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The Great Deflate Debate Formal ReportMost 10 year olds have been to a lot of birthday parties, and at most of them there are balloons. It seems like the helium balloons from these parties never last all that long before they begin to deflate. So we started thinking, what will keep a balloon inflated the longest? Or is our best bet for balloons helium? This became the testable question for our science fair project.We decided to conduct research on different gasses to help us formulate a good hypothesis. Since balloons are often filled with helium to make them float, we started our research with that gas. We found that helium is one of the lightest atoms. It has 2 electrons in only the 1st layer, and only two protons which makes it very small. The low density of helium is why balloons filled with it float. Since it is so small we thought that might be the reason helium balloons seem to deflate faster than others. Maybe the small size of the gas molecules allows them to seep through the balloons more easily than other gasses. Balloons are also often filled simply with an air pump using the regular air in our atmosphere, so this led us to research our atmosphere. We found that our atmosphere is made up of 78% nitrogen, 21% oxygen and 1% other gasses when the air is dry. The final 1% includes many other gasses such as carbon dioxide and argon. Usually there is water vapor in the air as well though and this can be account for about 1% of the atmosphere as well (lowering the amounts of other gasses when the air is humid). Since the air is mostly composed of nitrogen we specifically researched that gas. We learned that nitrogen is the 7th lightest element (7 electrons and protons). Nitrogen gas in our atmosphere is found as a compound of two nitrogen atoms. Its atoms are bigger than helium atoms, but smaller than those in carbon dioxide.Most people have probably blown up a balloon with their breath as well. We learned in class that humans take in the oxygen from the air in the respiration process and release carbon dioxide as waste. That means that the air we breathe out will contain more carbon dioxide than regular air. So we researched carbon dioxide. We discovered that Carbon is the 6th lightest element (has 6 electrons and protons) and oxygen is the 8th lightest element (has 8 electrons and protons). Carbon dioxide is created when one carbon atom bonds with two oxygen atoms. Since it is a compound, or groups of more than one type of atom, the gas molecules are larger than both nitrogen and helium gas. Finally we researched balloons. Most balloons are made either from mylar or latex. In our project we’ll be using latex balloons because the latex balloons are faster to deflate than mylar. Latex was originally made from the sap of rubber trees and was completely natural, but now some latex is synthetic or man made.Since our research showed that carbon dioxide was made from the biggest atoms, we thought it would seep out of the balloons slower that the other gasses and this led to the following hypothesis. If we use carbon dioxide, regular air, and helium to inflate a balloon, then the balloon filled with carbon dioxide will stay inflated the longest, because the carbon dioxide molecule is the biggest out of our testing gasses, so it will not seep through the latex as fast as the other gasses. Now it was time to design an experiment to test our hypothesis.We wrote a basic procedure for testing the air in our balloons and only changed it slightly while performing our test since the balloons deflated faster than we expected. Our procedure for the experiment follows these steps.1. Fill three balloons with Helium2. Label the balloons with gas type and number 1-33. Repeat steps 1 and 2 for the 3 Regular Air and 3 Carbon Dioxide balloons.4. Measure the circumference of all balloons at the widest point and record in centimeters.5. Every 2 hours record the circumference of the balloons for at least 6 hours.6. Compare results to determine which gas keeps the balloons inflated the longest.In order to complete our experiment we needed these items.9 Identical Latex BalloonsHelium TankCarbon Dioxide TankAir TankPencilPaper For Recording ResultsCamera For DocumentationCloth Tape MeasureClock for tracking timeWe had a difficult time finding a carbon dioxide tank for sale that we could afford to buy, and that had a nozzle that could be used to fill up a balloon since most of them were made for other reasons. So we checked around to find a store that might have a CO2 tank, and be able to fill up the balloons for us. It turns out that carbon dioxide is used to power paintball guns, and Dick’s Sporting Goods of Allen was very kind and filled up all of our carbon dioxide balloons for free.We followed our procedure and collected our data for 3 trials for each type of gas. The chart below gives our results.Measurement TimesRegular AirCarbon DioxideHeliumStarting Circumference66.0 cm58.9 cm61.1 cm2 Hours66.0 cm52.0 cm59.3 cm4 Hours65.9 cm40.7 cm56.7 cm6 Hours65.9 cm34.3 cm55.8 cm24 Hours Later65.5 cm27.3 cm43.0 cm In our project we tried to find out which gas would keep a balloon inflated the longest. Our hypothesis stated that carbon dioxide balloons would stay inflated the longest, but our hypothesis was incorrect. We thought that since carbon dioxide formed the biggest molecule of the gasses we tested , it would not seep through latex as fast as the other gasses. In our experiment the carbon dioxide deflated the fastest. As an example, one of our CO2 balloons started at 58.9 cm in circumference, but after only 6 hours it had deflated to 34.3 cm in circumference. We think this might be the result of unbalanced amounts of CO2 inside the balloon and outside the balloon. Since the balloons filled with the regular air pump contained the same air that was in the room, they deflated the least because it was balanced. The helium balloons also deflated more quickly than the regular air balloons, but slower than the carbon dioxide balloons. When we saw how quickly the carbon dioxide balloons had deflated, we decided to fill a balloon with our breath, because we realized that humans don’t breathe out only carbon dioxide. We then noticed that our breath balloons had not only deflated less than the carbon dioxide balloons, but they actually resembled our data of the air balloons. We did not include the measurements from the breath filled balloons on our data chart since they were not started at the same time as the other balloons in our experiment. If we were to study this further we would like to try balloons filled with nitrogen and oxygen only to see how quickly they deflate. ................
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