Most substances exist in one of three of matter. Whenever a change occurs, the substance has new . This happens because the are arranged differently. Each pure substance has a melting point, or temperature at which a changes into a . Each also has a boiling point at which the liquid changes into a . The process by which a liquid slowly turns into a gas is known as . The temperature at which a liquid changes into a solid is known as the point. Most materials , or become smaller, as they get cooler. They , or become larger, as they get hotter.
