1. Matter, and more!

2. Matter  Anything that has MASS and takes up SPACE

3. How is Matter classified?  1) Pure Substances  2) Mixtures

4. 1) Pure Substances  Composition remains the same, does not depend on a sample = Fixed composition  Homogenous—same throughout.  Example: Compound (NaCl) or Element (Fe)

5. 2) Mixtures  2+ substances combined together  Substances do not change their properties or name.  Able to be separated, not chemically combined.  Possess a combination of properties based on the substances present.

6. Types of Mixtures 1) Homogenous  Uniform composition  Also known as “ true solutions ”  Ex. Salt-water 2) Heterogeneous  No uniform composition  Can easily see the different components of the mixture  Ex. Italian dressing

7. Mixture Types---More Detail  True Solution  What we normally think of as a “solution”  Homogenous  Solute/solvent completely dissolved

8. Mixture Types (cont.)  Suspension  Heterogenous  Solute partly disperses but settles out of solvent, does not stay dissolved/equally dispersed  Little interaction between solute and solvent  Observable particles Ex. Sand and water, soil and water

9. Mixture Types (cont.)  Colloids  Defined based on dispersed particle size, particles cannot be seen  Properties  Cloudy appearance  Tyndall effect  Preference for specific cations/anions  Categorized based on particle and medium states of matter  Emulsion  Aerosol

10. Tyndall Effect  Scattering of light as it passes through a colloid  Helps distinguish between true solutions and colloids

11. How are mixtures separated?  Thin-Layer Chromatography  Filtration  Centrifuge

12. Identify whether a substance is pure/mixture and homogenous/heterogeneous.  1) Salad  2) Chocolate milk  3) Element  4) Kool-Aid  5) Vegetable soup  6) Ca  7) IV fluids  8) Duke’s mayonnaise  9)Blood  10) Trail Mix

13. Properties of Matter 1) Chemical  Ability to go through changes resulting in a different substance  The substance is no longer the same, different identity  Evidence of chemical reaction: color change, precipitate forms, gas formation, and/or temperature change  Ex. Burning 2) Physical  Observed or measured property  Substance identity is not changed  Ex. melting point, boiling point, density

14. Practice

15. Classify each change as either chemical or physical. 1) Gasoline in your engine burns as you start the car. 2) Distilled water 3) Rust on a nail 4) Glow sticks 5) Medicine crushed into a powder

16. Extensive vs. Intensive Properties  Extensive Property  Dependent on the quantity of matter  Ex. Mass  Intensive Property  Does NOT depend on matter quantity  Ex. Density

17. Homework  Chemical vs. Physical Changes Worksheet