 Welcome back to Kids Fun Science. My name's Ken. Today's experiment is neutral buoyancy. As always, adult supervision is required. What you need for this experiment is a plastic cup, olive oil, rubbing alcohol, water, and an eyedropper. Some safety precautions go in here. Make sure you perform this only under adult supervision. Rubbing alcohol is very poisonous if ingested and is flammable, so keep away from open flame. To set up this experiment, you're going to need rubbing alcohol and a plastic cup. So you're going to pour the rubbing alcohol about halfway full. It doesn't have to be precise, but about halfway. And once you get that done, then we are going to add the olive oil. So just go ahead and get your olive oil. I don't think it matters if it's lighter or regular. I pour it in the cup because I'm going to use an eyedropper. It makes it a little easier than trying to put the eyedropper in the olive oil and contaminating it. So then I got the olive oil there in my cup and I got a cup with mini there with water, just regular tap water. So what we're going to do is take an eyedropper and we're going to pull out some of the olive oil and we're going to put it in the rubbing alcohol. And what it's going to do is it's going to make some some really neat spheres. As you see as they're dropping down little round ones there going down and they'll just sink all the way to the bottom. So go ahead and make a whole bunch of those. And once we get that done, it should look something like this. I'll come up to the top view so you can see what the the olive oil looks like a little little like clear balls there. So that's pretty cool. And so those are on the bottom, you can make more than if you want to. Now the tricky part is so we're going to start adding water. If you add it too quick like I am right here, it will start popping the olive oil spears. So you got to be very careful when you're adding the water. You could add it drop by drop with an eyedropper that it will take a very long time as you're going to have to do hundreds of drops because it will pop the spears. If you end up popping too many of the olive oil spears, go ahead and add a little bit more. They will sink to the bottom, but you do not want to put the water in. I'm doing a little bit too fast here. So you want to go a little bit slower and I'll show you how I'm doing it before I was just doing the eyedroppers. I started pouring it in just to speed it up a little bit, but the eyedroppers are guaranteed that it won't pop them, but you do want to go very slow. So gently, if you're going to do without the eyedropper, gently pour it against the side of the cup and very slowly drips or pouring very slow at a time, because if you if you go too fast, it will ruin the olive oil. So as you can see here, I'm just kind of going this. When you get to a point where you start to get more saturated, then you can start doing drop by drop or you can do drop by drop the whole time. If you want the experiment to completely not destroy all the olive oil. So that's how I do it right here. As you can see as the water is starting to get in there, the solution is getting a little bit more mixed up water and alcohol, rubbing alcohol. And so you can start to see the spheres are starting to become neutral buoyancy. And we're going to see that as we go a little bit more as they add more and more water. I'm going to start pretty soon going to drop by drop as we go. But I'm going to explain the science behind this. So the science behind this is the olive oil initially sinks because it's denser than the rubbing alcohol, but however it is less dense than water. So by adding the water to the alcohol, the density of the water slash alcohol solution gradually increases until it becomes equal to that of the olive oil. At this point, the olive oil will either sink or nor float. It will become suspended in a state of neutral buoyancy. The density of the olive oil is now equal to what the surrounding solutions like fish, submarines, and the Goodyear blimp all experience neutral buoyancy if the density is equal to their surroundings. The olive oil is really interesting to observe because it forms these tiny little spears that we saw earlier when we added to the water. This is because oil does not mix with water due to oil's non-polar nature. Water molecules are polar, meaning that it contains both a positive and negative end. A non-polar substance such as oil is completely neutral so it doesn't really mix with the polar substance. This property of the oil makes it easy to observe when neutral buoyancy has been achieved, as you can see right here. I hope you enjoyed this video. Remember to click thumbs up and to subscribe, and thanks for watching!