2. Physical vs. Chemical Changes

3. Warm-up 2 May 2015 From the “Cooking with Chemistry” activity, describe how did you use phase change to complete the final task of separating the salt from the solution? http://whatscookingamerica.net/Foto4/BoilingWater.bmp

4. Standard 2 May 2015 5.a. I know reactant atoms and molecules interact to form products with different chemical properties.

5. Physical Property:Chemical Property: Example: Physical Change: Chemical Change: Example: Example: Signs of a physical change: Signs of a chemical change:

6. What’s the Difference? Matter can change Examples: Freeze, cut, burn, etc. 2 types of changes 1. Physical changes 2. Chemical changes

7. Physical Property Characteristic of matter that does not change the substance (using senses)

8. Physical Changes Matter changes form WITHOUT becoming something new – You start and end with same thing (see below) Examples: cutting, freezing, melting, etc.

9. Molecules in Physical Changes

10. Chemical Property Describes matter on its ability to change into new matter – Flammability: ability of substance to burn – Reactivity: ability of substance to change into new substance

11. Chemical Changes Matter changes, becomes NEW substance – Start and end with different things Usually irreversible (can’t change back) Examples: burning, rusting, milk going sour

13. Signs of Change Physical – Size – Shape – Texture Chemical – Temperature – Color – Bubbles/fizzing – Smoke – Smell

14. Reactants: Products: Chemical Change = _________________ In chemical changes, atoms and molecules re-arrange to form new substances.

15. Molecules in Chemical Changes The atoms arrange to make a new substance

16. Chemical Change = Reaction Products: the resulting solutions in a reaction Reactants: starting solutions in a reaction ______________ Liquid ____________ Powder/dry I noticed the …… Mixing Things Up: Chemical Change Demos Observations of Reactants: Observations during the demonstration:

17. Chemical Change = Reaction Products: the resulting solutions in a reaction Reactants: starting solutions in a reaction QuestionAnswer A chemical reaction between two materials occurs if the properties of the products (what you make) are different from the reactants (what you mix). Was what you observed today a chemical reaction? Explain!

18. Chemical Change = Reaction Products: the resulting solutions in a reaction Reactants: starting solutions in a reaction Chemical reactions have formulas just like molecules and compounds. As a class, we will write the chemical equation below and label the reactants and the products. Reactants: Products: Reactants: Products: Chemical Formula In words

19. Chemical Reaction Demo NaHCO3 NaOOCCH3 + HOOCCH3 + H2O + CO2 Sodium Acetate, water, and carbon dioxide Sodium Bicarbonate and Acetic Acid

20. Chemical Change = Reaction Products: the resulting solutions in a reaction Reactants: starting solutions in a reaction Summary: How can you tell if a chemical reaction happened? What are evidences to support that chemical reaction happened? After a chemical reaction will it be possible to bring back the reactants to their original form (state and properties)? How is chemical reaction related to chemical change?

21. Signs of Chemical Change Fizzing/gas formation Flash/lightsmoke Change in temperature Smell/odor Change in color

22. Warm-up 2 May 2015 Give an example of a physical change and a chemical change, and then describe how they are different from the other. Explain your answer in 2-3 sentences.

23. Warm-up 2 May 2015 Why is cooking/baking similar to science? Explain your answer.

24. Physical Change vs. Chemical Change ObjectiveTo correctly identify and differentiate physical change from chemical change. QuestionAre changes (physical and chemical) only present inside the laboratory? How are physical change different from chemical change? HypothesisIf physical change does not produce a new product, then I can ….

25. Chemical Change = Reaction Products: the resulting solutions in a reaction Reactants: starting solutions in a reaction Steps Physical or Chemical Observations:

26. Chemical Change = Reaction Products: the resulting solutions in a reaction Reactants: starting solutions in a reaction StepsPhysical or Chemical Breaking graham crackers Observations:

27. Chemical Change = Reaction Products: the resulting solutions in a reaction Reactants: starting solutions in a reaction StepsPhysical or Chemical Breaking graham crackers Breaking chocolate bar Observations:

28. Chemical Change = Reaction Products: the resulting solutions in a reaction Reactants: starting solutions in a reaction StepsPhysical or Chemical Breaking graham crackers Breaking chocolate bar Cooking Marshmallow Observations:

