4.2.5b classify materials according to states of matter such as solids, liquids, and gases Properties can be used to separate or sort a group of objects or materials. Some common materials, such as water, can be changed from one state to another by heating or cooling. Electricity in circuits can produce light, heat sound, and magnetic effects. Electrical circuits require a complete loop through which an electrical current can pass. Magnets attract and repel each other and certain kinds of other materials.
Light travels in a straight line until it strikes an object.
Light can be reflected by a mirror, refracted by a lens, or absorbed by the object. The position of an object can be described by locating it relative to another object or the background. An object's motion can be described by tracing and measuring its position over time. The position and motion of objects can be changed by pushing or pulling. The size of the change is related to the strength of the push or pull.