1. Describing Matter
Section 1

2. Points to Cover Give Examples of matter’s different properties
Describe how density is used to identify different substances
Compare physical and chemical properties
Explain what happens to matter during physical and chemical changes

3. Physical Property
Any property that can be observed or measured without changing the identity of the matter
Examples: Color, Odor Volume

4. More Physical Properties
Thermal Conductivity
State
Malleability
Ductility
Solubility
Density

5. Density The amount of matter in a given space D=M/V
Density is expressed in g/cm3 and g/mL

6. Density
Density is useful in identifying a substance because of two reasons
(1) it is the same at a given temp and pressure
(2) density is usually different for all substances

7. Chemical Properties
Chemical properties describe a substance based on its ability to change into a new substance with different properties
Examples: Flammability, Reactivity

8. Chemical Vs. Physical Properties
Characteristic properties of a substance are always the same whether the sample you’re observing is large or small

9. Physical Changes
A change that affects one or more physical properties of a substance
Example: water vapor condensing from a gas to a liquid. It’s state and density change.

10. Physical Changes Most physical changes can be undone
Example: Ice melts to form water, however you can freeze that water again to form ice

11. Chemical Changes
Occurs when one or more substances are change into entirely new substances with different properties
The new substance will have a new chemical composition.
Example: Burning a piece of wood, milk souring

12. Chemical Changes
Since a new substance is formed, a chemical change cannot be undone unless another chemical change occurs.

13. Review