1. Physical
Changes

2. Did you know?
Matter is changing around you all the time. Some changes are physical and some are chemical

3. Do you remember what Physical Properties are???
Color
Shape
Mass
Volume
State of Matter
Length
Magnetism
Texture
Density

4. After a PHYSICAL CHANGE, the appearance of the substance may be different but it is still the same substance
A physical change does not produce a new substance – molecules are the same

5. Physical property: States of Matter
What does this mean?
Only one substance goes into the reaction and one substance comes out.
Water  Water
Physical property: States of Matter

6. Cutting a Steak 
Steak
Steak 

7. What physical property changed?
State of matter
Size, shape, mass, volume
Is it still the same substance?
This is a physical change because before and after being cut the substance is still steak even if the size, shape, and other physical properties changed. It changed from one bigger piece into smaller pieces but no new substance was produced.

8. Bending Metal Wires 
Metal wires
Metal wires 

9. What physical property changed?
Shape
Why is this a physical change?
Bending metal wires is a physical change because a physical change means that no new substance is produced. Although the wires look different they are still the same substance, metal. It just changed shape from flat to bent.

10. Ice Cream Melting 
Ice cream
Ice cream 

11. What physical property changed?
State of matter
Solid  Liquid
Is it still the same substance?
This is a physical change because in a physical change the substance stays the same even if it looks different. The only thing that changed about the ice cream is its state of matter (solid to a liquid) but it is still ice cream after it melts.

12. Exit Ticket A pencil being sharpened
Evidence: What physical property changed?
Reasoning: Why is this a physical change?
2) Water condensing on your winshield

13. Breaking glass Glass  Glass What physical property changed?
Shape, volume, texture, mass, etc.
Is it still the same substance?
Yes! Still glass
Why? It just changed from one piece to a bunch of smaller pieces

14. Chemical Properties
and Changes

15. Chemical Properties

16. Chemical Properties
Describes matter based on its ability to change into a new substance with different properties

17. Chemical Properties
These properties can only be observed during a chemical reaction
A chemical change has to take place in order to observe them!!!

18. Chemical Properties Flammability Does it burn?
How likely is it to burn?

19. Flammability Can you think of any substances that are very flammable?
Gasoline
Paper
Wood

20. Flammability Can you think of any substances that are not flammable?
Water

21. Examples of Chemical Properties
What is a reaction? What are some examples of types of reactions?
Reactivity

22. Examples of Reactivity
Reacts with oxygen
What happens when this substance reacts with oxygen?

23. Reacting with oxygen Rust!
When exposed to oxygen for long periods of time, metal will react with the oxygen to form RUST

24. Examples of Reactivity
Reacts with water
What happens to the substance when it interacts with water?

25. Examples of Reactivity
Alka Seltzer and water

26. Example #1 You light a candle. Flammability or Reactivity?
How do you know?
It describes the substance’s ability to burn. A candle can burn easily, therefore it is flammable.

27. Example #2 Vinegar will react with baking soda.
Flammability or Reactivity?
Reactivity
How do you know?
Vinegar is reacting with baking soda and carbon dioxide is produced. This describes the interaction between two substances.

28. Example #3 Yeast acts on sugar to form carbon dioxide and ethanol
Flammability or Reactivity?
Reactivity
How do you know?
Yeast is reacting with sugar and forms two new substances, carbon dioxide and ethanol.

30. Example When charcoal burns in a BBQ grill
Reaction between Carbon and Oxygen
Provides heat that cooks the dinner and gives off CO2

31. Chemical Changes

32. A new substance is formed!
After a CHEMICAL CHANGE, a NEW substance is produced with NEW properties. These properties are different from the original substance!
A new substance is formed!

33. Signs that a Chemical Change took place
Production of a gas
Often appearing as bubbles
If it involves FIRE it involves gas (carbon dioxide in the smoke)

34. Signs that a Chemical Change took place
Change in temperature
Such as the production or loss of heat

35. Endothermic reaction
A chemical reaction resulting in the loss of heat

36. Endothermic reaction
Example: Ammonium nitrate and water in ice packs

37. Exothermic reaction
Exothermic reaction: A chemical reaction resulting in the production of heat

38. Exothermic reaction Example
Example: Hand warmers
Iron reacts with oxygen to produce heat
Iron & Oxygen  heat

39. Signs that a Chemical Change took place
New color
A chemical reaction results in a color change
Metal and oxygen react to form RUST
Color changes from silver to brownish red

40. Signs that a Chemical Change took place
Formation of a precipitate
An insoluble solid that forms out of a water solution
It forms because the solid does not dissolve in water

41. Example #1: Burning wood

42. Example #1: Burning wood
What chemical property is present?
Flamability
What is the evidence of a chemical change?
Production of a gas (SMOKE)
Change in temperature
Is it still the same substance?
No! Ashes

43. Example #3: Digestion of Pizza

44. Example #3: Digestion of Pizza
What chemical property is present?
Reactivity
What is the evidence of a chemical change?
New substances with new properties
Food is broken down by acid
Is it still the same substance?
No!
Food is broken down into other substances (basic molecule types)

45. Example #2: Rusting of Metal

46. Example #2: Rusting of Metal
What chemical property is present?
Reactivity
What is the evidence of a chemical change?
Change in color
Silver to reddish brown
Is it still the same substance?
No! Different properties

47. Physical or Chemical???
Use the A-F cards to separate the Physical Changes from the Chemical Changes!
D. Rubbing alcohol evaporates from your hand
E. Hydrogen peroxide bubbles when you put it on a cut on your leg
F. Your friend melts some butter for her popcorn
A. You cut a sheet of aluminum foil in half
B. You leave the milk on the counter all night and discover it has soured in the morning
C. Your Mom lights a candle in a dark room