1. List 5 physical properties.
Warm-Up
List 5 physical properties.
List 5 physical changes.

2. 8th Grade Physical Science
Chemical Properties
8th Grade
Physical Science

3. What is the definition of physical property?

4. Physical Property
A characteristic of a substance that can be observed without changing the substance into another substance

5. What are some physical properties?

6. Physical Property
Examples: color, odor, shape, size, mass, volume, magnetism, ability to conduct electric current, strength, flexibility, texture, density, state, thermal conductivity, solubility, ductility, malleability, melting point, boiling point

7. What is a physical change?

8. Physical changes do not form new substances.

9. What are some physical changes?

10. Examples of Physical Changes
Boiling
Freezing
Dissolving
Breaking
Making a mixture - 2 or more types of matter (substances) mixed together
Can be separated physically
All phase changes are physical changes!

11. Henry takes a cup of water and places it in the freezer
Henry takes a cup of water and places it in the freezer. The liquid water changes to ice. Henry thinks this change is not a physical change, because the water changed into ice. Do you agree or disagree? Why?

12. What is a property?
Property: a characteristic of a substance that can be observed 12

13. Two kinds of properties:
Physical Properties
and
Chemical Properties

14. Physical Property
A characteristic of a substance that can be observed without changing the substance into another substance

15. Chemical Property
Describes matter based on its ability to change into new matter that has different properties

16. The ability of a substance to burn
Flammability
The ability of a substance to burn
Wood has the chemical property of flammability. When wood is burned, ash and smoke are created.

17. Reactivity
The ability of two or more substances to combine and form one or more new substances

18. Iron has the chemical property of reactivity with oxygen
Iron has the chemical property of reactivity with oxygen. When iron reacts with oxygen, it rusts.

19. Video

20. Substances can have chemical properties, even if you can’t observe them. A piece of wood is flammable even when it’s not burning.

21. Chemical Change
Happens when one or more substances are changed into new substances that have new and different properties.

22. Chemical properties describe which chemical changes will occur and which will not occur.

23. Chemical change is the process by which substances actually change into new substances.

24. With paper, I know that it has the chemical property of flammability without even lighting it on fire.

25. It’s not until I light the paper on fire that the paper has a chemical change.

26. With baking soda, I know that it has the chemical property of reactivity with vinegar.

27. It’s not until I mix baking soda and vinegar that the two have a chemical change.

28. In a chemical change, the new product(s) are different from the substances that were initially combined together.

29. +
Carbon dioxide + Water

30. Burning wood is a chemical change. The wood is changed to ash and smoke.

31. Signs of a Chemical Change
Change in Color Production or Change in Odor Change in Temperature Production of Precipitate (solid) Production of a Gas (bubbling)

32. Many physical changes are easily reversed.
Most chemical changes are not easily reversed.

33. When determining if the change is physical or chemical, you should ask yourself if the composition changes.

34. The composition of an object is the type of matter that makes up the object and the way that the matter is arranged in the object.

35. Physical changes DO NOT change the composition of a substance.

36. Chemical changes alter the composition of the substance.

37. Physical Change or
Chemical Change?

38. Physical
The composition stays the same.
Substance is not changed, just size or shape
Change can be undone.
Color changes (careful!)
Changing State
Dissolving
Bending, Crushing, Mixing, Cutting, etc.
Chemical
The composition changes.
Change CANNOT be undone.
Color changes (careful!)
Production of gas (bubbles)
Production/Change in odor
Change in temperature
Production of precipitate

39. Cracking Eggs

40. Physical Change
Cracking an egg separates the shell from the insides. The substances do not change.

41. Slicing Bread

42. When the bread is sliced, the bread just changes size and shape.
Physical Change
When the bread is sliced, the bread just changes size and shape.

43. Lighting a Match

44. The phosphorus and wood are changed into new substances.
Chemical Change
The phosphorus and wood are changed into new substances.

45. Rusty Nails

46. Chemical Change Oxygen in the air reacts with the metal of the nail.
This produces a new substance called rust.

47. Ice Melting

48. Physical Change
The ice just changes from solid to liquid. The water does not change into a new substance.

49. Glass Breaking

50. Physical Change
The glass does not change into a new substance.

51. Boiling Water

52. Physical Change
When water boils, water changes from a liquid to a gas.
The identity of the water does not change.

53. Mixing Lemonade Powder into Water

54. Evaporating the water separates the ingredients.
Physical Change
After mixing the lemonade powder and water, lemonade powder and water are still present.
Evaporating the water separates the ingredients.

55. Baking a Cake

56. Chemical Change
The flour, eggs, sugar, baking powder, and other ingredients change into a new substance.

57. Mowing the Lawn

58. Cutting the grass does not change the identity of the grass.
Physical Change
Cutting the grass does not change the identity of the grass.

59. Fireworks Exploding

60. Chemical Change
Fireworks are composed of different metals, such as copper.
After ignited, the fireworks produce light, heat, and sound.

61. Melting Butter for Popcorn

62. Physical Change
Heating causes the butter to change from a solid to a liquid.
The identity of the butter does not change.

63. Hammering Wood Together to Build a Birdhouse

64. Physical Change
Hammering the wood together causes the wood to change shape.
The identity of the wood does not change.

65. Spoiling Food

66. Chemical Change Spoiling food changes color and has a foul odor.
Bacteria, mold, enzyme action, and oxidation cause spoilage.

67. Separating a Mixture of Rocks and Sand

68. Physical Change
Separating the rocks from the sand can be done by physical means.
The identities of the rocks and sand do not change.

69. Exit Slip Define and give an example of a physical property.
Define and give an example of a physical change.
Define and give an example of a chemical property.
Define and give an example of a chemical change.