6th Grade Science / Lesson 4 - Heat Changes Matter
Heat Changes Matter
What will we be learning today?
How Can Heat Change Matter?
How can heat change an ice cube? What happens to a glass of water left in sunlight? Solid ice can change to liquid water. Liquid water can change to a gas-water vapor. A solid can become a liquid, a liquid can become a gas. It works in reverse, too. When a substance changes from solid to liquid or liquid to gas, we say it is changing its state. The state of matter of a substance at room temperature is another important physical property. At room temperature the oxygen in the air is a gas, while water is a liquid, and steel is a solid. The temperature at which a substance changes from a solid to a liquid is called the melting point. This temperature is different from one substance to the next. In the same way, each substance has its own boiling point-the temperature at which it turns from a liquid to a gas. Like density melting points and boiling points are physical properties that can help to tell substances apart. When a substance is heated in a certain state, its particles tend to spread out as they move faster. As a result the substance expands. This is what makes the liquid in a thermometer rise when it is placed in a hot material. The rate at which different materials expand is a physical property. For example, aluminum expands about 48 times more than quartz for the same change in temperature. Let's Review What We Learned Today!