In this topic you will learn about three forms of matter: solids, liquids, and gases. Each of these three forms of matter takes up space and has mass.
A solid is matter that has a definite shape and volume. Definite means that it stays the same. If you put a sneaker in a container, it stays the same shape in the container as it had outside the container. Its volume stays the same, too. In a solid, the particles of matter are packed closely together. They form a certain pattern which gives the solid its definite shape.
Juice is an example of a liquid. A liquid is matter that has a definite volume, but not a definite shape. A liquid takes the shape of the container it is in. The particles in a liquid are close together but do not form a certain pattern. Particles in a liquid have more energy than particles in a solid. Particles in a liquid are able to slide past one another. That is why liquids change their shape.
Another form of matter is gas. A gas is matter that has no definite shape or volume. The particles in a gas spread out to fill a large container or squeeze together to fit into a smaller container. Gases take the shape of the container they are in. Air is made of gases.
Matter can change and still be the same type of matter. When you slice an orange, the orange may look different, but it is made from the same particles as before it was cut. Matter can also change form and still be the same type of matter. You can find water in the form of a solid, a liquid, or a gas.
When you mix different types of matter together, you may get a mixture. In a mixture, each part has the same properties in the mixture that it has outside the mixture. Air is a mixture of gases. Salad dressing is a mixture of oil and vinegar. One special type of mixture is a solution. A solution is formed when one or more types of matter are spread evenly throughout another kind of matter.