Bouncy Eggs

You need an egg, a glass and white vinegar.
Put the raw egg in the glass and cover with white vinegar. WAIT 3 days (I think we have got the time). gently rinse in tap water. Your egg is now translucent and BOUNCY!
WHY?
If you soak an egg in vinegar the eggshell will absorb the acid and break down, or dissolve. The calcium carbonate will become carbon dioxide gas, which will go into the air. What is left is the soft tissue that lined the inside of the eggshell.