1. Section 1: Composition of Matter

2. Warm-up: Think of that air you are breathing in right now.
What are some components of air?
Why might air be referred to as a mixture?

3. Learning Goals Define substances and mixtures.
Identify elements and compounds.
Compare and contrast solutions, colloids, and suspensions.

4. Matter Matter: anything that has mass and takes up space
All matter can be divided into substances and mixtures.

5. Substances Substances: type of matter with a fixed composition
can be either elements or compounds.

6. Elements
Elements: substance built from all atoms of the same identity; cannot be broken down into simpler parts
Examples: Hydrogen (H), oxygen (O), carbon (C)

7. Elements All elements are listed on the periodic table.
There are about 90 naturally occurring elements.
Approximately 20 have been made in laboratories.

9. Compounds
Compounds: substance in which two or more atoms are combined in a fixed proportion

10. Compounds
Common examples: water (H2O) or sugar (C6H12O6)

11. Mixtures
Mixture: material made of two or more substances that can be separated by physical means
Mixtures can be heterogeneous or homogeneous

12. Heterogeneous Mixtures
Heterogeneous mixture: a mixture in which the different materials can be distinguished easily

13. Heterogeneous Mixtures
Examples: salad, granite, dry soup mix

14. Homogeneous Mixtures
Homogeneous mixture: contains two or more gaseous, liquid, or solid substances blended evenly throughout
Examples: vinegar (acetic acid and water), iced tea, fog, smoke

15. Homogenous Mixtures
Homogeneous mixtures can be described as solutions or colloids

16. Solutions
Solution: homogeneous mixture with particles so small that they cannot be seen with a microscope and will never settle to the bottom of the container
Examples: lemonade, salt water

17. Solutions Made up of two parts: solute (what is dissolved)
solvent (what does the dissolving)

18. Colloids
Colloids: type of mixture with particles that are larger than those in solutions but are not heavy enough to settle out
Examples: paint, fog, smoke

19. Colloids
Colloids are detected using the Tyndall effect where you pass light through the substance. The particles in the colloid will scatter the light.

20. Suspensions Some mixtures are neither solutions nor colloids
Suspension: heterogeneous mixture containing a liquid in which visible particles settle.
Examples: pond water, Italian dressing

21. Suspensions

23. Check-in:
Why might it be easy to confuse a compound and a homogeneous mixture?