1. SN# 12 Physical and Chemical Changes

2. Physical Changes:. 1. Do not produce a new. substance
  Physical Changes: 1. Do not produce a new substance Melt Ice – still have water ALL states of matter changes are physical changes. Break a bottle – still have glass. * Some but not all can be reversed

3. If you break a bottle, you still have glass
If you break a bottle, you still have glass.  Painting your nails will not stop them from being fingernails.  Some common examples of physical changes are: melting, freezing, condensing, breaking, crushing, cutting, and bending.

4. Some, but not all physical changes can be reversed
Some, but not all physical changes can be reversed. You could refreeze the water into ice, but you cannot put your hair back together if you don’t like your haircut!

5. Special types of physical changes where any object changes state, such as when water freezes or evaporates, are sometimes called change of state operations.

6. CHEMICAL PROPERTIES
Chemical properties can ONLY be observed AS the substances are changing into different substances.

7. Chemical changes, involve the transfer of heat…
Chemical changes, involve the transfer of heat….endothermic or exothermic (bubbles, smoke, odor)

8. FLAMMABILITY: A material’s ability to BURN in the presence of OXYGEN

9. REACTIVITY: How readily (easily) a substance combines chemically with other substances.

10. Which has higher reactivity
Which has higher reactivity? A 14 karat gold ring or a cheap metal ring from the vending machine at the grocery store? What is your evidence?

11. When you burn a log in a fireplace, you are carrying out a chemical reaction that releases carbon.  When you light your Bunsen burner in lab, you are carrying out a chemical reaction that produces water and carbon dioxide. 

12. Common examples of chemical changes that you may be somewhat familiar with are; digestion, respiration, photosynthesis, burning, and decomposition. 

13. Physical or Chemical Change?
Painting Wood
PHYSICAL

14. Physical or Chemical Change?
Burning Paper
CHEMICAL

15. Physical or Chemical Change?
Digestion of food
CHEMICAL

16. Sugar dissolving in water PHYSICAL
Physical or Chemical Change?
Sugar dissolving in water
PHYSICAL

17. Iron turning red when heated PHYSICAL
Physical or Chemical Change?
Iron turning red when heated
PHYSICAL

18. Physical or Chemical Change?
Evaporation
PHYSICAL

19. A pond freezing in winter PHYSICAL
Physical or Chemical Change?
A pond freezing in winter
PHYSICAL

20. Physical or Chemical Change?
Melting ice
PHYSICAL

21. Physical or Chemical Change?
Cutting wire
PHYSICAL

22. Physical or Chemical Change?
Painting fingernails
PHYSICAL

23. Physical or Chemical Change?
Cutting fabric
PHYSICAL

24. Physical or Chemical Change?
Baking muffins
CHEMICAL

25. Physical or Chemical Change?
Shattering glass
PHYSICAL

26. Decomposition of old leaves CHEMICAL
Physical or Chemical Change?
Decomposition of old leaves
CHEMICAL

27. Physical or Chemical Change?
Wrinkling a shirt
PHYSICAL

28. Physical or Chemical Change?
An old nail rusting
CHEMICAL