Egg In A Milk Bottle – Fun with Frederick and Fleming

In our weekly segment Fun with Frederick & Fleming, we do different little science experiments that some would be fun to do with your kids. The goal with all of these is to use things you could find around the house or pick up at almost any store for a very little amount of money.

In today’s segment, we did another demonstration of air pressure. Since this “Eggsperiment” involves fire, it is best to do outdoors and with adult supervision.

Items Needed:

  • Glass milk bottle – Can often be found at an antique’s shop.
  • Peeled hard boiled eggs
  • Strip of paper
  • Match.

Instructions:

  1. Light an end of the paper on fire and once burning slide it into the bottle.
  2. Quickly put the peeled hard boiled egg on the top of the milk bottle.
  3. Sit back and watch

Science:

When you put the burning paper in the glass milk bottle, it heats the air up.  Hot air molecules are spaced farther apart than cooler air molecules are. So when the fire goes out, the air molecules go back to their pre-heated space and would normally result in air rushing back into the bottle. But with the egg blocking the air, the air pressure outside the bottle forces the egg into the bottle.

Challenge:

While getting the egg in the bottle is cool, the trick is then getting it out.  Take the milk bottle and get as much of the paper out that you can. Then act like you are going to drink out of it by tipping your head back.  Let the egg plug the bottle top from the inside.  Put it up to your mouth and blow into the bottle.  When you remove your mouth from the bottle, the egg pops back out.  You pressurized the inside of the bottle so it is now a greater pressure than the air around it forcing the egg back out once again.

 

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