1. Today’s Starting Point
1. What is an intensive property of matter? List two examples of intensive properties.
2. What is an extensive property of matter? List two examples of extensive properties.
Do not depend upon the amount of matter present; color, density
Do depend upon the amount of matter present; mass, volume

2. Today’s Starting Point
3. Compare these two elephants. What would be an intensive property of the elephants? What would be an extensive property of the elephants?

3. Pure Substances and Mixtures

4. By the end of the class period today I will be able to…
Identify a piece of matter as an element, compound, homogeneous, or heterogeneous mixture based upon its properties

5. Pure Substances
Composition is the same throughout and does not vary from sample to sample.
CANNOT be broken down by physical changes
Can be an element or compound.

6. Element Definition: substances in their simplest forms
Cannot be broken down by a physical or chemical change
Found on the periodic table
Made up of one type of atom

7. Examples of Elements: Hydrogen Carbon Lithium Gold
What are two other examples of elements not listed above? What do all elements have in common?

8. Compound
Definition: substance formed by the chemical combination of two or more elements
can be broken into simpler substances by a chemical change +
= Compound

9. Law of Definite Proportions
A compound is always composed of the same elements in the same proportions.
In other words, Carbon Dioxide (CO2) is always composed of 1 atom of C and 2 atoms of O.
If there are different amounts of carbon or oxygen, it is no longer carbon dioxide.

10. More Examples of Compounds

11. Mixture
Definition: two or more pure substances (elements or compounds) that are mixed together but NOT joined chemically
NOT a pure substance
Examples: The air we breath, gasoline for cars, the sidewalk on which we walk

12. Homogeneous Mixtures Uniform in composition and appearance
Same proportion of components throughout
Consists of two or more substances in the same phase
Also called solutions

13. Heterogeneous Mixtures
variable appearance and composition

14. Raise ‘em Up!
Look at the following example and with your partner determine if it is a heterogeneous mixture, homogeneous mixture, element, or compound
Chicken noodle soup
Strawberry banana smoothie
Coca-cola
Purified water
Helium

15. Heterogeneous Mixture
Chicken Noodle Soup
Heterogeneous Mixture

16. Pure Water
Compound

17. Tap Water
Homogeneous Mixture

18. Pure Gold
Element

19. Coca-Cola
Homogeneous Mixture

21. Kool Aid has mass and takes up space

22. Can be separated by allowing water to evaporate

23. Same composition throughout