3. Record what you see (bubbles rising from the egg)
4. Leave the egg in the vinegar for one day.
5. Remove the egg and feel it.
6. Record your observations (the egg shell will be soft) bag closed.
Eggs contain something called "calcium carbonate". This is what makes them hard. Vinegar is an acid known as acetic acid. When calcium carbonate (the egg) and acetic acid (the vinegar) combine, a chemical reaction takes place and carbon dioxide (a gas) is released. This is what the bubbles are made of. The chemical reaction keeps happening until all of the carbon in the egg is used up -- it takes about a day. When you take the egg out of the vinegar it's soft because all of the carbon floated out of the egg in those little bubbles.