29. Chemical Change = Reaction Products: the resulting solutions in a reaction Reactants: starting solutions in a reaction StepsPhysical or Chemical Breaking graham crackers Breaking chocolate bar Cooking Marshmallow Stacking cracker, chocolate, and marshmallow Observations:

30. Chemical Change = Reaction Products: the resulting solutions in a reaction Reactants: starting solutions in a reaction StepsPhysical or Chemical Breaking graham crackers Breaking chocolate bar Cooking Marshmallow Stacking cracker, chocolate, and marshmallow Chocolate melting Observations:

31. Chemical Change = Reaction Products: the resulting solutions in a reaction Reactants: starting solutions in a reaction StepsPhysical or Chemical Breaking graham crackers Breaking chocolate bar Cooking Marshmallow Stacking cracker, chocolate, and marshmallow Chocolate melting Eating smore! Observations:

32. Chemical Change = Reaction Products: the resulting solutions in a reaction Reactants: starting solutions in a reaction Discussion/Summary: How will you know if an object underwent a chemical or physical change? Can changes happen outside of the science classroom or laboratory?

33. Physical Change v. Chemical Change Make a Venn Diagram to compare the 2 types of changes

34. Is it a chemical or physical change? Sugar dissolving in tea Chemical Change Physical Change

35. OOPS! Did it change size, color, shape (Physical Change)? or Did it become different matter (Chemical Change)?

36. Correct!

37. Is it a chemical or physical change? Logs burning Chemical Change Physical Change

38. OOPS! Did it change size, color, shape (Physical Change)? or Did it become different matter (Chemical Change)?

39. Correct!

40. Is it a chemical or physical change? Breaking water up by separating it into hydrogen and oxygen Chemical Change Physical Change

41. OOPS! Did it change size, color, shape (Physical Change)? or Did it become different matter (Chemical Change)?

42. Correct!

43. Is it a chemical or physical change? Cutting paper Chemical Change Physical Change

44. OOPS! Did it change size, color, shape (Physical Change)? or Did it become different matter (Chemical Change)?

45. Correct!

46. Is it a chemical or physical change? Crushing an aspirin Chemical Change Physical Change

47. OOPS! Did it change size, color, shape (Physical Change)? or Did it become different matter (Chemical Change)?

48. Correct!

49. Is it a chemical or physical change? Metal rusting Chemical Change Physical Change

50. OOPS! Did it change size, color, shape (Physical Change)? or Did it become different matter (Chemical Change)?

51. Correct!

52. Is it a chemical or physical change? An egg rotting Chemical Change Physical Change

53. OOPS! Did it change size, color, shape (Physical Change)? or Did it become different matter (Chemical Change)?

54. Correct!

55. Is it a chemical or physical change? An egg breaking Chemical Change Physical Change

56. OOPS! Did it change size, color, shape (Physical Change)? or Did it become different matter (Chemical Change)?

57. Correct!

58. Standards 8.5.c. I know chemical reactions usually liberate or absorbs heat. Endothermic and Exothermic Reactions

59. When chemical reactions occur, the connections between atoms must be broken and rearranged. In order to do this, ________________ is involved in all chemical reactions. Heat

60. There are 2 Types of Reactions Involving Heat Endothermic Exothermic Within- Heating Endo = Enter Therm/ic = Heat Outside- Heating Exo = Exit Therm/ic = Heat

61. There are 2 Types of Reactions Involving Heat (cont.) EndothermicExothermic Reactions in which the system absorbs heat from the surrounding. Reactions in which the system releases heat to the surrounding.

62. There are 2 Types of Reactions Involving Heat (cont.) EndothermicExothermic It feels: ColdHot

63. There are 2 Types of Reactions Involving Heat (cont.) EndothermicExothermic Examples: Cooking an egg Baking a bread Candle flame Rusting Iron

64. Frayer Model Exothermic Reaction

65. Frayer Model Endothermic Reaction

66. Chemical Change = Reaction Products: the resulting solutions in a reaction Reactants: starting solutions in a reaction Weekly Reflection/Exit Slip Name 4 items you learned in this week’s lesson. If Mr. Rivera will teach the lesson again, will you want it done differently? If you want it done differently, why and how would you want it? If you want it done the same, why?