Naked Egg (Bouncy Egg)

When an egg is placed in vinegar, the acid reacts with the calcium carbonate of the eggshell, producing carbon dioxide bubbles and dissolving the shell. What remains is a soft, rubbery membrane that can stretch and even bounce.

1. Place a raw egg in a jar and cover it completely with vinegar.
2. Observe bubbles forming on the shell as vinegar (acetic acid) reacts with calcium carbonate.
3. Leave the egg for 48–72 hours.
4. After soaking, carefully remove the egg, rinse it, and gently rub away any remaining shell.
5. Examine the “naked egg” - soft, squishy, and translucent. Try gently bouncing it from a small height.
6. Shine a flashlight through the egg to see the yolk inside.

How to make bouncing naked eggs - Letterbox Lab:

📄🎞️ Bouncy egg - Science Museum Group: https://learning.sciencemuseumgroup.org.uk/resources/bouncy-egg/

• Add food coloring to the vinegar to dye the egg’s membrane.
• Combine with osmosis experiments by transferring the egg into corn syrup or salt water.

• Handle naked eggs carefully—they are fragile and can burst easily.
• Keep raw eggs refrigerated to reduce risk of bacteria.
• Wash hands thoroughly after handling raw eggs.
• Clean up spills immediately.

• What happens to the eggshell when it sits in vinegar? (It dissolves because acetic acid reacts with calcium carbonate, producing carbon dioxide gas.)
• Why does the egg feel rubbery after the shell is gone? (Because only the semi-permeable membrane remains, which is flexible and soft.)
• Why does the egg sometimes grow larger? (Water moves into the egg through osmosis, making it swell.)
• Can you see inside the egg when you shine a flashlight? (Yes, because the hard shell is gone and light can pass through the thin membrane.)
• Will the egg eventually burst if bounced too high? (Yes, because the membrane is delicate and cannot withstand strong impacts.)