Making an egg bounce is a fun way to learn how acid breaks down different substances. According to National Geographic Kids, an eggshell contains calcium, which makes it hard. There is a thin membrane underneath the shell that maintains the egg’s shape. When the acid in vinegar dissolves the calcium shell, the membrane stretches resulting in a “rubbery” effect. With a few household items you can entertain and impress others with your “special” ability to make a bouncing egg.
Place a cool, hard-boiled egg in the jar. Be sure not to crack the shell.
Pour vinegar in the jar until the egg is covered. Place the lid on the jar and twist once. Do not secure the lid too tightly.
Let the egg sit in the vinegar for two days until the shell has completely dissolved.
Remove the egg from the jar and rinse it in cool water.
Place the egg on a paper towel and let it dry. The egg will have a rubbery texture and you will be able to bounce it softly on a table or counter top. Do not attempt to bounce the egg from a height of more than one or two feet as the membrane will break.