Part B : Changes in Matter Explanations 1. This is condensation that forms on the outside of a glass. 1) How did this condensation form? Write or draw your explanation. Be sure to include a description of the heat energy involved. (If you draw your explanation, you can take a picture and add it to this spot.) 2) Is this an example of a physical or chemical change? Why do you know that it is this type of change? 3) The water on the outside of the glass seems to appear from nowhere. Where does the water actually come from? How does this show conservation of mass? 2. In this picture, an Alla-Seltzer tab is placed in water. Carbon dioxide bubbles are being released. . Is this a chemical or physical change? How do you know? . This is the chemical equation for what is occurring in the picture. What number belongs in the blue box? How did you gure this out? - Explain how the chemical equation shawls conservation of mass. - How would you explain to a fth grader what's going on at a molecular level in the AlkaSeltzer tab? - How could you create an investigation to show that conservation of mass occurs when an AlkaSeltzer tab is placed in water