WA.4. Physical Science
PS2. Matter: Properties and Change
4-5.PS2. States of Matter: In prior grades students learned to identify different physical properties of matter and to realize that an object may be made from several different types of materials. In grades 4-5 students learn that a given substance may exist in different states-solid, liquid, and gas-and that many substances can be changed from one state to another. This understanding of matter lays the foundation for later explanations of matter in terms of atomic theory.
4-5.PS2A. Students know that substances can exist in different physical states-solid, liquid, and gas. Many substances can be changed from one state to another by heating or cooling.
4-5.PS2A.1. Students are expected to explain that water is still the same substance when it is frozen as ice or evaporated and becomes a gas.