Physical and Chemical Changes

1
Physical and Chemical Changes

• Chem 8

2
Physical Change

• change in the size, shape, or state of matter

Key Words Boiling Freezing Cutting Dissolving mel
ting
3
Chemical Change

• A change of one substance in a material to a
  different substance
• EX foaming of antacid tablet
• What in the picture is chemically changing?

4
Chemical Reactions

• When a chemical reaction occurs, there is always
  a change in the properties and energy content of
  the substances involved. There is a change in
  both the physical and chemical properties as
  substances are changed into new substances. Most
  of the time, at least one of the following will
  be obvious when a chemical reaction takes place

5
6 indications of a chemical change

• 1. Color change
• 2. precipitate - cloudy
• 3. formation of light
• 4. heat given off
• 5. gas given off bubbles/ fizzes
• 6. new substance with new properties

6
KEY WORDS for CHEMICAL CHANGES

• Reacts
• Combusts
• Neutralize
• Rusts
• Corrodes
• Decays
• Cooking or baking
• Digesting

7
LAW OF CONSERVATION OF MATTER ENERGY
States that Mass cannot be created or destroyed
only conserved IT ONLY CHANGES FORMS 
8
Law of Conservation of Mass