The Giant Dry Ice Bubble Sphere
If you’ve got some dry ice, why not gather friends and family and try your hand at making a large dry ice ghost bubble?This is especially fun at Halloween. Who knows? Maybe you will see your future inside the Ghostly Sphere.
YOU WILL NEED:
- Medium size bowl with a rim
- Small bowl
- Liquid soap
- 20 inch by 2 inch strip of absorbent cloth (cut up t-shirts work great)
- Warm Water
- Dry Ice – Available at some grocery stores and ice suppliers
CAUTION!: NEVER touch dry ice with your bare hands.
Always wear thick gloves and keep away from children.
NEVER place dry ice in a completely enclosed container.
WHAT TO DO:
Fill each bowl halfway with water. In the small bowl, add a good squirt of liquid soap (we like Dawn Concentrate) and stir it up.
Get the rim of the larger bowl wet with regular water using your fingers.
Add the dry ice to the large bowl. Admire the sights and sounds of bubbling dry ice.Now the tricky part, dip the cloth into the soapy water to get it wet but not dripping wet. Pull the cloth strip so that it is taut and pass it across the entire rim of the medium bowl to create a soap bubble “skin” over the bowl. It may take several tries – don’t give up!
Don’t worry about your bubble popping. We think that’s the coolest part!
CLICK HERE FOR MORE FUN HALLOWEEN EXPERIMENT IDEAS!
Make Some Ghost Bubbles!
If you want to make any day better, perhaps the easiest way is to add bubbles to it. We have seen lots of different kinds of bubbles: big bubbles, small bubbles, bubbles that don’t pop, even colored bubbles. But my personal favorite is Ghost Bubbles. They’re not that hard to make and they are great fun to explore…especially at Halloween:
YOU WILL NEED:
- A large plastic container with a wide mouth
- A rubber sink sprayer designed to attach to a faucet with the sprayer cut off/removed. (regular wide tubing, 1 cm or wider will work as well)
- Small bowl of bubble solution. CLICK HERE for a recipe.
- Warm Water
- Dry Ice – Available at some grocery stores and ice suppliers
- A glove made of fuzzy fibers.
CAUTION!: NEVER touch dry ice with your bare hands.
Always wear thick gloves and keep away from children.
NEVER place dry ice in a completely enclosed container.
WHAT TO DO:
- Carefully drill a hole towards the top of the container that is just wide enough to fit the tube.
- Fit the tube into the opening with the wide (faucet end) out as shown in the top picture and secure with tape if needed.
- Fill the container with warm water about 1/4 full.
- Drop several pieces of dry ice into the water and cap the container loosely. Dry ice mist should now be coming out of the tube.
- Dip the end of the tube into the bubble solution and make ghost bubbles! If the mist is coming out too fast, loosen the container cap to adjust the flow.
MORE GHOST BUBBLE FUN:
- Try holding Ghost Bubbles with a fuzzy glove such as a wool glove. With some practice, you can toss and bounce the bubble.
- Allow the bubbles to fall onto a fuzzy surface, such as a towel. Try rolling them around by lifting different ends of the towel. Fuzzy surfaces keep the bubble from easily popping because they spread out the amount of pressure on the surface of the bubble, and keep it from touching a surface that would absorb the moisture and dry out the bubble, causing it to pop.
GHOST BUBBLE INFO:
Every soap bubble is made of a film that has 3 layers: Soap, then Water, then Soap. Because of the way that soap molecules are arranged, and the way they attract and repel from each other and the water, the soap creates bonds that give the water additional strength, and allow them to last much longer. The dry ice mist is a combination of water vapor and carbon dioxide gas from the dry ice. Because carbon dioxide is heavier than air, dry ice mist will always flow downward.
CLICK HERE FOR MORE FUN HALLOWEEN EXPERIMENT IDEAS!
The Ultimate Bubble Solution
Bubbles may very well be the world’s first toy. From sea foam, to hand soap, to those bubbles you blow in your milk, it seems bubbles are part of our daily life. Soap bubbles way be the most fun off all bubbles and they are an inexpensive and limitless way to explore our bubbly world.
