Attention Getting Question:
How can matter change its state? To find out, you must learn more about the states of matter.
Matter is anything that has mass and takes up space. There are three states, or forms, of matter: solids, liquids, and gases. Scientists have learned that all matter is made of tiny particles. The particles in matter are too small to see, but scientists know they are always in motion. The way the particles are arranged and how they move determine the state of a substance.
The particles in solids are tightly packed together. They stay in one place, but they vibrate. Solids hold a definite shape because the particles do not move past each other. The particles in liquids also vibrate, but they move by gliding past each other. This allows liquids to flow and take the shape of their container. Most of the time the particles in liquids are not as tightly packed as they are in solids; however, water is an exception. The particles in water are closer together than in ice. Gases have particles that are spread out, but not in any particular arrangement. The particles in gases move easier and faster than those in solids or liquids. This allows them to expand to fill whatever space is available. It is also why gases do not have a shape or volume of their own.
Matter changes states by adding or taking heat away. The melting point of a substance is the temperature at which a solid changes into a liquid. The freezing point of a substance is the temperature at which a liquid changes into a solid. Both the melting point and the freezing point of a substance are the same temperature for a particular substance. The boiling point of a substance is the temperature at which a substance changes from a liquid to a gas. Condensation occurs when a gas turns into a liquid. Each substance has a certain temperature at which it will change states.
Let’s think about how water changes states. As water gets colder, the particles within it will slow down. The freezing point of water is 0°C or 32°F. The water becomes ice at this point and the particles will stop gliding past each other and will only vibrate in place. If we leave ice in a container at room temperature, the solid ice will eventually turn back into liquid water because the ice will melt. If we add heat by placing a glass beaker of water on a hot plate, the water will reach its boiling point or the temperature at which bubbles of gas form under the surface of a liquid. At this point, since heat was added, the particles have energy to move faster. The boiling point of water is 100°C or 212°F. So you see, matter changes states by increasing temperature or decreasing temperature.
Matter changes states by adding or taking away heat. The melting point is the temperature at which a solid changes into a liquid. The freezing point is the temperature at which a liquid changes into a solid. The boiling point of a substance is the temperature at which a substance changes from a liquid to a gas. Condensation occurs when gases turn into liquids. Scientists observe the changes in matter and you can, too.