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E1: Describe how the physical properties of objects sometimes change when on object chemically combines with another.

Curriculum Organizing Questions	What are the properties of the substances before? Of the substance(s) after reacting?
Elaboration	When carefully observed, described, and measured, the properties of objects, changes in properties over time, and the changes that occur when materials interact porvide the necessary precursors to the later introduction of more abstract ideas in the upper grade levels. NSES essay p.126
Specific Ideas	When a new material is made by combining two or more materials, it has properties that are different from the original materials. For that reason, a lot of different materials can be made from a small number of basic kinds of materials.Benchmarks 4D4 Substances react chemically in charasteristic ways with other substances to form new substances (compounds) with different characteristic properties.SFAA p.47 Objects have many observable properties, including size, weight, shape, color, temperature, and the ability to react with other substances. NSES B1a
Developmental & Instructional Implications	Although in science the term "chemical change" is reserved for processes in which the reacting chemical substances disappear and other (new) substances appear, several studies have found that children often use the term "chemical change" to encompass changes in physcial state and other physical transformations, especially when the color of a substance alters.
Examples

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