For years bubbleologists have perfected the solution for the longest-lasting and most durable bubbles. Perhaps the person who has studied the science of bubbles the most, is Keith Michael Johnson. And he recently shared his unlikely TOP-SECRET formula for the best bubble solution…
You will need:
- Water – many bubble enthusiasts are convinced that distilled water makes the best bubbles
- Liquid dish soap. Dawn dish soap has always been a favorite
- SurgiLube (available at medical supply stores) or K-Y Jelly (available at pharmacies)
- A clean plastic bottle to hold your bubble solution
What to do:
Simply pour all three ingredients into the bottle in the following ratio:
- 12 parts water
- 1 part dish soap
- 1/2 part SurgiLube
For example you would start with 12 ounces of water, add 1 ounce of liquid dish soap, and 1/2 ounce of SurgiLube. You can increase the amounts equally to make more.
- Shake the ingredients up well (don’t worry, the bubbles from shaking will go away)
- For best results, allow the bubble solution to sit overnight. Then you’re ready to go!
How do bubbles work?
Every soap bubble is made of a film that has 3 layers: Soap, then Water, then Soap. Because of the way that soap molecules are arranged, and the way they attract and repel from each other and the water, the soap creates bonds that give the water additional strength, and allow them them to last much longer. Bubbles will always be round when they are floating because the elastic nature of the soap bubbles allows air pressure to push equally on the entire surface of the bubble forming a sphere.
Bubble fun:
- You do not need bubble wands from the store to make bubbles. Simply dipping your hand in bubble solution and making a circle with your fingers makes a great bubble wand. Straws, plastic strawberry containers, fly swatters, and aquarium nets make great bubble wands.
- To make foamy bubbles, use a rubber band to secure a piece on cotton cloth over the end of a small section of plastic pipe. Soak the cloth in the bubble solution and blow from the other end.
- Pour a small amount of bubble solution onto a clean counter top and spread it out. Use a straw to blow a dome-bubble on the counter top. Keep blowing into the bubble to make it bigger and bigger. With some practice, you can get a bubble dome as big as a dinner plate!
Oreo Cookie Moon Phases
I’ve always been a fan of science activities that you can eat. One of my favorites that I have been using for years is the Oreo Cookie Moon Phases activity. It’s almost as if Oreo cookies were made for this lesson, and it’s a great way to see how well students can match a moon phase name with a moon phase appearance.
You will need:
- An Oreo cookie for each student
- A piece of paper with a moon phase written on it for each student (I omit “Full moon” – that’s just too easy)
- A popsicle stick or other tool for scraping the frosting
What to do:
- Fold up each piece of paper with the moon phases written on it and hand one to each student as they enter the room – tell them not to open it yet. I will often have them store it in their shoe. They think that’s funny, and they won’t lose it.
- Demonstrate the proper way to slowly twist an Oreo to maximize the amount of frosting on one side when you separate the halves. (practice yourself, it can be tricky)
- Give each student a cookie and have them twist the halves open. Hopefully most will the frosting will be on one side or the other. They can always transfer frosting if needed.
- Have the student retrieve their moon phases while you hand out the craft sticks.
- Recreate the given phase in frosting!
I will usually tour the room and once they show me that they’ve got the phase right, they can eat the moon! Of course be aware of food allergies and such. If you try this out, let me know how it goes!
A Density Experiment You Can Drink!
Density is a fascinating and sometimes tricky idea to understand. This Drink of Density will help bring home the idea of density in liquids, not to mention it looks cool when your all done, it’s tasty, and it’s even good for you – what more could you ask for in a science activity!
You will need:
- Juices that have different density levels. (see below for a simple explanation of density) The density of a juice is often determined by how much sugar or fruit is in it – the more sugar or fruit, the more dense the juice is. Powdered and canned juices do not work well for this experiment since they are almost entirely water. You will have to do some experimentation to find juices that are colorful and give a nice display of density, and that’s half the fun.
- A narrow glass (the more narrow it is, the easier it is to separate the density levels)
- Eye dropper or turkey type baster.
What to do:
- Before you begin, you can guess which juices you think will be more dense and form a hypothesis of how the levels of your Drink of Density will turn out. Check the number of ingredients, the sugar content, and the water content to help you out.
- In order to display your density levels, you will need to find out which of your juices are the most and least dense. Pour one of your juices into the narrow glass to fill it about 1 inch (2.5 cm) high. Fill a dropper with another juice and slowly drop it onto the inside of the glass so that it runs down the side of the glass. Watch the juice to see if it goes below or above the juice in there. (if it simply mixes with the juice and does not go above or below, it has the same density as the juice and you will need to move on to your next juice.
