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20 Minute Labs geodes logo | Yellow Scope


geode | Yellow Scope blog

Have you ever seen a geode? On the outside, it looks like a plain old, round rock. But when you break it open, inside is a lining of beautiful crystals!

Geodes are found all over the world, usually in deserts. If you live in any of the southwest or midwestern states, you might be able to find them out in nature!

You can also find them for sale at toy and rock shops to take home and break open yourself.

Geodes start out as tree roots, mud balls, or volcanic bubbles inside of sedimentary rock. Over many millions of years, the outer, rounded shell hardens, but the inside remains hollow.

A liquid containing dissolved minerals gathers on the inner walls of the geode. Over time, these minerals form crystals!

geode | Yellow Scope blogIn this experiment, you can create some geode-like crystals using eggshells and a few items from home. The science is similar to how a real geode is made, but on a shorter time scale - 20 minutes instead of millions of years! 

NOTE: Setting up the lab will only take about 20 minutes, but once you're done you'll have to wait overnight to see the full results.


What You'll Need

  • egg geode supplies | Yellow Scope blog3 eggshell halves
  • measuring cup
  • 4 cups of water
  • pot
  • 1 3/4 cups borax
  • spoon
  • 3 glasses with lids
  • food coloring
WARNING: Be careful when working with borax. Work in a well-ventilated area; do not breath in the fumes and as with all science experiments - don't taste or eat anything! 

    Let's Get Started!

    1. eggshells | Yellow ScopeCollect eggshell halves. You can either hard-boil eggs and peel off the shells or crack open raw eggs and wash and dry the shells before using.
    2. With an adult's help, bring four cups of water to a boil in a pot on the stove.
    3. Remove the pot from the heat and SLOWLY stir in 1 3/4 cups borax until completely dissolved. (NOTE: Avoid splashing; do not inhale fumes; turn on air vent and/or open windows.)
    4. Let the solution cool for about 15 minutes.
    5. To each of the three glasses, add about 10 drops of food coloring. We found that lighter colors, like yellow, work well.
    6. egg geode in glasses | Yellow Scope blogCarefully pour  the borax solution into the three glasses so there is about the same amount in each one. The food coloring should easily go into solution. 
    7. Now add an eggshell to each glass, allowing it to sink to the bottom. Use a spoon to carefully arrange the shell so it isn't touching the sides of the glass to prevent sticking.
    8. Cover each glass with a lid. (This will prevent borax fumes from escaping.)
    9. Leave the glasses undisturbed overnight.
    10. The next day, carefully then scoop out the eggshell with a spoon. It will likely be stuck to the bottom of the glass, so you may have to use a bit of pressure to release it.
    11. Place on a plate or paper towel to dry. Enjoy your geode!

    egg geodes | Yellow Scope


    supersaturated solution diagram | Yellow ScopeYou probably noticed that the borax powder dissolved easily in the hot water. More borax will dissolve in hot water than in cold water. Hot water molecules move around a lot more and there is more space between the molecules. So there is more space to hold the borax. This type of solution is called a supersaturated solution. The water can not hold any more borax - it's completely stuffed!

    When the solution cooled overnight, the water molecules slowed down and got closer together. There was no more room for the borax, so it could no longer remain dissolved. The borax particles came out of solution and settled on the eggshells, in the form of crystals!

    What is a Crystal?

    When molecules like borax (a mineral salt) come together in a very organized, patterned way, a crystal is formed. The size and shape of the crystals depends on how fast the solution cools. When solutions cool fast, smaller crystals are formed because they have less time to organize. Slow-cooling solutions tend to form larger crystals. You might want to repeat the experiment again, but this time, try putting the glasses into the refrigerator overnight. What do you think will happen to the size of the crystals?  

    egg geodes | Yellow Scope


    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 We love getting your messages!

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


    ice cube necklace logo | Yellow Scope



    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


    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!


    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 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



    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 


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


    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?


    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


    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


    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 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



    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!)



    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.


    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! 


    Let us know what you did. Share your photos and results with us on Facebook, Twitter, Instagram, or send us an email to 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



    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!

    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

    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


    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!


