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Easter Egg Etching Use chemistry to dissolve eggshells and create beautiful designs. Collect • Three hard-boiled brown eggs • White vinegar • Masking tape • Scissors • Rubber bands • White crayon or tapered candle • Two clear glasses or bowls • Large spoon • Sponge • Water Make masks 1. Wrap one of the hard-boiled eggs with a few rubber bands. 2. Cut shapes or strips out of the masking tape, and then add them to the second egg. Use your finger to smooth the tape over the shell so that liquid cannot get between the tape and the shell. 3. Use a white crayon or the end of a tapered candle to draw on the third egg. Etch your eggs 4. Fill a large clear glass or bowl with enough vinegar to submerge an egg. Fill the other glass or bowl with water. 5. Slowly lower the first egg into the vinegar bath using a large spoon. Wait four minutes and then remove the first egg and place it in the water bath. While waiting, observe what’s happening to the egg. Can you see any bubbles? 6. Gently wipe the egg with a sponge to remove a thin layer of the unmasked parts of the shell. 7. Repeat the four minute vinegar bath and the water bath rinse with the remaining two eggs. Unmask your eggs! 8. Remove the tape and the rubber bands from your eggs to reveal the etched designs. What’s happening The calcium in eggshells make the shells strong and protects the inside of the egg. When eggs are added to acidic vinegar, the acid starts to dissolve the calcium of the shell. The longer the egg is submerged in vinegar, the more shell is removed. The masking tape, rubber bands, and wax act as masks to guard parts of the egg brown, while the unmasked part of the egg becomes a lighter shade. Take it further! • Try leaving each egg in the vinegar bath for a longer period of time. • After rinsing the egg for the first time, place it back in the vinegar bath again to repeat the process. What do you think will happen? What do you think would happen if you only dipped half of the egg in vinegar for a second bath? • For more colors, dye white hard-boiled eggs with food coloring, let them dry, and then follow the etching instructions above. 601 Light Street Baltimore, MD 21230 • www.marylandsciencecenter.org
