2. H 2 O(s) H 2 O(l) Is it still the same substance? Have the physical properties changed?

3. 2C 20 H 42 (s) + 61O 2 (g) 42H 2 O(g) + 40CO 2 (g) In the presence of a flame: Is it still the same substance? Have the physical properties changed?

4. 2C 20 H 42 (s) + 61O 2 (g) 42H 2 O(g) + 40CO 2 (g) If the flame cools down: Does the candle come back? ?

5. 2C 20 H 42 (s) + 61O 2 (g) 42H 2 O(g) + 40CO 2 (g) If the flame cools down: The candle does not come back by itself. X In this chemical reaction, the atoms were rearranged. This change is irreversible. Therefore the substance has undergone a chemical change

6. What is a physical property? A characteristic that can be observed or measured without changing the sample’s composition

7. What is a Chemical Property  The ability of a substance to combine with or change into one or more other substances

8. What Defines a Physical Property  Change that alters a substance without changing its composition  Examples- I can cut a log in half. Have I actually changed the wood?

9. What Defines a Chemical Property  Process that involves one or more substances changing into new substances

10. Indications that a CHEMICAL change has Occurred  Formation of a gas  Formation of a solid  Color change  Temperature/energy change  Odor/smell

11. Extensive vs Intensive Properties  Extensive  Dependent upon the amount of substance present  Ex. Mass, length, volume  Intensive  Independent of the amount of substance present  Ex. Density, hardness, temperature **Chemical Properties are ALWAYS intensive**

12. Qualitative vs Quantitative  Quantitative data is information about quantities; that is, information that can be measured and written down with numbers. Some examples of quantitative data are your height, your shoe size, and the length of your fingernails  Qualitative data is information about qualities; information that can't actually be measured. Some examples of qualitative data are the softness of your skin, the grace with which you run, and the color of your eyes.

13. Scenarios  The age of your car.  The number of hairs on your knuckle.  The softness of a cat.  The color of the sky.  The number of pennies in your pocket.