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

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

    Gift Guide Title Image | Yellow Scope Gift Guide 2018

    Here’s a list of 15 science-themed gifts that have caught our eye this holiday season. From babies to tweens, there’s something for all the girls on your shopping list!

    We've added links for online shopping, but we also encourage you to shop local. Most of these gifts can be found at your favorite neighborhood toy or book shop!



    1. ABC What Can She Be? | Ages 2+
     ABC What Can She Be? | Yellow Scope Gift Guide 2018
    From astronaut to zoologist, this brightly illustrated board book will let her know that it’s never too early to dream big!
    $16.95 | your local bookstore
    2. Caterpillar Gears | Ages 18 months+
    Caterpillar Gears | Yellow Scope Gift Guide 2018
     Toddlers will love turning the interlocking gears to make the caterpillar crawl along the wooden board, all while building fine motor and problem-solving skills!
    3. Bathtub Ball Track | Ages 3+
    Bathtub ball track | Yellow Scope Gift Guide 2018
    Endless fun for bathtub engineers! Younger kids will love pouring water through the track to see what happens. Older kids will enjoy building and reconfiguring different courses to test with the ball.
    $19.99 |
    4. Wooden Bug Blocks | Ages 2+
    Bug blocks | Yellow Scope Gift Guide 2018
    We love all the high quality, made-in-the USA block sets in the Uncle Goose line, and the bug set is no exception. The budding entomologist in your life will love the detailed close-up illustrations and you will appreciate the thoughtful design.
    5. Quantum Physics for Babies | Ages 2+
    Quantum physics for babies | Yellow Scope Gift Guide 2018
    One in a series of board books written by physicist and father of four, Chris Ferrie, this book introduces basic concepts in physics to the very youngest of scientists, with a tongue-in-cheek style that adults will appreciate too!
    $9.99 | your local bookstore


    6. Magnetic Anatomy Puzzle | Ages 3+
    Anatomy puzzle | Yellow Scope Gift Guide 2018
    A great choice for the future anatomist or doctor on your list! This magnetic puzzle changes up the classic dress-up doll with 24 pieces, including internal organs, the skeleton, and the circulatory system.
    7. Cubetto Coding Toy | Ages 3+
    Cubetto Primo | Yellow Scope Gift Guide 2018
    Meet Cubetto, the friendly wooden robot! Kids will love learning the basics of computer programming through hands-on play. No screens or reading required.
    8. Bird Bingo | Ages 5+
    Bird bingo | Yellow Scope Gift Guide 2018
    For the littlest bird lover on your list, this beautifully illustrated set introduces 64 different bird species from around the world in a twist on the classic game.
    9. Binoculars | Age 3+
    Binoculars | Yellow Scope Gift Guide 2018 
    A perfect first set for the budding naturalist in your life, these shock-proof binoculars from Kidwinz are outfitted with high resolution optics. They even come with a protective carrying case for field work!
    $26.99 |
    10. Electro Dough Kit | Ages 4+
    Electro dough | Yellow Scope Gift Guide 2018
    Explore circuit making with electric dough. This fun set from Tech Will Save Us includes six pots of dough, along with buzzers, alligator clips, and LEDs to bring imaginary doughy creature to life!


    11. Paper Chromatography Kit | Ages 8+
    Chromatography kit | Yellow Scope Gift Guide 2018
    With Yellow Scope’s newest kit, kids will have a blast uncovering rainbows of color in plants, art supplies, candies and more using a super cool scientific technique. With art and creativity front-and-center, this kit will appeal to all kids, even those who may not realize they love science!
    12. Smore Magazine | Ages 7+
    Smore magazine | Yellow Scope Gift Guide 2018 
    Ignite her brilliance all year long with a subscription to Smore, a science magazine that encourages kids to know more and be more!
    From $29.99/year |
    13. Boolean Box | Ages 8+
    Boolean box | Yellow Scope Gift Guide 2018
    Created by Boolean Girl, a non-profit organization with a mission to close the gender gap in computer science, this kit teaches girls to build their own computer and learn to code using SCRATCH, Minecraft and Python.   
    $149.99 |
    14. Women of NASA | 10+
    Women of NASA | Yellow Scope Gift Guide 2018
    This 231-piece Lego set includes mini-figures of four pioneering women of NASA – astronomer Nancy Grace Roman, computer scientist Margaret Hamilton, and astronauts Sally Ride and Mae Jemison – along with instructions to build the Apollo Guidance Computer, the Hubble Space Telescope as well as the Space Shuttle Challenger.
     15. Cytosis Game | 10+
    Cytosis game | Yellow Scope Gift Guide 2018 
    Launched as a wildly popular Kickstarter project, Cytosis is a board game that takes place inside a human cell. Players compete to build hormones and enzymes all while fending off attacks by viruses!

