Three Egg Science Experiments for You and Your Kids
Or folded an egg in half?
Or bounced an egg on the table without making it break?
You and your kids can astound your friends and family with three easy egg science “eggs-periments.” All it takes is one secret ingredient and a little patience.
In this article I’ll show you how to remove the hard eggshell to discover what lies beneath an egg’s tough exterior.
Why Remove the Eggshell?
Scrambled, boiled, sunny side up… naked? Most kids (and grownups, too) are familiar with the many things you can do with eggs. Wouldn’t it be fun to try something with an egg that you’ve never seen before?
Removing the shell may be completely embarrassing for the egg, but it will be fascinating for you and your kids.
Creating naked eggs and eggs you can fold up isn’t for the impatient. Like many worthy science projects, this experiment takes time and a lot of observation.
The results will definitely be worth it!
Here’s a quick summary of the naked eggs adventure.
#1: Naked Eggs
Place the egg in a tall glass or jar and cover the egg with vinegar (that’s the secret ingredient).
Look closely at the egg. Do you see bubbles forming on the shell?
Leave the egg in the vinegar for a full 24 hours.
Change the vinegar on the second day. Carefully pour the old vinegar down the drain and cover the egg with fresh vinegar.
Place the glass with the vinegar and the egg in a safe place for a week. Don’t disturb the glass or the egg—this egg takes a long time to shed its hard exterior.
Observe the bubbles forming on the shell’s surface (or what’s left of it!).
After a full seven days have passed, pour off the vinegar and carefully rinse the egg with water.
Take a look at your naked egg. (It will be so embarrassed!)
The egg looks translucent because the outside shell is gone. The only thing that remains is the delicate membrane of the egg.
You’ve created an egg without a shell. Well, the chicken created the egg; you just stripped away the chemical that gives the shell its strength.
Without its shell, the egg is soft and pliable. You can bounce it on the table or squeeze it between your fingers. Just don’t squeeze too hard!
The thin membrane that is left is called a semi-permeable membrane.
Shine a light through the egg and it will look translucent. Pretty cool, huh?
#2: Secret Message
Here’s a cool variation of the eggs-periment:
Make a message appear on an egg and freak someone out. It’s kind of like a magic trick, but it’s better—it’s SCIENCE!
Boil the egg in a saucepan for 10 minutes.
Remove the egg and let it cool.
Use a crayon or a candle to write on the eggshell, like you’re making designs on Easter eggs. Write your name, a message or a design.
Place the egg in a glass of vinegar and wait for bubbles to form.
When the bubbling stops, pour out the vinegar and cover the egg with fresh vinegar.
When the second round of bubbling has stopped, remove the egg from the glass of vinegar and rinse it with cool water.
The eggshell is gone but you should be able to see what you wrote.
Wax does not react with acid (vinegar) so the shell remains intact underneath.
#3: Folding Egg
How do you fold an egg in half? The trick is to remove both the shell and the inside of the egg, leaving just the membrane. Here’s how:
The first step is the trickiest and requires a little practice. You’ll need to blow out the inside of the egg without causing too much damage.
With the help of an adult, use a sharp pin, a thumbtack or a skewer to poke a small hole in both ends of the egg. The hole should be about 1/8″ (3 mm) in diameter.
The next step is to scramble the inside of the egg in order to break the yellow yolk. The best way is to poke the yolk with a toothpick through the hole in the egg.
Blow all of the liquid out of the egg. Clean off one end of the egg with a moist towelette, cover the hole with your mouth, and blow the egg liquid out of the other hole. Hold the egg over the sink or a bowl while you are blowing out the insides.
Place the hollow egg in a tall glass and cover with vinegar.
The egg won’t be very dense, so you may need to place something like a spoon on top to hold it down.
Leave the egg in vinegar for a full 24 hours.
Change the vinegar on the second day.
Leave the glass with the egg in a safe place for up to 10 days or until all of the shell is dissolved.
When the bubbles stop forming, it’s a good indication that the eggshell has completely dissolved.
Pour off the vinegar and carefully rinse the membrane with water.
Carefully squeeze out all of the water from the membrane.
Gently blow air into one end of the egg and it will puff up.
You can also fold it down to practically nothing.
Toss and bounce the folded egg in your hands and the egg will restore its shape. The more you toss the membrane, the more water will evaporate and air will push into the membrane.
Dust the egg membrane with baby powder. Try to get some powder inside the egg. This will keep the membrane from drying out.
How Does It Work?
Let’s start with the bubbles that form when the egg is put in the vinegar. The bubbles are carbon dioxide.
Vinegar is a chemical called acetic acid. White vinegar you buy at the grocery store is about 4% acetic acid and 96% water.
Eggshells are made up of calcium carbonate. The acetic acid in the vinegar reacts with the calcium carbonate to make calcium acetate plus water and carbon dioxide bubbles.
You may have noticed the egg got a little bigger after soaking in the vinegar solution. Some of the water in the vinegar (remember it’s 96% water) traveled through the egg’s membrane in an effort to equalize the concentration of water on both sides of the membrane. This is called osmosis.
If you place your naked egg in a glass filled with corn syrup, the egg will shrivel. Since corn syrup has a lower concentration of water than an egg does, the water in the egg moves through the membrane and into the corn syrup to equalize the water concentration levels on both sides.
Take Naked Eggs to the Science Fair
How can you take this experiment even further? Turn the naked egg experiment into a science fair project. What happens when you use organic or free-range eggs compared to regular eggs? Do their shells differ in any way?
What about testing different concentrations of vinegar? Will this speed up the time it takes to dissolve the shell or the amount of shell that is dissolved?
Some Final Thoughts…
Whether you do this egg-citing experiment for the science fair or just to amaze your friends and family, I hope you learned something new and had fun. And you may just be able to answer that age-old question:
What came first, the rubber chicken or the rubber egg?
What do you think? All yolks aside, we’d love to see your naked and folding eggs, along with some secret egg messages. Tell us what you learned and share a picture of your stripped-down eggs below.
Image from iStockPhoto.
Steve Spangler is an author, teacher, toy designer, Emmy award-winning television personality and creator of a huge soda mess. His appearances on television demonstrate his passion for making learning fun. Other posts by Steve Spangler »