1. Evidence of Chemical Reactions

2. Alter the size &/or shape
Physical Changes
Alter the size &/or shape
Cut, grind, dissolve

3. Physical Changes
Phase Changes

4. Easily changed back to original form
Physical Changes
Easily changed back to original form

5. Chemical Changes New stuff is made
Cannot change new stuff back into original form easily
Chemical composition of new substance is different from original

6. Hint- Can you turn cooked chicken back into raw chicken?
Physical or Chemical?
Hint- Can you turn cooked chicken back into raw chicken?

7. 5 Evidences of Chemical Change
Smell Change
Color Change
Energy change (hot, cold, light, sound, electricity, etc.)
Bubbles, fizzing, gas produced
Precipitate (2 clears make a cloudy)

8. Baked cupcakes smell differently than batter
#1 Smell Change
Baked cupcakes smell differently than batter

9. #2 Unexpected Color Change
Colorless methane burns blue

10. As candle was burns, it gives off heat and light
#3 Energy Change
As candle was burns, it gives off heat and light

11. Evidence of a Chemical Reaction
A gas evolves

12. Alka Seltzer in water makes carbon dioxide gas
#4 Bubbles or Fizzing
Alka Seltzer in water makes carbon dioxide gas

13. Evidence of a Chemical Reaction
Precipitation – a solid is created.

14. Evidence of a Chemical Reaction
Formation of water-

15. Evidence of a Chemical Reaction
Changes in energy to the system
It gets colder
It gets hotter

16. SUMMARIZE
Every reaction we did shows evidence of chemical change- what are 5?
Please- Precipitate (2 clears make cloudy)
Excuse- Energy change (heat, light, sound, electricity)
Coughs- Color change (unexpected)
Sneezes- Smell Change
Burps- Bubbles or fizzing (gas produced)