Properties of Matter

1. Properties of Matter Chapter 15 Section 2

2. Classify these PROPERTIES as physical or chemical. If you aren’t sure, guess! • Color ______________________________ • Flammability ______________________________ • Odor ______________________________ • Shape ______________________________ • Taste ______________________________ • Density ______________________________ • Melting Point ______________________________ • Tendency to Rust ______________________________ • Reacts with light ______________________________ • Boiling Point ______________________________ • Volume ______________________________ • Malleable ______________________________ • Mass ______________________________ • Magnetism ______________________________ • Ductile ______________________________ • Ability to dissolve ______________________________

3. Physical Properties • A characteristic of a material that you can observe without changing the identity of the substance that makes up the material

4. Physical Properties • Physical Properties can be related to: • Appearance • What color is the item? • What shape is the item? • What is the item’s phase of matter? • Behavior • Does it attract a magnet? i.e. iron • Can it be pulled into wires (ductile)? i.e. copper • Can it be hammered into sheets (malleable)? i.e. gold • At what temperature does it boil (boiling point)?

5. Physical Properties • Physical properties can be used to separate substances in a mixture • How would you separate a mixture of iron, sand, and salt using physical properties? • http://www.youtube.com/watch?v=Rc9o2tbOxxY

6. Chemical Properties • A characteristic of a material that indicates whether it can undergo a certain chemical change • The result of the chemical change would be the production of a new substance • Some examples: • tendency of something to burn (flammability) • i.e. lighter fluid, paint thinner • tendency of something to react with light • i.e. medicines that come in dark bottles like hydrogen peroxide (H2O2)

7. Try this Again! Classify these PROPERTIES as physical or chemical. If you aren’t sure, guess! Physical • Color ______________________________ • Flammability ______________________________ • Odor ______________________________ • Shape ______________________________ • Taste ______________________________ • Density ______________________________ • Melting Point ______________________________ • Tendency to Rust ______________________________ • Mass ______________________________ • Boiling Point ______________________________ • Volume ______________________________ • Malleable ______________________________ • Reacts with light ______________________________ • Magnetism ______________________________ • Ductile ______________________________ • Ability to dissolve ______________________________ Chemical Chemical Physical Chemical Physical Physical Chemical Physical Physical Physical Physical Chemical Physical Physical Physical

8. Classify these CHANGES as physical or chemical. If you aren’t sure, guess! • Evaporating water __________________________ • Rust on an iron nail __________________________ • Baking cookies __________________________ • Dissolving salt in water __________________________ • Hammering Aluminum into a sheet _________________ • Cooking scrambled eggs _________________________ • Burning a marshmallow __________________________ • Melting an M&M in your mouth ____________________ • Alka seltzer in water __________________________ • Raising bread dough __________________________ • Cutting an apple __________________________

9. Physical Change • A change in the size, shape, state of matter, etc. that does not change the identity of a substance • A phase change is a physical change even though energy may be removed or added to the substance • In the new state of mater, the substance is still made of the same components, the atoms just have more or less energy • i.e. if liquid water evaporates, it becomes water vapor if water vapor condenses, it becomes liquid water

10. Phase Changes SOLID Freezing, Hardening, Solidifying Sublimation Melting Liquefying Deposition LIQUID GAS Evaporation Boiling Condensing

11. Distillation • Distillation is a process that takes advantage of physical properties and physical changes to separate mixtures • If two substances have different boiling points (temperature at which they boil), they can be separated. • The mixture is heated slowly until it begins to boil. • The vaporsof the liquid with the lowest boiling point form firstand are condensedand collected. • If the other substance also needs to be collected, then the temperature is increased until the second liquid boils, condenses, and is collected

12. Distillation Set-Up

13. Chemical Change • The change of one substance into a new substance (chemical reaction) • A chemical change alters the original chemical make-up of the substance

14. Indications of a Chemical Reaction How can you tell if a chemical change has taken place? • ENERGY Evolution of heat, light, and/or sound (sometimes heat can be absorbed too) • GAS A gas is produced, bubbles (effervescence) • PRECIPITATE When solid particles form from 2 liquids • COLOR – Unexpected Color change (i.e. clear liquid + clear liquid  purple liquid)

15. Try this Again! Classify these CHANGES as physical or chemical. If you aren’t sure, guess! • Evaporating water __________________________ • Rust on an iron nail __________________________ • Baking cookies __________________________ • Dissolving salt in water __________________________ • Hammering Aluminum into a sheet _________________ • Cooking scrambled eggs _________________________ • Burning a marshmallow __________________________ • Melting an M&M in your mouth ____________________ • Alka seltzer in water __________________________ • Raising bread dough __________________________ • Cutting an apple __________________________ Physical Chemical Chemical Physical Physical Chemical Chemical Physical Chemical Chemical Physical

16. Law of Conservation of Mass • Matter is neither created nor destroyed during a chemical change (reaction) • The mass of the substances present beforethe chemical change equalsthe mass of the substances that remain afterthe change Example Is burning wood a physical or chemical change? After a log burns, only ashes remain. Where do you think the rest of the mass went? Chemical change - Combustion Some mass left as solid particles in the smoke, some mass left as gas (CO2)

17. Example of Chemical Changes • What color was the Statue of Liberty when it was dedicated in 1886? • NOT green! • The Statue of Liberty is made of copper • The copper at the surface has undergone a chemical change as the result of exposure to air and water. She is now covered in patina which is green!