- Continue experimenting with other juices to determine which juices go to the bottom (more dense) and which ones go to the top (least dense.)
- Once you have the densities determined, start over with a clean glass and use the dropper for each level to create your final Drink of Density!
Note: In case you were wondering, the juices in the photo are (top) Tropicana Pomegranate-Blueberry, (middle) Tropicana Pure Premium Orange Juice, (bottom) Nature’s Promise White Grape (33 grams of sugar in 6.75 ounces!)
How Does It Work?:
The density of liquids demonstrates the the amount of “stuff” (atoms, mass) that are present in a particular volume of the juice. In other words, if you have cup with 200ml of plain water, and a cup with 200 ml of water that has lots of sugar dissolved in it, the cup of sugar water will be heavier even though they are the same volume of liquid – the invisible sugar molecules are dispersed in the water, making it heavier (more dense.)
Purple Brew: An Acid-Base Indicator
Next time kids say they don’t like vegetables, try out an experiment that will bring out the fun side of our leafy friends. Mom and Kiddo of the blog What Did We Do All Day? shows us how to play with color in this demonstration that uses an acid, a base, and a vegetable. She suggests keeping some of the solution in the fridge for a rainy day and allowing kids to experiment on their own.
You will need:
- purple or red cabbage
- small and large glass jars
- baking soda
- water
- vinegar
- measuring cup
- 1/4 teaspoon
What to do?
- Chop up a cabbage and simmer on the stove for 20 minutes to make a cool purple liquid (kids, please let a grown-up do this)
- After the purple brew has cooled, collect some small and large jars. Place about 1/4 tsp baking soda and 1/4 tsp water in one jar, a small amount of vinegar in another and about 1/4 cup purple brew in a third.
- Put some of the brew in a measuring cup and pour 1/4 tsp of the brew in each of the first small jars. What happens when you mix the purple brew with the different solutions?
- In the jar filled with a 1/4 cup of purple brew, pour about 1/4 cup vinegar. What happens?
- Next, add 1/4 tsp baking soda to the same solution. What is your observation?
How does it work?
Red cabbage contains a chemical called flavin and flavin has the ability to change color based on the pH level of certain liquids. Nuetral solutions, (like water) are purple. Acid solutions, like the vinegar, turn will turn flavin red. Basic solutions, like the baking soda water, become blue.
You can check out Mom and Kiddo’s full post of this experiment HERE. Let us know what your results are when you make your own purple brew. What would happen if you tried different vegetables? What would happen if you used cream of tartar, lemon juice, salt, lemonade, or other materials from your kitchen pantry? Can you make your own litmus paper and test the pH of the solution?
Eggshell Geode Crystals
This project comes to us from Melissa Howard who is a Mom, Blogger, and photographer. This project nicely demonstrates how real-life geodes are formed in igneous and sedimentary rock. It also demonstrates super-saturated solutions and shows a nice variety of crystal shapes and formations.
YOU WILL NEED:
- clean eggshells
- water
- a variety of soluble solids: table salt, rock salt, sugar, baking soda, Epsom salts, sea salt, borax, or cream of tartar
- small heat proof containers (coffee cups work well)
- spoons
- food coloring
- egg cartons and wax paper or mini-muffin tins
WHAT TO DO:
- Crack the eggs for this project as close to the narrow end as possible. This preserves more egg to use as a container for the solution.
- Clean the eggshells using hot water. The hot water cooks the lining and allows you to pull the skin (egg membrane) out of the inside of the egg using your fingers. Make sure to remove all the egg membrane, if any membrane stays inside the shell it is possible that your eggshell will grow mold and your crystals will turn black.
- Use an egg carton lined with waxed paper or mini-muffin tins to hold the eggs upright.
- Use a saucepan to heat the water to boiling. .
- Pour half a cup to a cup of water into your heatproof container. If you poured half a cup of water into the container, add about a ¼ cup of solid to the water. Stir it until it dissolves. Likewise if you used a cup of water, add about ½ a cup of solid to the water. You wanted to add about half again the volume of the water as a solid to the mixture. When the initial amount of solid is dissolved continue adding small amounts of the solid until the water is super-saturated. Super-saturated simply means the water has absorbed all it is able to absorb and any solid you add will not dissolve.
