 Couple safety precautions make sure you wear safety goggles avoid overpressuring the bottle do not pump the bottle up more The fist keeper more than a hundred times when releasing the pressure and screw the fist keeper slowly from the bottle Then never aim the fist keeper at another person and use the fist keeper with but do not use the fist keeper with a glass bottle For today's experiment, we need a bottle Straw and a balloon and a fist keeper. All right, so we want to blow up the balloon Inside the bottle so when you try that Without the straw it gets blocked because it seals up the end and there's air in there So you can't push any more air in So if you use the straw and you put it in this way and then blow it up And then you could pull out the straw and then you could blow up the balloon inside, right? And then we're going to do is tie a knot in it if I could tie a knot and push it down Actually There it goes. All right, so now we got the balloon tied in the bottle and I'll take your safety glasses Come on. You never want to pump the fist keeper over a hundred times because the pressure in the bottle Could explode the bottle so you want to keep it under there. We'll do about 70 Make sure you put it on secure tight to the bottle and then we're gonna observe the balloon When we start pumping up the bottle So the science behind this is this experiment is a perfect illustration of Boyle's law which states that As a pressure on the gas increases the volume decreases as the bottles filled with more air More molecules collide with inside the balls of the balloon causing the balloon to shrink That's 50 right there and you can see it's starting to get smaller as we're pressing more air in The balloon in the air is getting smaller. That's not leaving it. It's just compressing it As for the expansion in volume when the fist keeper is released Boyle's law Also states that as the pressure exerted on the gas decreases the volume increases So as a compressed air within the bottle escapes the pressure in the balloon Decreases it causes the balloon to expand to its original volume. Notice that the balloon does not expand indefinitely, however Since atmospheric pressure is still being exerted on the balloon at the pressure about 14.7 pounds per square inch PSI so the volume of the balloon will be kept in check 75 you can see it's a lot smaller. So now when we open the fist keeper It gets bigger. I hope you enjoyed this video. Remember to click thumbs up or to share if you enjoyed it. Thanks for watching