1. Unit 2 – Matter and Energy Mrs. Callender

2. Lesson Essential Question: What are the differences between chemical and physical changes?

3. PHYSICAL CHANGE A change of matter from one form to another without a change in chemical properties.

4. The form or appearance has changed, but the properties of that substance are the same (i.e. it has the same melting point, boiling point, chemical composition, etc.)

5. CHEMICAL CHANGE A chemical change occurs when a substance changes into something new. There are four types of chemical changes.

6. 1. Formation of a Precipitate Precipitate: solid that forms when two products are formed in a chemical reaction and one is insoluble in the other.

7. 2. Color Change Dilution: when color becomes lighter. This is NOT a chemical change. Color change must be obvious. Ex. Red to Green etc.

8. 3. Gas production Bubbles will form during the reaction.

9. 4. Heat Exchange Exothermic – Temperature increase. Bromine + Al foil yields HEAT

10. 4. Heat Exchange Endothermic – Temperature decrease.

11. What are the differences between Physical Properties Chemical Properties AND of elements and compounds?

12. PHYSICAL PROPERTIES of pure substances

13. CHEMICAL PROPERTIES of pure substances Ability to act as reducing agent Reaction with other elements Decomposition into simpler substances Corrosion Reaction with acids Reaction with bases (alkalis) Reaction with oxygen (combustion) Ability to act as oxidizing agent

14. Comparison of properties

15. Physical and Chemical Properties can also be…… Intensive or Extensive

16. Intensive Property Does not depend on the size of the sample of matter. Boiling Point Melting Point Density Ductility

17. Extensive Property Does depend on the size of the sample of matter. Mass Volume Length