A physical change alters a substance's physical properties but not its chemical identity, while a chemical change transforms a substance into different substances through breaking or forming of chemical bonds. Changes in color, mass, or release of gases indicate a chemical change has occurred, whereas changes in state or phase without a new substance forming signal a physical change. Students can identify if a change is physical or chemical based on observable evidence like changes in properties or formation of new substances.

1. 1/11/12 A/B Day
LEQ: What is the difference between a physical
and chemical change and how can we tell when
they happen?
1. What is the difference between a mixture and a
solution?
2. In a glass of chocolate milk, what is the solvent and
what is the solute?
3. What does solubility measure?
4. A scientist needs to use a material that will not get
very hot. Should the scientist use something with a
HIGH specific heat or a low specific heat?
5. EXPLAIN your answer to #4!

2. Let’s Review:
If each of these
materials is
exposed to the
same amount of
heat, which one
will be the
COOLEST?

3. HOT Q: If 5 grams of gold melts at
200° C, what temperature will cause
50 grams of gold to melt?

4. HOT Q: Which pure substance is
composed of more that one
element?
a.Carbon
b.Gold
c.Water
d.Sodium

5. Let’s Review!
NONMETALS
METALS
METALLOIDS

6. Help a Scientist pick the right element:
1. A metal
2. A nonmetal
3. A metalloid
4. Something malleable
5. Something ductile
6. Something that is magnetic
7. Something that will conduct heat
8. Something that will block heat
9. Something that is a semiconductor

7. FIND THAT ELEMENT!
1. GROUP 1, PERIOD 1 =
2. GROUP 6, PERIOD 7 =
3. GROUP 2, PERIOD 5 =
4. GROUP 9, PERIOD 4 =
5. GROUP 17, PERIOD 3 =
6. GROUP 11, PERIOD 4 =

8. EOG Question:
How can a scientist, using the periodic
table, find an element with properties similar to
another element?
a) by comparing density
b) by finding its periodic group
c) by comparing malleability
d) by comparing atomic weight

9. Chemical Mechanical
Weathering Weathering

10. CHEMICAL WEATHERING:
• Chemicals break down rock by
chemically changing the rock
• Usually indicated by color
change!
• Example: Acid Rain, rust

11. MECHANICAL WEATHERING:
• Physical changes to rock
(rocks break into smaller pieces)
• Example: ice, salt, wind, and
water break down rocks

12. Today’s LEQ: What is the difference
between a physical and chemical change
and how can we tell when they happen?
By the end of today, you should be able to…
1. Describe the difference between an physical
and chemical change.
2. Use observable evidence to decide if a
change is chemical or physical

13. FOCUS VOCABULARY:
87. Chemical Change
88. Physical Change

14. ACTIVATOR: Draw this in your notes

15. Record 3-5 observations you
have about the paper
How does the paper look
different?
What changed about the
paper?
What happened to the
paper?

16. Record 3-5 observations you
have about the paper
How does the paper look
different?
What changed about the
paper?
What happened to the
paper?

17. Demo: Tearing Paper, Burning Paper
How are the two
demos different?

18. Changing Substances
Physical Change: Chemical Change:
Ex. Ex.
Evidence: Evidence:
1. 1.
2. 2.
3. 3.
4. 4.

19. Draw this in your notes:
Changing Substances
Physical Change:
changes the physical
traits of a
substance, NOT the
identity of the
substance
TEARING PAPER!

20. Physical Change: Tearing paper
Paper

21. Draw this in your notes:
Changing Substances
Physical Change: Chemical Change:
changes the physical substance is changed
traits of a into a new substance
substance, NOT the (changes the identity
identity of the of something)
substance
Ex. Burning Paper!

22. Chemical Change: Burning paper
Paper
Burnt Paper is a
DIFFERENT
SUBSTANCE!

23. BrainPop: Changing Properties

24. Changing Substances
Physical Change: Chemical Change:
Ex. Ex.
Evidence: Evidence:
1. 1.
2. 2.
3. 3.
4. 4.

25. Instructions:
I give you: 8 different types of evidence
that happen during physical and chemical
changes
You: use your brain to decide which of
the things is evidence of physical change
and which of the things is evidence of
chemical change

26. Physical Chemical
-Changes color
-Melting, freezing, or boiling
EVIDENCE
-Burst of heat
-Change in mass or volume
-Smoke forms
-Change in shape
-Usually reversible
-Usually irreversible

27. Physical Change: Chemical Change:
Evidence: Evidence:
1. Melting, freezing, or 1. Changes color
boiling
2. Burst of heat
2. Change in mass or
volume
3. Smoke forms
3. Change in shape
4. Usually reversible 4. Usually irreversible

28. What evidence can we use to tell this
is a physical change?
Paper

29. What evidence can we use to tell
this is a chemical change?
Paper
Burnt Paper is a
DIFFERENT
SUBSTANCE!

30. Physical Change: Ice melting

31. Chemical Change: Making Water
+
Two One Water
Hydrogen Oxygen
Atoms Atom

32. Chemical
or
Physical?

33. Melting Ice

34. Burning Wood

35. Chopping Wood

36. Digesting an apple

37. Breaking Glass

38. Melting Iron

39. Bicycle rusting

40. Melting Ice Cream on a hot day

41. Cooking a steak

42. Mixing Peas and Carrots

43. Rotting Banana

44. Draw this in your notes:

45. SORT THESE!!
A nail
rusting

46. HOT Q: How do physical and
chemical changes relate to the
different ways that the surface of
the earth changes over time??

47. Key Points:
1. A _________ changes the physical
characteristics of a substance.
2. A __________ changes something into a new
substance.
3. Changing color is evidence of a ___________.
4. Changing phases or states of matter is
evidence of a __________________.

48. Summarizer:
1. What is the difference between a chemical
change and physical change?
2. Is melting copper an example of a physical or
chemical change?
3. How can you tell the answer to #2?
4. Is a rusting nail an example of a physical or
chemical change?
5. How can you tell the answer to #4?