- Add food coloring.
- Carefully pour your solution into the eggshell, filling it as full as possible without over-flowing it or causing it to tip.
Find a safe place to put your shells while the water evaporates. Crystals will form inside the eggshells as the water evaporates.
HOW DOES IT WORK?
Dissolving the crystals in hot water created what is called a “super-saturated solution.” This basically means that the salts took advantage of the energy of the hot water to help them dissolve until there was no more space between molecules in the solution. As the solution cooled, the water lost its energy and the crystals are forced from the solution to become a solid again. Since this happens slowly along with the evaporation, the crystals have time to grow larger than they were when the experiment started. Natural geodes in rock are form in much the same way as mineralized water seeps into air pockets in rock. This is also how rock candy crystals are formed.
You can visit Melissa’s great blog and see more pictures HERE.
Lemon Chemistry: An Acid-Base Experiment
Kari Wilcher runs a great blog. She was looking to teach her pre-school children about the Scientific Method while trying out some kitchen chemistry at the same time. Her plan was to show a dramatic acid-base reaction using lemons, baking soda, and a little dish soap. She writes:
“I firmly believe that children are never too young to be exposed to the scientific method and should follow it. I have found that the scientific method is very easy for them to understand, and follow, when presented to them in a simple way. I like to use a rebus (picture) to help my non-readers understand the directions. I also use these “big” words: data, hypothesis, prediction, and observation. We, including Momma, wear goggles (from the dollar store) and a lab coat (a.k.a. dad’s white button up shirt) because we are real scientists doing real science experiments…and it just makes us cool.”
You will need:
- Fresh Lemons
- A knife
- A small measuring cup & measuring spoon
- Baking Soda
- Liquid dish soap
- A clear cup for the reaction
What to do:
- Roll the lemons on the counter like dough. This releases the juice inside the lemon.
- Cut the lemon in half (adults only, please) and carefully squeeze out the juice into a small measuring cup. Note how much juice was created from each lemon and put the juice aside.
- Into the empty glass place 1 Tablespoon of baking soda.
- Add 1 teaspoon of liquid dish soap to the baking soda. Stir these up a bit.
- Pour the lemon juice into the cup and stir. Now watch the lemon suds erupt!
How does it work?
This is a classic example of an acid-base reaction. This is often done with vinegar and baking soda, but we liked Kari’s “lemon twist.” The baking soda (a base) and the lemon juice (an acid) combine to release Carbon Dioxide gas. The liquid soap turns the bubbles into a foam that often erupts right out of the glass.
Try it out and let us know how it goes!
You can check out Kari’s full blog post of this experiment including the worksheets she created HERE.
Do Birds Care What Color Their Food Is?
Would you want to drink green milk, how about orange mashed potatoes? The color of foods might affect just how much you want to eat them, but what about the birds in your neighborhood, would they care what color their food is? This sounds like an experiment in the making…. you coul even try this out for a science fair project, or just to learn something new while making your locals birds happy.
You will need:
- Several bird feeders that are the same size and type
- Light colored birdseed appropriate for the birds in your neighborhood
- Several colors of food coloring
QUESTION - What color of birdseed, if any, will birds prefer the most?
RESEARCH: Ornithologists (scientists that study birds) are rather certain that most birds can see in color. One reason they think this is because birds themselves are very colorful. In many species, male birds tend to be more colorful than females. This is likely because the males use their coloring to attract a mate, while female birds tend to have less coloring to provide camouflage as they protect their eggs in the nest. Before beginning a large experiment with lots of bird seed, you may want to put out a few small handfuls of different colored birdseed (see instructions for coloring birdseed below) to see how the birds near you react to different colored seed. You may also want to refer to books and talk to an ornithologist to get their opinion about how birds see the word.
MAKE A HYPOTHESIS: Use the information that you’ve gained from your research and make a hypothesis based on your question. An example might be “Birds will eat more green birdseed than other colors.”
EXPERIMENT: This is the fun part. You should get several bird feeders that are all the same size and type. Purchase a bird seed that is very light in color for this experiment. To color the bird seed, pour it into a bowl and then add food coloring that you can purchase from the store. Mix it up well with a spoon and continue to add color until all the seed is colored. You should sample at least a few colors and have one feeder with seed that has not been colored - this is called the control and it will give you something to compare your results to. Now just hang them up outside in the same location, and wait for your feathered friends to show up. This works best in an area that birds are used to feeding from a feeder – it can take birds over a week to find new feeders.
