What you'll need:
- Two raw eggs, still in their shell
- One glass of water
- One glass of vinegar
- Carefully place one egg in the glass of water.
- Carefully place the other egg in the glass of vinegar.
- Leave the eggs to stand in a safe place for at least 48 hours before coming back to check on them.
The egg you placed in water stayed the same, but the egg you placed in vinegar now looks more like a rubber bouncy ball (you might need to rinse it under warm water first).
So what’s going on? The acid in the vinegar (acetic acid) reacted with the calcium carbonate in the eggshell, breaking it down and leaving the membrane exposed underneath.
You may have noticed bubbles coming off the eggshell as soon as you submerged it in the vinegar, these are bubbles of carbon dioxide, a gas that is produced during the reaction (the same gas you find in bottles of soda).
The egg also gets larger during the experiment through the process of osmosis. The vinegar slowly moves through small holes in the membrane, which aren’t big enough to allow the egg to escape in the other direction.
Don’t be afraid to have some fun with your new rubber egg. Softly squeeze it and try dropping it from a small height to see if it bounces. It may burst at some point, but that's ok, you can always make more bouncy rubber eggs!