Whether you’re looking for an easy science activity, a spring-themed experiment, some kitchen science, a hands-on egg exploration, or a kid-friendly introduction to chemistry, this egg science experiment is for you!
Eggs are one of the most versatile kitchen ingredients, and they can also be used to learn some science. In this activity, we will see what happens when calcium is removed from an eggshell!
Follow it up with our amazing and free All About Eggs learning kit for an all-around eggs-travaganza! Our printable includes 19 pages of egg science, history, art, math word problems, and language arts.
What makes an eggshell hard? Ask your kids, and they will have lots of suggestions. In my house, I heard “they eat cement” and “because they are related to dinosaurs” (DNA analysis shows that chickens are more closely related to the T-Rex than even alligators, who are also dinosaur descendants).
The eggshell hardness has nothing to do with cement or dinosaur DNA. Bummer! In reality, the shell gets its strength from calcium. Just like us, birds get calcium from the foods they eat because their bodies can’t make calcium.
Do your kids know what healthy foods they can eat to keep their bones strong and heart-healthy? Definitely have this conversation with them. I find that explaining why certain foods are more beneficial than others helps my kids make healthier choices. You can print our All About Calcium kit to aid the learning process.
A great way for kids to learn how calcium works is by seeing what happens when calcium is removed. If you leave an egg in vinegar overnight, some of the calcium will dissolve, and the egg will become soft. We don’t want that to happen to our bones!
I don’t know if you might consider this an unsavory scare tactic… but I shared with my kids that nutritional rickets (such as limb deformities) are considered the most common non-communicable disease of children in third-world countries. I noticed my kids looking at their glasses of milk with new eyes when they envisioned life without a fridge stocked up with milk, cheese, and yogurt.
(In the same vein, what does it feel like to be a mommy who can’t give her starving child a cup of milk? When you think about it, all life’s problems seem so insignificant, don’t they? When I was a child and complained about something petty, my grandpa always said there are people in the world who will take all my problems and call them blessings. It’s so profound and so true).
Egg Science Experiment
What you need
Egg (raw or boiled)
Jar (I’m using a 16 oz size)
What to do
- Half-fill a jar with vinegar. You can put the egg in before filling the jar, but make sure to do it very slowly so as not to hit the hard bottom. Ask the kids, what do you think will happen? For older kids, print out the scientific method recording sheet (in our library) and have them fill it out as you go. The hypothesis here can be: Placing eggs in vinegar will result in a chemical reaction that dissolves the eggshell.
- Put a chicken egg inside the jar. Make sure that the egg is completely submerged, but it’s okay if it floats.
Like us, you might immediately start wondering if the brown egg would lead to different results, so we ended up adding the brown egg too.
Right away, notice the tiny bubbles on the surface of the shells.
The bubbles result from a chemical reaction between the acetic acid in vinegar and the calcium carbonate in the eggshell. The formation of bubbles is the visual proof of the chemical reaction and the presence of carbon dioxide. (Fun fact: the way bubbles are produced here is the same way that baking powder makes pancakes rise when it comes in contact with the acidic buttermilk.)
By the way, if you are doing this experiment right now and wondering how in the world I got those fantastic close-ups, the answer is a professional-grade magnifying glass.
This magnifying glass is the best homeschool and science investigation tool ever!
- Keep an eye on your experiment throughout the day. What’s happening? Is the shell deteriorating? Older kids can record their observations (How does it look? How did it change?).
You might want to point out that the surface of the egg looks porous. “Porous” means that fluid can go through the material. Do you see what I mean?
My son also started wondering what would happen if we wiped the bubbles off the egg, so we did. What do you think would happen?
The bubbles came right back within seconds! Watch the short video below.
- Leave the egg overnight. It can be in the fridge or out, but be warned that if it’s too warm in your kitchen, the egg will go bad faster and might be more prone to burst than bounce. Also, as always, keep in mind that working with a raw egg carries the risk of catching some raw egg disease. So, wash your hands carefully after experimenting with them.
