Did you know that you can remove the shell from a raw egg without breaking the shell? 

Do this by filling a 1-quart (1-liter) jar about three-fourths full with vinegar. Tilt the jar and gently place the egg in. You can also use a spoon to put the egg in the jar.  Be careful not to crack the egg. Observe the appearance of the eggshell immediately and then periodically until the egg shell disappears. This will take 2 to 3 days. 

What Happens?

The egg’s hard shell is made of calcium carbonate, commonly called limestone. When vinegar chemically reacts with the limestone, carbon dioxide gas is produced (you’ll notice the bubbles seen on the egg rising to the surface). The egg shell disappears, but the membrane beneath the shell does not dissolve in vinegar. Instead, the membrane becomes more rubbery in texture. 

Does the naked egg look larger than when it was covered with a shell? It should. This enlargement is due to water from the vinegar passing into the egg  through tiny holes in the membrane. This movement of water through a membrane is called osmosis. For more information about osmosis as well as an experiment that results in the removal of water from the egg,  see the SHRINKING EGG. 

For more ideas for science experiments, see Janice VanCleave’s Super Science Challenges.