Similar to human bones, egg shells contain calcium carbonate. Calcium carbonate can be used as a dietary supplement when a diet does not consist of enough calcium. Calcium carbonate has the formula CaCO3 and is composed of Calcium (Ca), Carbon (C), and Oxygen (O) atoms.

Put an egg in a glass.


Fill the glass with vinegar.


Vinegar contains acetic acid, CH3COOH, and is made up of Hydrogen, Carbon, and Oxygen atoms.

Wait 3 days.

The calcium carbonate within the egg shell reacts with acetic acid in the vinegar. The calcium carbonate separates into calcium and carbonate parts. The carbonate part forms carbon dioxide and can be seen as bubbles in the vinegar. The calcium part floats free.







On day 3, the vinegar is drained and the egg is rinsed. The egg shell has dissolved and leaves behind the egg membrane. The membrane is not as durable as the shell, but holds the egg together.



The result is a translucent, flexible, bouncy egg membrane.



The membrane holds together during gentle bouncing.





The membrane holds the egg together for gentle handling. With a strong bounce, the membrane ceases to hold the contents of the egg together.