COLLECT DATA: Observe your bird feeder whenever possible, and keep track of how much seed is in each bird feeder each day. A ruler is helpful for this. You might also want to take pictures of the feeders and keep track of which kind of birds visit each feeder. Over time, you should be able to see if one color of seed gets eaten more than others.
MAKE A CONCLUSION: Once your experiment is done, you will be able to go back to your hypothesis and see if it is correct. Remember,it’s not bad if your hypothesis was wrong. The main thing is that you’ve learned something from your experiment, and hopefully you had some fun doing it.
If you try this, let me know how it goes!
If you need inexpensive bird feeders, you can get some on-line HERE.
Oobleck – The Corn Starch And Water Experiment
This may just be the easiest, messiest, and most fun science activity I know. It is a classic, and I have gotten several requests recently to post directions. You should know that if you try this activity and you are not smiling and messy with corn starch goo at the end, then you are definitely doing something wrong. Also keep in mind that this is not just about fun, there is some pretty amazing science going on here.
You will need:
- Cornstarch (a 16 oz. box is good for every 2-3 participants – but more is always better)
- Water
- Food coloring (we always say it’s optional, but it does make it more fun – don’t use too much or you could end up with colored hands…and clothes…and curtains)
- A large bowl
- A camera – you’re probably going to want to take pictures.
Everyone should roll up their sleeves and prepare for some gooey fun.
- This is easy. Pour the cornstarch into the bowl. Don’t rush to add water – take time to feel the cornstarch. Cornstarch does not feel like any other powder. It has a texture that can be compared to that of whipped cream. The grains of cornstarch are so small that they will fill into grooves of your fingerprints and make the prints stand out.
- After you’ve taken-in the feel of the powder, it is time to add water. (You should add the food coloring to your water before adding it to the powder.) There are no exact formulas regarding how much water to add, but it will end up being about 1/2 cup (120 ml) of water per cup (235 ml) of cornstarch. The secret is to add the water slowly and mix as you add it. Don’t be shy here – dig in with your hands and really mix it up. This is usually when you notice that this is not your average liquid. Add enough water so that the mixture slowly flows on its own when mixed. The best test is to reach in and grab a handful of the mixture and see if you can roll it into a ball between your hands – if you stop rolling it and it “melts” between your fingers – success!
We’ll get the the science soon, for now just dig in and explore. Notice that the goo does not splash (or even move) if you hit it quickly. Squeeze it hard and see what happens. How long can you get the strands of goo to drip? What happens if you let the goo sit on the table for a minute and then try to pick it up? How does it feel? Hows does it move? Try bouncing a ball on the surface of the cornstarch. You get the idea – explore!
30 minutes later…
So now goo is everywhere and you’re thinking you should probably start cleaning. Actual clean up of the goo is a snap. A bucket of warm water will quickly get it off your hands. It will brush off of clothes when it dries, and it is easily cleaned off surfaces with a wet rag. Important: Make sure you do not dump the goo down the drain – it can get caught in the drain trap and take the joy out of your day of science. Dump it in the trash, or even mix it into soil in the garden.
Cornstarch grains under the microscope
Now for the science…
Our cornstarch goo (sometimes referred to as “oobleck” from the Dr. Suess book) is what scientists call a “Non-Newtonian” liquid. Basically, Sir Issac Newton stated individual liquids flow at consistent, predictable rates. As you likely discovered, cornstarch goo does NOT follow those rules – it can act almost like a solid, and them flow like a liquid. Technically speaking, the goo is a SUSPENSION, meaning that the grains of starch are not dissolved, they are just suspended and spread out in the water. If you let the goo sit for an while, the cornstarch would settle to the bottom of the bowl.
So why does this concoction act the way it does? Most of it has to do with pressure. The size, shape, and makeup of the cornstarch grains causes the cornstarch to “lock-up” and hold its shape when pressure is applied to it. People have filled small pools with oobleck and they are able to walk across the surface of it (as long as they move quickly.) As soon as they stop walking, they begin to sink.
I hope you get to try this out. Let us know how your day with non-newtonian liquids went. Comment here, or, even better, send us pictures to comment@sciencebob.com . Have fun exploring!
-Science Bob
