1. CHAPTER :MATTER & ENERGY Homework # 1
Physical VS Chemical Properties WS (online)
TOMORROW: TEST

2. 9/28 AIM # 1: How are physical changes differentiated from chemical changes?

3. What is a property?
Property is a characteristic of a substance that can be observed.

4. 1. Intensive and Extensive Properties

5. A. Intensive Property: Do not depend on the size of the sample
A. Intensive Property: Do not depend on the size of the sample. An intensive property doesn't change when you take away some of the sample
Color
Electrical conductivity
Boiling point and melting point
Ductility
Taste
Luster
Hardness
Density
Solubility
Malleability
Specific heat

6. B. Extensive Property Depend on the size of the sample.
An extensive property is a property that changes when the size of the sample changes
Mass
Volume
Length
Shape

7. 2. Physical Properties
Physical properties of a substance are those characteristics that can be observed without the production of new substances.

11. Copper
29Cu
Metal, conducts electricity, ductile (can be drawn into wires), malleable, and metallic luster.

12. Sulfur
16S
Nonmetals, do not conduct electricity, yellow color, brittle (breaks easily).

13. Oxygen O2
Nonmetal, gas, colorless, odorless, slightly denser than air, slightly soluble in water.

14. 3. Chemical Properties
Chemical properties of a substance are those characteristics that describe how the substance interact (or fails to interact) with other substances to produce new substances.

15.  Oxygen
Does not burn
Supports combustion

16. 4. Physical Change
Physical change is a change in form or state without a change in composition.

17. crushing a can 
melting ice cube 
boiling water
mixing sand and water 
breaking a glass 
dissolving sugar and water 
shredding paper 
chopping wood 
mixing red and green marbles 
sublimating (dry ice)

18. Sublimation: CO2(s)  CO2(g)

19. Sublimation: I2(s)  I2(g)

20. Physical Change

22. Grind Coffee

23. whipping egg whites (air is forced into the fluid, but no new substance is produced)

24. Boiling Water (water molecules are forced away from each other when the liquid changes to vapor, but the molecules are still H2O.)

25. Dissolving Sugar in Water (sugar molecules are dispersed within the water, but the individual sugar molecules are unchanged.)

26. Dicing Potatoes (cutting usually separates molecules without changing them.)

27. 5. Chemical Change
Chemical change is one in which a substance loses the properties by which we recognize it and produces a new substance.

28. How do you know when a chemical reaction is taking place?
8F Signs of a chemical reaction
How do you know when a chemical reaction is taking place?
gives out a gas
glows
color changes
Light
heats up
cools down
flashes
produces smoke
Precipitate
(solid)

32. Example
The burning of paper
Sugar + heat

33. Chemical change

34. Chemical Change

35. Iron Rusting

36. Color Change
You have just witnessed a spectacular chemical change if you have seen the leaves change color in the autumn.

37. Spring

38. Another sign of a chemical change is the release or gain of energy by an object.

39. Release of Heat and Light

40. Release of Energy (heat and light)

41. Odor Changes
It only takes one experience with a rotten egg to learn that they smell different that fresh eggs.  When eggs and food spoil, they undergo a chemical change.  The change in odor is a clue to the chemical change

42. Production of Gases Zn metal reacting with Hydrochloric Acid

43. Copper Metal Reacting with Nitric Acid
Production of Gases
Copper Metal Reacting with Nitric Acid

44. Production of Solids Pb(NO3)2 + KI <-> PbI2 + KNO3
Lead (II) Potassium Lead (II) Potassiun nitrate iodide iodide nitrate

45. Not Easily Reversed

46. Questions

47. 1. Water boils at 100 degrees Celcius.
physical property.

48. 2. Diamonds are capable of cutting glass.
physical property. .

49. 3. Sugar is capable of dissolving in water.
physical property.

50. 4. Vinegar will react with baking soda.
chemical property.

51. 5. Yeast acts on sugar to form carbon dioxide and ethanol.
chemical property.

52. 5. Wood is flammable.
chemical property.

53. 6. Aluminum has a low density.
physical property.

54. 7. Ammonia is a gas at room temperature.
physical property.

55. 8. Bromine has a red color.
This is a physical property.

56. 9. Dry ice, solid carbon dioxide, is sublimed at room temperature.
physical change.
Sublimation: solid to gas

57. 10. Salt is dissolved in water.
physical change.

58. 11. Iron rusts in a damp environment.
chemical change.

59. 12. Gasoline burns in the presence of oxygen.
chemical change.

60. 13. Hydrogen peroxide decomposes to water and oxygen.
chemical change.

61. End of the show!

62. iron rusting (iron oxide forms)
gasoline burning (water vapor and carbon dioxide form)
eggs cooking (fluid protein molecules uncoil and crosslink to form a network)
bread rising (yeast converts carbohydrates into carbon dioxide gas)
milk souring (sour-tasting lactic acid is produced)
Sun tanning (vitamin D and melanin is produced)