- The next day, gently take the egg out. You will probably still see the remnants of a shell, and it would feel soft and rubbery. If you drop the egg, it bounces!
What about the brown egg?
Well… when we took the white egg out, it was soft and rubbery. All good! Then, we poked the brown egg with a finger, and it was still hard. We poked it harder to see just how hard it was, and … the shell cracked, and the yolk started to flow out.
Are brown eggs tougher than white eggs?
If we were doing this experiment for publication in a science journal, we would repeat it a couple of times to see if we can replicate the results. Does it take longer for the brown eggshell to dissolve? Is placing white and brown eggs in the same jar skewing the results?
- If you want to remove the shell entirely, gently pour the vinegar out and add fresh vinegar.
Believe it or not, there is a lot of chemistry involved in this simple experiment. Chemistry is a branch of science that deals with elements and their changes during a reaction with other substances – producing heat or bubbles or even a brand new substance. Those reactions are our favorite part! Just check our baking soda and vinegar experiments!
If you have ever done baking soda and vinegar experiments, you might be interested to know that baking soda (sodium carbonate) and calcium in an eggshell (calcium carbonate) have many similarities.
They are both white powders, freely found in nature. And they are basic (with high pH). Their chemical formulas are similar because the carbon ion (CO₃) can form compounds with both sodium (Na) and calcium (Ca). The chemical formula of baking soda is NaHCO₃, while the chemical formula of calcium carbonate is CaCO₃.
Bones, teeth, eggshells are all things that require calcium for proper functioning. In today’s experiment, when acetic acid (vinegar) and calcium carbonate (in the shell) combine, the immediate acid-base reaction creates carbonic acid. Carbonic acid is unstable. It immediately begins to decompose into carbon dioxide and water, which we can observe with the naked eye.
The Science of the Naked Egg
Now the most fun part: hands-on investigation! Warning: Cover your work area with a plastic tablecloth. If you didn’t boil the egg before the experiment, it could burst.
How does the egg look? Does the egg look a bit… naked? He-he. What does it feel like? What does it smell like? Can it bounce? Can you see through it? Look at it against the light? What does yolk look like inside? What happens when you shake it?
There are so many things to do, touch, and see!
Study the egg with a magnifying glass.
Look at it with a flashlight.
If you used both white and brown eggs, did they react in the same way?
When you are done, poke the egg with a sharp object like a stick. What happens when you break the fragile membranes that hold it together?
FYI: My favorite pic of the year 🙂
Did I expect this massive explosion?
No, I didn’t.
Was I ready to take the pic?
No, I wasn’t.
The only reason this pic exists is that I was so surprised I pushed the button 🙂
I tried to replicate his explosion, but it wasn’t as spectacular.
Who knew that the breaking of an egg membrane could be so gorgeous? And don’t worry, the whole area was thoroughly sanitized and the old shower curtain we used for the experiment was thrown away.
For extra fun, repeat the same experiment but add food coloring to the vinegar. I added 1oz of red food coloring to the white egg.
One thing you might have noticed about the naked egg experiment is that the egg is growing larger with each passing hour. Why? Because it’s absorbing the liquid. Vingear is actually about 95% water.
Here you can see the regular egg in comparison with the egg that was in vinegar for one day. Noticably larger, right?
If you didn’t explode all your eggs by now, you can use one to reverse the process.
Yep, behold the shrinking egg. Just add your naked egg to a cup of corn syrup and observe it for a few days. You will notice that with each passing day, the egg shrinks a little more. It’s because the syrup is low in the water, and the water inside the egg travels across the membranes to equalize the water concentration. This is osmosis in action. After a few days, reverse the process and add water to the cup to fill the egg back up.
Do you want more egg science? Take it a step further and try to dissolve the shell of a duck egg or quail egg. How long does it take? What might this indicate about the shell’s composition?
Don’t forget the FREE bonus materials that come with this post! If you don’t have time to print it right now, PIN it for later!
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