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.
- 달걀껍질을 딱딱하게 만드는 탄산칼슘은 식초와 화학 반응을 일으켜 달걀에서 거품이 일어나고 껍질이 부드러워지게 된다.