What is elephant toothpaste?

It’s a super fun, and inexpensive, science experiment that results in a foamy explosion.  

It is similar to the soda pop geyser, but because you only need small amounts of the materials used, you can do the experiment over and over again without breaking the bank.  

It’s also less sticky, and cleans up quickly and easily if done outside.  

Science experiments like this one can easily be turned into a more well-rounded STEM project.  

Math is already involved, since your child will be measuring ingredients.  And, of course, the chemical reaction is science.  

After trying the experiment with the plastic bottle, you may want to encourage your child to engineer a different container to do the experiment in.  Can they create a volcano with Legos?  In the fall they can even use a small pumpkin for this twist.  

If your child loves STEM, they may also like some of these fun STEM activities for kids. 

Elephant Toothpaste Recipe

Affiliate links have been used below.  See my full disclosure for more details. 

Materials: 

• A Clean 16 oz. Plastic Bottle
• Liquid Dish Soap
• 1/2 Cup Hydrogen Peroxide 
• 1 Tablespoon Dry Yeast
• 3 Tablespoons Warm Water
• Food Coloring (optional)
• Small Cup
• Funnel
• Spoon

For the ultimate reaction, which can produce foam that shoots 5 or more feet into the air, you need to use what’s called 20-volume (or 6%) hydrogen peroxide.  This peroxide is stronger than what you find at the grocery store.  In the U.S. you can find this at hair salons or online.

We couldn’t wait to give it a try, so we used the standard 3% peroxide we had in the medicine cabinet.  

Although the reaction wasn’t as extreme, we were not disappointed with the results.

Why Is It Called Elephant Toothpaste?

The chemical reaction in this experiment is often referred to as “elephant toothpaste” because when it foams out of the mouth of the bottle it looks a lot like when you squeeze toothpaste out of a tube. 

Some joke that if it were really toothpaste, it would be the amount an elephant would need.  

Obviously, since liquid dishsoap is used, it should NOT be ingested. 

To make it look even more like toothpaste, you can squirt a few drops of food coloring along the inside walls of your empty bottle before doing the experiment.  This causes stripes to appear, similar to what you may see in several major brands of toothpaste. 

How to Make Elephant Toothpaste

Like I mentioned earlier, this experiment can get messy.  It is best done outside, where you can clean up easily with a hose.  

Begin by squeezing 4-5 drops of food coloring into your empty plastic bottle.  This step is completely optional, but the color does make the reaction even more fun to watch.  

Add 1 tablespoon liquid dish soap and swirl the bottle around to mix it with the food coloring.

Add your hydrogen peroxide to the bottle. Swirl it again to make sure it mixes well.

IF you want stripes, you can add a second color of food coloring, this time making sure your drops run down the inside walls of your bottle.

In your small cup combine the warm water and yeast together and stir for 30 seconds, making sure the yeast is dissolved as much as possible.

Use the funnel to quickly pour the  yeast mixture into the bottle.  

Remove the funnel quickly, as the reaction will start almost immediately.  

If you use the 6% hydrogen peroxide it can shoot several feet into the air, so be sure to get out of the way quickly.

How Does Elephant Toothpaste Work

Yeast contains an enzyme called Catalase.  This enzyme breaks down hydrogen peroxid (H₂O₂) into oxygen gas and water (H₂O).  

The oxygen gas gets trapped in bubbles made by the dish soap, producing that fantastic foamy solution that erupts out of the bottle.  

Once the foamy explosion is finished, you will notice the bottle and foam are warm to the touch.  That’s because the experiment not only causes a chemical reaction that produces the foam, it also causes an exothermic reaction — meaning it produces heat as well.  

If you use the standard 3% hydrogen peroxide, then the foam is safe to touch.  (I’ve heard 6% hydrogen peroxide can cause skin irritation to those with very sensitive skin.)

If your kids are anything like mine, they will find it hard to keep their hands out of it.  Mine spent a good 15 minutes playing in the foam afterwards.  

More Fun with Elephant Foam

Try some of the ideas below to take your child’s learning even further.  

