Unlike in the lower atmosphere, Ozone plays a positive role in the upper atmosphere. Scientists monitor ozone levels to provide real time data on air quality to the public. Canyonlands National Park also monitors ozone at ground level. Car exhaust, the result of a chemical change in fuel, is a major contributor of ozone to the lower atmosphere. High levels of ozone in the lower atmosphere can cause human health problems and can contribute to the greenhouse effect. Ozone is an invisible gas made of 3 oxygen atoms. Burning a piece of paper would be a chemical change, as would baking a cake. At the end of a chemical change, you have a new substance.
Chemical changes are those where one or more substances are combined to produce a new substance. For example, chopping up a carrot or ice melting into water are both physical changes. Physical changes are those in which the shape, size, or state of the matter changes, but the substance is still essentially the same. Matter can exist as a solid, liquid, or gas (or plasma) and can change in many ways. Air, water, rocks, trees, stars, and animals all consist of matter. Everything that has mass and volume, no matter how small, is made of matter. Emphasize whether a new substance is or is not created by the formation of a new substance with different properties. Standard 5.2.3 Plan and carry out investigations to determine the effect of combining two or more substances. Emphasize making observations of changes supported by a particle model of matter. Standard 5.2.1 Develop and use a model to describe that matter is made of particles on a scale that is too small to be seen. Whether a change results in a new substance or not, the total amount of matter is always conserved. When two or more different substances are combined a new substance with different properties may be formed.
Substances have specific properties by which they can be identified. Matter is made of particles that are too small to be seen but still exist and can be detected by other means. Strand 5.2: PROPERTIES AND CHANGES OF MATTER All substances are composed of matter. Utah Science with Engineering Education Standards: Strand 5.2: Properties and Changes of Matter:Įssential Question: What physical and chemical changes in matter can be observed in nature? Grade Level: Upper Elementary: Third Grade through Fifth Grade Subject: Science State Standards: Utah Science Standards
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