Our science experiment fail turned into a major success. This year we are studying weather and one of the science experiments that I wanted to do was the egg in a bottle experiment because it shows you how air pressure works. The original experiment requires a glass milk bottle, one hard-boiled egg peeled, a piece of paper and a match. You simply (haha) light a piece of paper inside the glass bottle and then you place the egg inside the top of the bottle and when the flame is extinguished the egg slowly move its way into the bottle. The way it works is that the fire inside of the bottle heats up the air molecules, then the egg on top of the bottle reduces the oxygen and the flame goes out which causes the air in the bottle to cool. When the air pressure cools the pressure inside of the bottle is less than the pressure outside of the bottle and this creates a vacuum that sucks the egg into the bottle.
It sounds simple enough but we were unsuccessful because we couldn’t get the egg to go more than three-quarters of the way into the bottle and then it would get stuck. After approximately 20 failed attempts we began brainstorming ways to make the experiment work. We knew that we needed to heat the air molecules up inside of the bottle so that they could cool. We decided to heat the bottle up with hot water from the tap and then place the egg in the top of the bottle while we turned on the cold tap. We weren’t sure if it would work and we were ecstatic when the egg was sucked into the bottle successfully.
Now we wanted to get the egg back out of the bottle and the original experiment requires you to blow air into the bottle around the egg to reverse the pressure and force the egg back out of the bottle. This didn’t work for us either so again we put on our thinking caps. We decided to run the experiment in reverse so we moved the egg in the bottle back up to the neck and turned on the hot water. As the hot water heated up the water molecules it increased the pressure behind the egg and forced the egg back out of the bottle.
We were so excited! Finally, we had success but we wanted to make sure that it wasn’t a fluke so we duplicated the experiment five times and every time we achieved the same results. What started off as a fail turned out to be one of our best science lessons because the kids really had to apply the scientific method to turn this into a successful experiment. We concluded that the bottle we had which was a 13.7 fluid oz glass jar may have been too small and that was why we couldn’t keep the fire lit (not enough oxygen). We are going to acquire a larger glass milk bottle and attempt the original experiment again to test our hypothesis.
If you are interested in seeing us in action I will drop a link to our YouTube video I apologize in advance we were using a cell phone to video the experiment.