• Does the amount of yeast used change the amount of foam produced?  Try using more or less yeast to see what happens.
• What about using more soap?  Experiment with different amounts to see what happens.  
• Does the reaction still work if you don’t mix water with the yeast before adding it to the soap mixture?

If you liked this post, you’ll also like:

• Simple Vanishing Ghosts STEM Activity 
• Make Scrumptious S’mores with a Solar Oven 
• Amazing Rising Water Experiment 

Originally published June 29, 2017. 

The post Fun and Foamy Elephant Toothpaste Experiment first appeared on There's Just One Mommy.

The bright orange fruits make cute decorations and are fun to use in a variety of pumpkin STEM activities.  

If you’re carving pumpkins this year, use one to make a simple pumpkin volcano.   It’s a fun fall twist to an old favorite science experiment.

If you have toddlers or preschoolers, you may want to let them explore whether or not your pumpkin sinks or floats before trying this activity.  

Older kids might enjoy some of these other Halloween STEM activities. 

Pumpkin Volcano Experiment

Materials Needed:

• Pumpkin
• Vinegar
• Baking soda
• Dish soap
• Sharp Knife
• Food coloring (optional)

To begin with, use the knife to remove the top portion of your pumpkin, much like you would when carving pumpkins.  This portion of the activity should be done by an adult.

Then let your child remove the seeds and pulp from the pumpkin.  They can use a spoon or their bare hands, adding a bit of sensory play into the activity.  

Once the pumpkin is hollowed out, sprinkle a healthy dose of baking soda into the bottom of the pumpkin.  How much you need will depend on the size of your pumpkin.  We used 2 Tablespoons for our small pumpkin.  You’ll want to use at least 1/4 cup for a larger pumpkin.  

To increase the amount of bubbles produced, squirt a little bit of dish soap into the bottom as well.  

If desired, you can add a drop or two of food coloring as well.  We chose to leave ours plain. 

When you are ready, slowly pour your vinegar into the pumpkin.  We used 1/2 cup on our small pumpkin.  Larger pumpkins may need a bit more.  

You’ll have an instant volcano in a pumpkin.

For even more fun, try adding pumpkin seeds to the bottom of your pumpkin.  

When the vinegar is added the foam will cause the pumpkin seeds to bubble up and spill out with the pumpkin volcano’s lava.

Does your child love being hands on?  Grab a spoon and let them try stirring. 

Mixing it helps more baking soda react with the vinegar and you get a second eruption.  

This pumpkin STEM activity is so much fun! 

Why Baking Soda & Vinegar Volcano Works

The vinegar is an acid.  The baking soda is a base. 

When these two materials mix, a chemical reaction happens.   

One part of this reaction is that carbon dioxide forms.  This gas causes the bubbling reaction that spills over the sides of the pumpkin.  

For a more detailed explanation, check out this post on why vinegar and baking soda reacts.  

I warn you, this simple Halloween science is addicting.

If your kids are anything like mine, the will ask to do it over and over again.  

We used half a box of baking soda and quite a bit of vinegar before I had to call it quits.  

This simple pumpkin volcano is so easy and so much fun to do in October.  

Other fun fall activities to try:

• Pumpkin Activities — Discover 10 fun activities with real pumpkins. 
• Apple Wrecking Ball STEM Activity — Challenge your child to make a wrecking ball with an apple.
• Vanishing Ghost Experiment — Kids of all ages will have fun with this STEM for Halloween.
• Apple-Scented Bubble Dough— Find out how to make amazing smelling play dough with just 2 ingredients.

Originally published 9/11/2015.

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This Lemon Battery STEM activity would be perfect to do in the classroom, at a scout meeting, or at home.   Use it in conjunction with a lesson on electricity, or do it as a stand alone activity.

If you are looking for more fun ways to keep kids busy and engaged, be sure to check out our other STEM activities for kids. 

Making a fruit battery is a fun science experiment for tweens and teens to do. 

Younger kids will have fun helping or watching what happens once you complete the circuit.

