An interesting science fair project that demonstrates an understanding of air pressure is putting an egg into a bottle. The result will leave an egg with a hardened shell still intact and inside a glass bottle that has a neck slimmer than the egg’s diameter. Fitting an egg inside of a bottle requires only a few household supplies. Photograph each step of the project to display on your science fair board for a well-rounded presentation.
Fill a bowl with white vinegar and place a hardboiled egg with the shell still on into the liquid. Allow the egg to soak for 24 hours. The vinegar makes the egg’s shell soft enough to go through the opening of the bottle.
Remove the egg from the vinegar and dry it with a clean paper towel.
Light four matches simultaneously and drop them into the opening of the glass bottle. Do this quickly so they burn for an extended period within the bottle.
Place the egg on the top of the bottle with the tapered end pointing upward. As the matches burn, they cause the air within the bottle to heat and expand, forcing a portion out of the bottle. When the matches burn out from lack of oxygen, the air inside the bottle cools and reduces in volume.
Observe the egg being sucked into the bottle. The reduced volume of air changes the pressure within the bottle, leaving a lower level of pressure inside the bottle than the pressure outside the bottle. The higher pressure outside the bottle forces the egg through the opening.
Leave the egg to dry for 24 hours and you will be left with a hard egg within the bottle.
Take the science project one step further by removing the egg from the bottle. Fill the bottle with white vinegar and let the egg soak for 24 hours. Dump the vinegar out and hold the bottle upside down in a sink. Run hot water over the bottle. As the air expands, it will force the egg back out of the opening.
This science project can also be completed with a shelled hardboiled egg without the use of vinegar.
Do not handle matches without a responsible adult’s assistance or supervision.