The document discusses chemical properties of matter including reactivity and comparing physical and chemical properties. It notes that a chemical property can only be observed through a chemical change that alters the substance. Some signs that a chemical change has occurred include changes in color, odor, gas production, sound, light, or temperature. It also states that chemical changes tend to be irreversible.

1. Chapter 3, Sec 3 Chemical Properties Page 91 10/04/10

2. Warm Up 10/01/10 An object is measured using the displacement method. The graduated cylinder measures 25mL of water before the object is added. The cylinder measures 50mL after the object is added. What is the volume of the object in cm 3 ?

3. Chemical Properties Property of matter that describes a substance’s ability to participate in a chemical reaction.

4. Reactivity The ability of a substance to change into one or more new substances. Flammability Wood has flammability (ability to burn) Ash does not have flammability

5. Comparing Physical and Chemical Properties Physical property – can be observed without changing substance. Density, thermal conductivity Chemical property – substance needs to change to observe a chemical property. Wood needs to burn to know its flammable.

6. Signs of a chemical change: If there is a change in the following it is most likely a chemical reaction: Color Odor Fizz and foam (creating gas) Sound Light Sudden heat (or cold)

7. Irreversible You can not un-burn a piece of paper, or un-rust a nail. (not easily)

8. Practice Chemical or Physical change? ___ Iron rusts ___ Sugar dissolved in water ___ Burning match ___ Cube of ice that melts ___ Water changing into steam ___ Sour milk

9. Homework Section Review: page 95, Numbers 1-5 Read Chapter 3: Section 3