Did you know you can squeeze a hard-boiled egg into a glass milk jug without breaking it? It just takes some pressure manipulation.
What You Need
A hard-boiled egg
A glass jar/bottle with a mouth of a smaller diameter than the egg (but not too small!). Glass milk jugs work well.
A sheet of paper
What to Do
1. Cut a small strip of paper 1 inch wide and 3 inches long
2. Place the strip of paper in the mouth of the glass jar
3. Light the strip of paper and push it into the jar gently with the tip of the lighter (not your hand!).
4. Allow the paper to burn for a moment inside the jar
5. Place the hard-boiled egg on top of the jar
6. The egg should then be sucked through the lid
What's Going On?
When you light the fire inside the glass jar, the temperature will rise. According to the ideal gas law, the pressure will rise as the temperature increases so long as the volume remains fixed. This extra pressure will push up on the egg, allowing some air to escape.
Then when the match goes out, the temperature decreases and the air pressure decreases. Consequently, the air pressure inside will be less than the air pressure outside, and the egg will be pushed into the bottle.
You can see all of this happen in the video below.
Have you ever canned vegetables, fruit, or jam? How can you relate the canning process to the egg in the jar activity? Think about the little pop in the seal of the canned item.