Take the learning further with this graphite circuit activity.  

Lemon Battery STEM Activity 

Materials Needed:

• 6 Lemons
• 6 Shiny Pennies
• Soapy Water
• Sharp Knife
• 6 Zinc Galvanized Nails
• 7 Alligator Clip Battery Leads 
• Mini 5 mm LED Bulb

Depending on their size, you may be able to make your battery using just 4 of your lemons.   We had fairly small lemons, and wound up needing all 6.  If you want, you can start with just 4 and add more as needed.  

Start by rolling and squishing your lemons a bit to get their juices flowing.   This is an important step as the acid in the juice is necessary to make your battery strong enough to light the LED bulb.

Then use your knife to make a ½-inch-long slit in each of your lemons.  Make sure the slit goes all the way through the lemon’s rind.  

Wash your pennies in the soapy water to remove any dirt.  Dry them thoroughly.  

Slide a penny into the slit of each lemon.   Be sure your pennies go in far enough to touch the lemon’s juicy insides.

Next, push a nail into each lemon so only a small portion of the nail sticks out.   The nail should be about 1 inch away from your penny.   You do not want your nail and penny to touch.

Arrange your lemons in a circle.  This will make it easier to connect them together.

Now you will need your alligator clips.  You can find these at a local car parts store or online.

Clip one alligator clip to the penny in your first lemon.   Fasten the other end of the lead to the nail in the next lemon. 

Continue connecting the clips in this manner until you get to the last lemon.

On your last lemon connect a clip from one alligator lead to the penny, but do not connect it to the next nail.  Instead you will use your last  lead to hook onto the remaining nail.   

You should now have 2 clips not connected to anything.

Attach these 2 remaining clips to the wires on your LED bulb. 

Look carefully at your LED bulb.  There should be one wire that is slightly longer.  The clip connected to the penny should clip to the longest wire of the bulb. (This is the bulb’s positive side.)   

Your bulb should light up. 

If your bulb doesn’t light up, try unhooking it and turning it to clip the leads onto the opposite wires of the bulb.

If it still doesn’t light up, check all your connections.  Make sure the clips are secure and the pennies and nails are far enough into the lemons and that they do not touch.

If it still doesn’t work and you opted to try 4 lemons first, try adding another lemon.

How a Lemon Battery Works

In order for a battery to work, you have to have 2 electrodes, separated by an electrolyte.

In your battery, the lemon juice is the electrolyte and the zinc nail and copper penny are acting as the electrodes.

Chemical reactions occur inside the lemon where the electrodes touch the juice. These reactions produce electricity as soon as you complete the circuit and a path is made with your leads from one electrode to the other.

Each lemon is one cell of your battery.  So if you use 4 lemons, you have a 4-cell battery.  If you use 6 lemons, it is a 6-cell battery.  

Extension Activities for Lemon Battery Experiment 

• Make a hypothesis.  Can other fruits or vegetables to produce electricity?   Test out your hypothesis and try it with oranges, apples, or potatoes. 
• How will using other metals affect your battery?   Try using other metals as your electrodes.   Instead of pennies try nickels or quarters.  Use different types of nails instead of the zinc ones.
• Can your battery light up more than one LED bulb?  Give it a try!  
• Now that you know how a battery works, use one to make an electromagnet. 

This Lemon Battery STEM activity is a fun way for kids to learn about circuits and electricity. 

You may also like these posts:

• Make Crystal Egg Geodes
• Engineer a Solar Water Still
• Design a Roller Coaster

The post Make a Lemon Battery STEM Activity first appeared on There's Just One Mommy.

As they get older it is important to keep that love of science growing, and there is no better way to do it than with fun experiments.

This soda and Mentos experiment is one that your child will beg to do over and over again.  Making a soda pop geyser is one of our favorite STEM activities to do outside.

This soda pop experiment is best done outdoors, preferably in a grassy area.  

You can use either regular cola or diet cola for this experiment.  Diet cola is often chosen because it is less sticky and therefore easier to clean up.  It also has the most explosive reaction.  