    Yellow Scope | Five Empowering Halloween Costumes for Girls

    There’s nothing wrong with a princess costume - but some girls may want to trade their tiaras for a cape or beaker! It can be hard to find empowering costumes at your local Halloween pop-up, but the interest is there, and more girls are dressing up as strong female leaders.

    We’ve scoured the internet for inspiring costumes ideas and found many ready-to-wear and DIY costume options that are easy, unique and powerful!


    Yellow Scope Lab Coat | Empowering Halloween Costume For Girls | Scientist

    We’d be lying if we said we didn’t think everybody should dress up as a scientist at least once in their life, and Halloween is the perfect time. Yellow Scope’s white lab coat can be easily accessorized with a pair of safety goggles

    The lab coat includes a cute embroidered yellow microscope that reminds her of her awesome science powers and signals to others that a laboratory genius has entered the room.

    From now through October 31st, enter HALLOWEEN15 at checkout for 15% off anything from our website!


    Yellow Scope Empowering Halloween Costume for Girls | Olympic gymnast

    She was gliding across the kitchen floor in her socks during the Winter Olympics figure skating competition and she dreams of someday competing for TeamUSA. Award her with a gold medal costume this Halloween.

    Liz at Say Yes offers easy steps to create your own Olympic Gymnast costume which can be easily tailored to her favorite sport whether it’s basketball, tennis or skiing!  



    Yellow Scope Empowering Halloween Costume for Girls | Rockford Peaches

    Keeping with the sports theme, who doesn’t love A League of Their Own? Your daughter can celebrate her love for baseball by dressing up as a Rockford Peach.

    A Mighty Girl is an awesome online collection of smart and empowering books, movies, toys and more. Their Rockford Peach costume is officially licensed and features many of the same details seen in the movie including league patches, belt, dress, and baseball cap. Complete the costume with her favorite worn-in baseball glove.



    Yellow Scope Empowering Halloween Costume for Girls | Supergirl

    Leaping typical costumes in a single bound, your daughter will be well on her way to being a girl of steel in this Supergirl costume by Chasing Fireflys.

    The costume is comfortable and made of high-quality materials and includes a sparkly dress, cape and a strong gold belt. You can also purchase cool matching boots to complete the look.



    Yellow Scope Empowering Halloween Costume for Girls  |  Rosie the Riveter

    Our WWII heroine, Rosie the Riveter, is one of the most popular and beloved Halloween costumes for powerful girls and it can be easy to put together at home with a pair of denim pants and jacket. If you need a little help you can purchase the denim shirt, embroidered "Rosie" patch, and handmade polka dot headband from The Silver Closet on Etsy.

    There are lots of people pulling out their sewing machines to create exciting new costumes every day. This “Empowering Girl’s Costume” Pinterest board has lots of great ideas like Lt. Judy Hopps, Alice Paul, an astronaut or an arctic hunter. We hope these ideas inspire you to discover your favorite female role model. Share your costume creations with us on our Facebook page.

    Candy corn and moonlight - wishing you a happy Halloween night! 


    Let us know how your costumes turned out. Share your photos  with us on Facebook, Twitter, Instagram, or send us an email to We love getting your messages!

    Team Yellow Scope!

    20 minute labs blood logo | Yellow Scope



    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!


    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


    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!


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

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



    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.


    • 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. 


    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


    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!





      Let us know what you did. Share your photos and results with us on Facebook, Twitter, Instagram, or send us an email to 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



      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!


      • 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


      • 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!


      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!


      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!)


      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?


      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?


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

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


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