Objects can be described by the properties of the materials from which they are made, and those properties can be used to separate or sort a group of objects or materials. Light, heat, electricity, and magnetism Light travels in a straight line until it strikes an object. Magnets attract and repel each other and certain kinds of other materials. Earth and Space Science Properties of earth materials Earth materials include solid rocks and soils. The varied materials have different physical and chemical properties, which make them useful in different ways, for example, as building materials and as resources for fuel.
Earth materials provide many of the resources that humans use.
Fossils provide evidence about plants and animals that lived long ago and the nature of the environment at that time. The surface of the earth changes. Some changes are due to slow processes, such as erosion and weathering, and some changes are due to rapid processes, such as landslides, volcanic eruption, and earthquakes. People have always had questions about their world. Science is one way of answering questions and explaining the natural world.