The brand doesn’t matter a lot, so feel free to buy a cheaper brand, which is helpful if you want to do the experiment several times.  (Trust me, your kids will want to do it several times.)

Looking for more explosive experiments?  Check out how to make elephant toothpaste.  

Affiliate links have been used below for your convenience.  See my full disclosure for more details. 

Soda and Mentos Experiment 

Materials Needed: 

• 2-liter bottle of cola
• 1 roll of Mentos mints
• clear tape

To begin the Mentos geyser science project get out 7 of the mints (half the package) and line them up so they are touching each other.  

Pull off just enough tape and secure one side of the mints to the tape.  This will enable you to get all the mints into the cola quickly, while still leaving enough surface area of the mints for the experiment to work.  (You can also buy this special Geyser Tube to help get the Mentos in all at one time.)

Once your mints are ready, position your pop bottle firmly on the ground so it won’t tip over.

Then carefully open the bottle of soda pop.  Try not to shake it, as this will reduce the effects of the experiment.  

Drop the tape holding your mints into the cola and quickly back away.  Watch the amazing soda pop eruption!

Why does the Mentos geyser experiment work?  

Carbon dioxide is pumped into pop bottles at the factory.   This is what causes bubbles to rise to the surface when you first open the soda.

Mentos candies actually have tiny pits all over the surface.  These pits are the perfect place for those little carbon dioxide bubbles from the cola to collect.  

Since the Mentos are heavy, they quickly sink to the bottom of the bottle.  Eventually all those little air bubbles that collect on the candy work to push the cola up and out of the bottle in a dramatic way.

Extensions for the Coke and Mentos Experiment 

Want to take the experiment even further?  

• Have your child guess how high the soda pop will erupt.  Then measure to see how close they are.  Mark distances with sidewalk chalk or tape on an outdoor wall and place your bottle against the wall to see how high it goes.
• Determine whether temperature affects the results.  Try the the soda pop experiment with a cold bottle of soda and a warm bottle.  Does one react better than the other?  
• Experiment to find out which type of soda pop has the biggest reaction with Mentos.  Try cola, diet cola, orange, and a clear soda pop.
• Experiment with the candies used.  Do you get a bigger reaction if you use more Mentos?   What if you use a different flavor?  

Making things explode is definitely one of my son’s favorite types of science experiments.  

Luckily I planned ahead and had enough materials to do the soda and Mentos experiment several times.  It was definitely a huge hit.  

Other kids science experiments you may like:

• How to Create Beautiful Egg Geodes 
• Amazing Rising Water Experiment 
• Ivory Soap Explosion 
• How to Make a Rubber Egg
• Make a Cloud in a Jar

   

You can find this fun experiment and many more in our co-authored book, Up! 

Originally published July 25, 2016

The post Super Fun (and Explosive) Soda Pop Geyser Experiment first appeared on There's Just One Mommy.

This week we had fun with a super simple egg experiment.

Your child will be fascinated when you discover how to make a rubber egg.

For more egg science, check out our floating egg experiment, too.

Egg experiments are perfect for spring.

For more fun with eggs…try making your own egg submarines.

Rubber Egg Experiment

Materials Needed:

• 1 raw egg
• vinegar
• container large enough to hold egg and vinegar

Making a rubber egg is super simple.

Place your uncooked egg into the container and cover it with vinegar.

You will notice that bubbles appear on the egg’s shell almost immediately.  After a few minutes the area surrounding the egg will be full of bubbles.

Place your egg in a cool, dark place for at least two days.

After two days, take out the egg and dry it off.  The egg will be noticeably larger than it was.

We got another egg out to compare the two.  Have your child compare the sizes and how each egg feels.

The egg feels rubbery!

Gently squeeze the egg.  You can squish it just a bit.

Glowing Egg Experiment

Take the activity further by making your rubber egg glow.

Take the egg into a semi-dark room.

Place a flashlight underneath the egg and check out the results.

The rubber egg will glow!   How cool is that?

