Physical and Chemical Properties and Changes

1. Physical and Chemical Properties and Changes

2. Catalyst (10 min) Write down the answers to the following questions on a piece of notebook paper. This will be collected at the end of class for part of your daily grade • How do you decide whether a sample of matter is a solid, liquid or gas (describe in terms of shape, volume, compressibility and particles) • How is a solid similar to a liquid? • How is a liquid similar to a gas? • Assemble flip book (see sample at the front of the room)

3. Objectives • SWBAT distinguish between the physical properties and chemical properties of matter • SWBAT describe physical and chemical changes and classify changes of matter as physical or chemical

4. Agenda • I do: lecture and frayer notes • We do: distinguish between physical and chemical properties and changes on white boards • You do: work with partners and classify the changes and properties of different substances

5. Vocabulary Word Definition         Characteristic(s)/Fact(s) Example(s) Illustration

6. Physical Property Characteristics: • Describes the substance itself • Can be determined by viewing, touching or measuring the substance Definition: • A characteristic that can be observed or measured without changing the sample’s composition

7. Physical Property Examples: • Melting/boiling point • Density • Electrical and heat conductivity • Color • Size or mass • Luster (shine) • Odor • Hardness or Brittleness • Temperature

8. Intensive vs. extensive physical property Extensive properties: • Dependent upon the amount of substance present Intensive properties: • Independent of the amount of substance present

9. chemical Property Characteristics: • Cannot be determined just by viewing or touching the substance • Internal structure of the substance must be changed to observe the property Definition: • Ability of a substance to combine with or change into one or more other substances

10. Chemical Property Examples: • Chemical stability • Flammability • How easily it reacts with other substances

11. Physical Change Characteristics: • Can involve a change of state • Does not change what the substance is Definition: • Changes which alter a substance’s physical appearance but the composition remains unchanged

12. Physical Change Examples: • Hair cut • Boiling, freezing or melting a substance • Sugar cube dissolving

13. chemical Change Characteristics: • Involves a chemical reaction • Changes color, smell, energy, formation of gas, precipitate and/or light Definition: • Change in which a substance is transformed to one or more new substances with altered compositions

14. Observable factors of a chemical Change

15. Chemical Change Examples: • Fireworks • Burning coal • Iron rusting • Scientist breaking water into oxygen and hydrogen gas

16. Physical vs. chemical change

17. Mercury oxide -> oxygen + Mercury

18. WE Do: Grab a white board for your group

19. Identify whether the following are physical or chemical changes and use your notes to explain why

20. Lighting a match

21. Crushing aluminum cans

22. Digesting food

23. Two cans of paint mixed together

24. Using hot glue

25. Mixing baking soda and vinegar

26. Water freezing and forming ice

27. Identify whether the following are physical or chemical properties and use your notes to explain why

28. Silver tarnishes when it comes in contact with hydrogen sulfide in the air

29. A banana is yellow

30. A sheet of copper can be pounded into a bowl

31. Gasoline is flammable

32. An apple will turn brown if left in oxygen

33. Acid in tomato sauce can corrode aluminum foil

34. Barium melts at 725 C

35. A sheet of copper can be pounded into a bowl

36. You do: identify chemical and physical properties and changes • Read the packet and identify the physical and chemical properties and changes of the substance • Make a table to record your answers

37. Homework # 2 Classify the following as chemical change (cc), chemical property (cp), physical change (pc), or physical property (pp). Explain WHY for each answer. • Heat conductivity • Combustible • Silver tarnishing • Water freezing • Melting ice • Wood burning • Iron rusting • Density of a coin • Length of a metal object • Brittleness • Color • Cutting grass • Exploding dynamite • Baking bread

38. HOT Question 1 Tyreke made the following statement when speaking to his lab partners: "Breaking a rock into several pieces is an example of a chemical change. When I started, I had one substance (a rock). At the end, I had several different substances (the different sized pebbles).“ Assess the validity of his claim and justify your reasoning.

39. HOT Question 2 Water (H2O) is made of Hydrogen (a gas) and Oxygen (also a gas). Water is a liquid at room temperature. Based on this, it seems like hydrogen and oxygen combining to form water is a physical change (gases turning into solids). Do you agree with this assessment? Why or why not?

40. HOT Question 3 Chlorine is a yellowish gas at room temperature that reacts easily with sodium (a shiny silver metal) to form sodium chloride (NaCl-- table salt). Ingesting either chlorine or sodium alone will kill you. Ingesting table salt alone will just make you thirsty. Using your knowledge of physical and chemical changes, discuss whether you believe the formation of NaCl is more of a physical change or a chemical change.