'll be writing a message using the "ink" of a common fruit!

      Planning to set up a lemonade stand this summer with your friends or family? In between customers, you can use the lemonade to write secret messages to each other!

      If you don't have a lemon or lemonade, you can use bottled lemon juice, an orange, lime, other citrus fruit, or even vinegar!

      WHAT YOU’LL NEED

      egg supplies | Yellow Scope blog
      • half a lemon
      • small bowl
      • spoon and water
      • Q-tip
      • sheet of paper
      • a strong light bulb (100 watts), or an iron

      LET'S GET STARTED

      1. Squeeze about a tablespoon of lemon juice into the bowl.
      2. Add a teaspoon of water and mix with a spoon.
      3. Dip one end of the Q-tip into the lemon juice.
      4. lemon setup | Yellow Scope blogUsing the Q-tip like a pencil, write your message on the paper! (Note: Don't use too much lemon juice when writing each letter to avoid getting the paper too wet and warping it!)
      5. Depending on how long your message is, you may have to re-wet your Q-tip with lemon juice several times.
      6. Wait a few minutes for the paper to dry.
      7. light bulb | Yellow Scope blogNow hold your paper over the light bulb. (Note: incandescent bulbs work the best!) To use an iron, turn the steam setting to "off" and place a piece of fabric between the iron and paper. Have an adult help with this step!

       

       

       

       

      Troubleshooting

      If you could see your message after the paper dried - without applying any heat - you may have used too much lemon juice when writing. Try it again - this time letting the Q-tip rest on the edge of the bowl before writing to let some of the liquid drip off.

      If your message does not appear after applying heat, the heat from the light bulb may not be hot enough. Try using a hotter light bulb or try the iron method.

      CONCLUSION

      What's going on?

      Did your secret message magically appear? Did it turn dark brown? Why did this happen?

      Lemon juice is made up of carbon-based compounds, which you applied to the paper with the Q-tip. As you saw, it doesn't have any color at room temperature.

      However, heat breaks carbon bonds and sets some of those carbons free from the paper. When that free carbon contacts the oxygen in the air, it turns a brownish color. This process is called oxidation.

      lemon ink message | Yellow scope blog

      Sometimes substances will oxidize without any added heat. Have you ever had apple slices turn brown when they sit out for a while? That's because the carbon-based compounds in the apple oxidized without the need for the extra heat.

      apples | Yellow Scope BlogFun trick: to prevent your apples from turning brown, add some lemon juice to them! Lemon is a natural antioxidant which prevents the oxidation process from happening. 

      SHARE WITH US!

       

      Let us know what you did. Share your photos and results with us on Facebook, Twitter, Instagram, or send us an email to info@yellow-scope.com. We love getting your messages!

      For more exciting experiments, check out our Yellow Scope Science Kits on the Shop tab of our website!