1. Physical & Chemical
Changes
•Is melted butter still butter?
•Is soured milk still milk?
•Are the ashes from a fire made of the same
“stuff” as wood?
7th Grade
Brandy Butcher

2. What is a physical change?
 Change that affects one or more
physical properties of a substance
 A new substance is not formed
 The substance keeps its identity
(name)

3. Examples of Physical Change
 Any state change
◦ Melting
◦ Freezing
◦ Evaporating
 Dissolving
 Cutting
 Bending

4. Examples of Physical Changes
in Nature
 Water Cycle
 Erosion

5. Can you think of any examples?

6. What is a chemical change?
 One or more substances are changed
into a new substance
 New and different properties
 New identity (name)

7. Examples of a Chemical Change
 Cooking
 Burning
 Rusting

8. Examples of Chemical Changes
in Nature
 Carbon Cycle
 Nitrogen Cycle
 Chemical Weathering

9. Can you think of any examples?

10. What are the signs a chemical
change is happening?
 Change in color
 Change in odor
 Production of heat
 Production of fizzing, foam, bubbles
 Production of sound
 Production of light

11. What signs do this changes
demonstrate?
Change in odor and
color
Change in odor and
color
Change in color

12. Physical or Chemical Change?
 Frying an egg?
 Physical or Chemical

13. Incorrect. Try again!

14. Correct!
Try the next one!

15. Physical or Chemical Change?
 Souring Milk?
 Physical or Chemical

16. Incorrect. Try again!

17. Correct!
Try the next one!

18. Physical or Chemical Change?
 Shredding paper?
 Physical or Chemical

19. Incorrect. Try again!

20. Correct!

21. Credits
 All pictures used were free and
retrieved from www.morguefile.com.