Access Point #: SC.4.P.9.Pa.1

In this lesson, students are shown the difference between physical and chemical changes by dissolving and crushing seltzer tablets. Students learn to recognize that physical changes involved changes in size, shape, or texture, while chemical changes involve the formation of a new substance.

Type: Lesson Plan

In this series of 10 investigations, students gain experience with the evidence of chemical change - production of a gas, change in temperature, color change, and formation of a precipitate. Students begin by observing that similar-looking powders can be differentiated by the way they react chemically with certain test liquids. Students then use their chemical tests and observations to identify an unknown powder and, in a follow-up activity, to identify the active ingredients in baking powder. Students continue to explore chemical change by using a thermometer to observe that temperature either increases or decreases during chemical reactions. Then they control these reactions by adjusting the amount of reactants. In another set of activities, students use the color changes of red cabbage indicator to classify substances as acids or bases, neutralize solutions, and compare the relative acidity of two different solutions. Students conclude the investigation by comparing a precipitate to one of the reactants that formed it. Students see that a new substance was created during the chemical reaction. Information and questions about photosynthesis and cellular respiration are included as examples of chemical changes on pages 316-318 of this resource.

Type: Unit/Lesson Sequence