Ward's World Activity Guides

Page 2 Expected Results: The flame from the matches heats the air in the bottle causing the molecules to spread out due to their increase in kinetic energy (movement energy), and some of the air molecules move out of the bottle. This, in turn, creates a vacuum inside the bottle that sucks the egg into the bottle. Once you put the egg in the bottle's neck, a seal is created, causing a partial vacuum inside the bottle. The flame inside the glass bottle extinguishes because of a lack of oxygen caused by the vacuum seal. Once the air cools down again in the bottle, the molecules will bunch up because they no longer have enough energy to stay as far apart, and this causes a partial vacuum. The number of molecules and the energy they have is not enough to maintain the original pressure, so the pressure in the bottle will drop. This causes the pressure inside the jar to become less than the pressure outside of the jar. The higher pressure outside pushes the egg through the glass bottle. The egg falls through fully intact. What goes in must come out. It's a little harder, but possible to get the egg out of the bottle using the same principles. You can do this by raising the pressure inside the bottle to push the egg out instead of in. Try blowing into the bottle while the egg is sit- ting in the opening of the bottle. Then when you stop blowing, the egg will fall into the opening of the bottle, and the higher pres- sure in the bottle should force the egg out of the bottle. If that doesn't work, take matters into your own hands by using a small knife to cut the egg apart inside the bottle, then shake out the pieces. After all, no one has ever actually witnessed Santa going back up the chimney! Follow up: • Repeat the experiment except try different size eggs or a water balloon. What changes do you observe? • Repeat the experiment except varying the amount of heat by increasing or decreasing the number of matches. What changes do you observe? • Watch a weather forecast on TV. Take note of the "H" and "L" moving around on the weather map. They are often referred to as zones of "high pressure" (H) and "low pressure" (L). How do these categories impact the weather forecast for different areas? Teaching notes: You can also use a more detailed description of the particle model to explain the science behind this experiment. Questions and observations for students: • How is barometric pressure measured? How does air pressure affect mercury in a barometer? • How does barometric pressure affect water chemistry and weather conditions? Why? • Encourage students to explore the difference between water pressure and air pressure. Are they based on, and do they fol- low the same physical principles? • Does this activity help explain why our ears pop going up in an elevator or on an airplane? • How does pressure change underwater, and how do pressure changes affect aspects of scuba diving? • How are the principles of air pressure used in paintball equipment? Disposal/Clean-Up: Discard leftover paper products in the trash. A Demonstration of the Pressure on Santa to Get Down that Chimney + ward ' s science 5100 West Henrietta Road • PO Box 92912 • Rochester, New York 14692-9012 • p: 800 962-2660 • wardsci.com Find materials for this activity at wardsci.com. Discover more free activities at wardsworld.com

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