Physical Science PS2 States of Matter

EALR 4: Physical Science Big Idea: Matter: Properties and Change (PS2) Core Content: 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. Content Standards are located at the top of each slide. Performance Expectation slides for each content standard follow and are located on the bottom of slides highlighted in green.

TEACHER RESOURCES

4-5 PS2A 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.

Performance Expectations PS2A: Explain that water is still the same substance when it is frozen as ice or evaporated and becomes a gas.

4-5 PS2B Air is a gas. Air fills a closed container completely. Wind is moving air. The wind blows these flags. Air fills this balloon. The wind is able to blow the branches on these trees.

Performance Expectations PS2B: Explain that a balloon expands when you blow air into it because blowing air into the balloon creates greater air pressure inside the balloon than outside the balloon.

Performance Expectations PS2B: Describe how the wind can move things (e.g., wind can move the branches of trees when it blows and moves sailboats through the water).

4-5 PS2C The total amount of matter is conserved (stays the same) when it undergoes a physical change such as when an object is broken into tiny pieces, when a solid is dissolved in a liquid, or when matter changes state (solid, liquid, gas).

Performance Expectations PS2C: Explain that dissolved substances have not disappeared, and cite evidence to determine that the substance is still there (e.g., sprinkle sugar on cereal, add milk, and you can taste it even though you can no longer see the sugar).

Performance Expectations PS2C: Predict that the weight of a sample of water will be nearly the same before and after it is frozen or melted. Explain why the weight will be almost the same.

Performance Expectations PS2C: If an object is weighed, then broken into small pieces, predict that the small pieces will weigh the same as the large piece. Explain why the weight will be the same. If this toy is broken, the pieces should weigh about the same as the unbroken toy.