1. CHEMICAL VS. PHYSICAL PROPERTIES

2. SO FAR...  We have defined chemistry:  The study of matter and its reactions  What is matter?  What is a reaction?

3. FORMAL DEFINITION  The formal definition of matter is:  Anything that has mass and takes up space  We are going to go over some ways we describe matter

4. PHYSICAL PROPERTIES  Physical property: a characteristic of matter that can be observed without changing the composition of matter  Density  Color  Odor  Hardness  Melting point  Boiling point

5. CHEMICAL PROPERTIES  Chemical property: ability to combine with or change into one or more other substances  How does it react with other substances

6. EXAMPLE: COPPER  Physical properties  Reddish brown, shiny  Easily shaped  Good conductor of heat and electricity  Density = 8.92g/mL  Melting point = 1085°  Boiling point = 2570°  Chemical properties  Forms green copper carbonate when in contact with moist air  Forms a deep-blue solution when in contact with ammonia

7. PHYSICAL CHANGE  Physical change: a change in a substance that does not change the composition of the substance  Boiling  Melting  Breaking/bending

8. CHEMICAL CHANGE  Chemical change: a change that produces a new substance  Explosion  Rust  Corrosion  Burn

9. PHASE CHANGES  We’ve already discussed one type of physical property – DENSITY  We are now going to focus on an important type of physical change  PHASE CHANGES

10. PHASES OF MATTER  Phase: form of matter.  Solid: phase of matter w/ a definite shape and volume.  Liquid: phase of matter w/ definite volume, but no shape.  Gas: phase of matter that has no definite shape or volume

11. HOW DOES MATTER CHANGE PHASES?  Evaporation: change from a liquid to a gas.  Condensation: change from a gas to a liquid.  Freezing: change from a liquid to a solid.  Melting: change from a solid to a liquid.

12. WHAT DO THE PARTICLES LOOK LIKE?  For each state of matter, the particles that make up the substance behave differently.  In your notes, you will draw how the molecules are arranged for the following:  Solid  Liquid  Gas

13. WHAT HAPPENS IN A PHASE CHANGE  Next, in your notes, I want you to write a paragraph about how the molecules behave when you change from one state of matter to another:  Solid  Liquid  Liquid  Gas

14. PHASE CHANGE DIAGRAM  This week, we are going to create a phase change diagram showing how temperature behaves when we change states of matter

15. SAMPLE DATA Time (min)Temperature(°C) 0 (ice)-22 1-15 2-8 3 (melting) -2 40 5 0 6-1 70 8 (water)5 912 1024 1138 Time (min)Temperature(°C) 1251 1368 1485 15 (boiling)99 16100 1799 18101 19100 20100 22101 23 (steam)110 24122 25138 26155