Bouncing Egg

Finally, try bouncing your egg on a shallow dish.

We were able to bounce the egg gently several times from a height of 3 inches.

Remember, it’s still an uncooked egg, and eventually it will break.  (And, since it’s a raw egg — make sure your child washes their hands once they are finished.)

Why does the rubber egg experiment work?

The vinegar is an acid.

It dissolves the calcium carbonate that makes up the egg’s shell — the carbonate part is what causes those carbon dioxide bubbles you see during the experiment.

What’s left is the egg’s membrane, which will absorb some of the vinegar.  This is what causes the egg to get larger.

Extensions to the rubber egg experiment:

• Try the experiment with a white egg and a brown egg.  Does one have a shell that dissolves faster?
• Does the experiment work with a hard boiled egg?

Spring is the perfect time to try a few egg experiments of your own.

You may also like:

• Get an Egg in a Bottle without Breaking It 
• Simple STEM Activities for Kids
• Plastic Egg Activities 

First published on March 23, 2016.

The post How to Make a Rubber Egg first appeared on There's Just One Mommy.

I’m not sure what the fascination is, but the kids will bring them out, place them in the sink to thaw, and then start the whole process over again.

This love of melting ice is what inspired one of our favorite Valentine’s Day STEM activities.

Our  Valentine’s Day Science: Melt the Frozen Heart was a huge hit and I couldn’t wait to share it with you.

Frozen activities for preschoolers are always fun.  

This super simple science activity is a fun Valentines activity for kids.  It also would be a huge hit with Disney’s Frozen fans.

Melting Frozen Hearts

Materials Needed:

Affiliate links provided below.  See my full disclosure policy for more details. 

• Ice Cube Tray
• Eye Dropper (Pipette)
• Small Plastic Hearts (We used these.)
• Small bowl or tray (to contain the mess)
• Small container for water

Fill the spots of your ice cube tray half way with water and freeze.

Once it is frozen, add a plastic heart to each ice cube space.  Finish filling with water and freeze again.  This will ensure your heart is in the middle of each ice cube and not right on the top or bottom.

Once frozen, get out one frozen heart for your child to experiment with at a time.

Fill your small container with room temperature water and allow your child to use the eye dropper to drip water on the frozen heart.

Set a timer to see how long it takes before the ice melts enough to remove the heart.  Use a chart to record the time.

Will hot water make the ice melt faster?

Have your child estimate how quickly they think the heart will melt using hot water.

Then set the timer and let them experiment, using the eye dropper to drip hot water onto the ice cube.  Record the time on your chart and compare it to the time from using room temperature water.

(Related Post: 20 Ways to Play with Ice)

Younger children may be happy with just these two activities.  They may even want to try it again and again.

Not only are they learning about how different water temperatures affect the ice, they are also building fine motor skills and hand muscles by using the eye dropper.

For older children you may want to continue the Valentine’s Day experiment with some of the following ideas.

• How long will it take to melt on its own?  Place one of the frozen hearts in a shallow bowl and set it aside.  Set a timer and check the ice cube every 5-10 minutes to check its progress.  (Ours took over an hour!)  Record your findings.
• How else can you get the ice to melt faster?  Have your child shake salt all over the ice.  What happens?  Check the ice cube every few minutes.  Record how long it takes to melt enough to remove the heart.
• What other ideas does your child have?  Let them experiment, making only one change at a time.  Time and record the results on your chart.  (My daughter decided to try shaking the frozen heart in a baggie after adding salt to see if it would melt faster than with just salt.  It did!)

Will this activity put a stop to the endless toys found in the freezer?  Probably not.

But this Valentine’s Day science activity  is a fun way to encourage thinking skills and foster a love of science.

You may also like:

• Discover the Science of Sledding 
• Cherry Explosion:  Sweet-Smelling Fizzy Science 
• Take Your Child’s Love of Exploring to New Heights with Up! 

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The post Valentine’s Day Science: Melt the Frozen Heart first appeared on There's Just One Mommy.