 Hi, I'm Ashley from the North Carolina School of Science and Math. Today we're going to talk about three of the five different states of matter. We'll show you some things that can help you understand more about these three states of matter. When we're finished, you'll have a better idea of what matter and those different states are. We'll even learn that different states of matter may appear in one substance. While watching the video, feel free to pause it anytime. Here's what you'll need to do the first experiment in this video. For our second experiment, you'll need these things. This is what you'll need for our third experiment. You may also want to work with a partner. Let's start talking about matter. Matter is anything you can see, touch, or feel. It's the material that everything in the universe is made from. You are made of matter. The mass of something refers to the amount of matter that makes up an object. Anything that takes up the space is matter. As we said, we'll be talking about three of the five states of matter found in nature. Let's try something. Hold your hand close to your mouth and blow on your hand. If you feel the warm air on your hand, you are experimenting one state of matter. Next, try touching the tip of your finger to your tongue. Your fingertip becomes wet with saliva. This is another state of matter. Now, touch your hair and your nose. Can you guess what state of matter these are? A solid is any material or substance that is not a liquid or a gas. Solids have a definite shape and volume. A cube, pyramid, or sphere are all solids. They have length, width, and depth. They are not hollow. A liquid will flow and always take the shape of the vessel into which it is poured. Water is probably the first example that comes to mind. A gas is a state of matter that has mass, but no shape. It also fills and takes the shape of a container. The air we're breathing right now is a mixture of gases. We're going to try some experiments with different states of matter. We're going to make a hypothesis or an educated guess about what will happen. Then we'll observe, record, and interpret the results. Let's pause the video and get out the materials we'll need for our first experiment. Oh, and when you try these, please be very careful. These activities are fun, but can make a mess, so follow the instructions and take care. To do this first experiment, it's important to use a bag without holes. So the first thing you'll want to do is test the Ziploc bag by pouring half a cup of water into it and turning it upside down over a sink. If it leaks, get another bag. With a partner to help, take the now empty Ziploc bag and pour one fourth cup of vinegar and one eighth cup of warm water into the bag. Take a piece of paper towel made into a square measuring roughly 3 by 3 inches per side. Put about one and a half teaspoons of baking soda into the center of the square. Fold the square twice to make a little packet. Carefully open a portion of the bag and quickly add the packet you just made and zip the bag shut. Give the bag a little shake, put it down on the table, and stand back and observe. What's happening to the bag? What do you see happening to the packet you made inside the bag? When the vinegar and baking soda mix, they react chemically to form new substances. One of those is a gas called carbon dioxide. That's the gas being given off by the bubbles. Those bubbles of carbon dioxide are what makes the Ziploc bag expand. Speaking of expanding, keep an eye on your bag. If it gets too full from all of the gas, open it up and let some out so the bag does not break open from the build-up pressure. Our first experiment was one where we learned something about gas. A state of matter that has only volume and no shape. For our second experiment dealing with solids, we'll try something different. Only this time, it might not be so easy to definitely say that a substance really is a solid. For this experiment you'll need a small plastic mixing bowl, a mixing spoon, cornstarch, and water. Out about a quarter cup of the cornstarch to the bowl and pour in about a quarter cup of water. Mix it well. Keep adding cornstarch or water until the mixture looks glossy but is firm to the touch. Touch it with your finger in several places. How would you say it feels? Take the mixing bowl and tilt it to one side without spilling it. What happens? Remember what we said about liquids and how they flow and change shape? Does this material that looks and feels like a solid behave like a liquid? Now, roll some of the mixture into a ball and hold it on your hand. What happens to it? Some materials like this cornstarch and water mixture can act more like a solid when treated in a certain way and more like a liquid when treated in another way. When you pushed it or rolled it into a ball, it acted like a solid. But when you leave it alone on your hand, it forms into something that acts more like a liquid. Why is that? Well, the water, a liquid, and the cornstarch, a solid, mix together to form something called a colloid. A colloid is a material that consists of one substance suspended within another. The suspended material is comprised of particles so small that they don't sink to the bottom of the second substance. Together, the two materials display properties that are different than those of their separate parts. When you add something like sand to water, you get two different things that stay separate. In other words, the sand, which is a solid, and the water, which is a liquid, keep their individual states of matter. A solution is made when a solid dissolves completely in a liquid, like this drink powder. For our last experiment, we'll need the following items. Shaving cream, paper towels, and a penny. First, place a small amount of shaving cream on the paper towel and observe the shaving cream. Would you call it a solid, liquid, or gas? One of the characteristics of a solid is that it keeps its shape without being in a container. But would you say the shaving cream is a solid? Why? Or why not? Now, take the penny and carefully place it on the top of the shaving cream. What happens? When you observe the shaving cream, did you change your mind about whether it's a solid, liquid, or gas? Rub some of the shaving cream on your finger. What state of matter does it feel like? Now take the shaving cream blob and leave it out overnight. What's happened? How has it changed? Once again, we've seen that it's not always so easy to definitely say that a substance is a solid, liquid, or gas. When we were working with the cornstarch and water mixture, it acted like a solid when treated one way and more like a liquid when treated another way. The shaving cream seems to have unusual states of matter as well. That's because the shaving cream is a liquid soap with lots of gas bubbles in it. The gas makes it thick and frothy so it keeps its shape and supports light objects like a solid would. When you allow the liquid from the shaving cream to evaporate, all that's left is a very light and thin solid soap and the space where the gas bubbles once were. Today, we learned some of the principles of the three states of matter, solid, liquid, and gas. We learned that solids are different than liquids or gases. They are matter with a volume and a shape. However, liquids flow and take the shape of the container they are in. A gas doesn't matter with relatively low density and no shape at all like the air we breathe, which is a mixture of gases. Thanks for watching and I hope you continue to learn more about solids, liquids, and gases in school and on your own.