1. Ch. 15 – Physical & Chemical Changes Lesson 1 – Energy & Physical Change

2. When matter undergoes a physical change, its chemical makeup does what? Remains the same

3. Which would have more volume – one pound of hot food fresh off the stove, or one pound of the same leftover food in the refrigerator? Why? The hot food would have more volume, because, in general, substances expand when heated and contracted when cooled.

4. Look at the graph on the bottom left hand side of the page, E52, at constant pressure what happens to volume of the gas as its temperature is increasing? The graph shows that volume increases as temperature increases.

5. You pump air into a basketball using a bicycle pump. Predict the changes in gas pressure inside the basketball. Why does this happen? The pressure of the air increases because more air molecules are in the basketball.

6. When a substance, such as water, is frozen its particles stop moving. Is this a true statement? No, particles in solid & frozen substances are always moving. They just move less.

7. The melting point of a substance occurs at the same temperature as its freezing point.

8. Which must change in order for a substance to transform a gas to a liquid? Temperature

9. At a substance’s _____________ ____________, liquid turns to gas.

10. Lesson 2 – Energy & Chemical change

11. A marshmallow is cooked over an open flame. What observable clue tells you that the marshmallow is undergoing a chemical change? The outer surface of the marshmallow has changed color.

12. A firefly makes light in its body without electricity. Describe what must be happening inside the firefly’s body to make this light The firefly creates light through a chemical reaction, similar to the way a glow stick gives off light

13. During photosynthesis, the energy of sunlight is absorbed. Therefore, photosynthesis is classified as a(n) ___________________ chemical reaction.

14. In most cases, reactions that involve burning, flames, or explosion(s) are exothermic reactions. Give examples of this type of reaction. Camp fires Fireworks respiration

15. Lesson - 3 Chemical Reactions

16. Chemical Reactions can be classified as what? Synthesis Decomposition Combustion

17. The equation for the decomposition of water is shown on pg. E71 How does this equation illustrate how matter is conserved during a chemical reaction? According to the law of conservation of matter, the total mass of the substances in a chemical reaction does not change, no matter what new products form. In this reaction, there are 4 hydrogen atoms & 2 oxygen atoms on each side of the arrow

18. For the test you will need to study Workbook section 15.2- question 2 Definitions –Volume –Temperature –Endothermic reaction –Exothermic reaction –Conservation of matter