chemical and physical properties/changes

1. Physical and
Chemical
Properties of
Matter

2. What is a physical property of
matter?
• A property that can be observed or
measured without changing the identity
of that matter
• Ex: Color, odor, shape, size, etc.

3. Thermal Conductivity
Definition:
 The ability to
transfer thermal
energy (heat) to
something else
Example:
 Coffee in a
special cup to
prevent heat
transfer to our
hands

4. State
Definition:
 The form in
which matter
exists: solid,
liquid, gas, or
plasma
Example:
 Ice = Solid
 Water = Liquid
 Helium = Gas
 Lightning = Plasma

5. Malleability
Definition:
The ability to
be pounded
into thin
sheets
Example:
Aluminum can
be pounded
flat to make
aluminum foil

6. Ductility
Definition:
The ability to
be drawn into
thin wires
Example:
Copper is
used to make
wires

7. Example:
 Alka-seltzer
dissolves in
water or sugar
dissolves in
coffee
Solubility
Definition:
 The ability for
one substance
to dissolve into
another
substance

8. Density
Definition:
 Mass per unit
volume
Example:
 Lead is used for
fishing weights
because it is
more dense
than water

9. More information about density...
 Density = The amount of matter in
a given space or volume
 Density = m Mass
v Volume

10. More information about density...
 Most substances have a unique
density:
Water = 1.00 g/mL
Gold = 19.32 g/mL
(See page 13 in your book for a bigger list)
 Density < 1 - The object will float in water
 Density > 1 – The object will sink in water

11. The Magic Triangle
 Answers are expressed in g/cm3
or g/mL

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

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

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

15. Physical and
Chemical Changes

16. Physical changes are those
changes that do not result in the
production of a new substance.
If you melt a block of ice, you
still have H2
O at the end of the
change.

17. Physical Changes
• Physical changes do not result in the formation of a
new substance and are reversible.
• The following are examples of physical changes:
• Melting and freezing
• Boiling and condensation
• Forming a separable mixture

18. 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.

19. 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!

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

21. Chemical changes, or chemical
reactions, are changes that result
in the production of another
substance.

22. Chemical Changes
 Chemical changes result in the formation of
a new substance and tend to be
irreversible.
 The following observations often suggest
that a chemical change has taken place:
 Colour change
 Evolution (release) of gas
 Temperature change
 Solution turns cloudy
 Change of pH

23. Signs for chemical changes
 Color change
 Gas formation (fizzing/bubbles)
 Change in light and temperature
 Precipitate (solid formation)

24. 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
CHANGE that produces water
and carbon dioxide.

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

26. Physical or Chemical Change?
Painting Wood
PHYSICAL

27. Physical or Chemical Change?
•Burning Paper
•CHEMICAL

28. Physical or Chemical Change?
•Digestion of food
•CHEMICAL

29. Physical or Chemical Change?
•Sugar dissolving in
water
•PHYSICAL

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

31. Physical or Chemical Change?
•Evaporation
•PHYSICAL

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

33. Physical or Chemical Change?
•Melting ice
•PHYSICAL

34. Physical or Chemical Change?
•Cutting wire
•PHYSICAL

35. Physical or Chemical Change?
•Painting fingernails
•PHYSICAL

36. Physical or Chemical Change?
•Cutting fabric
•PHYSICAL

37. Physical or Chemical Change?
•Baking muffins
•CHEMICAL

38. Physical or Chemical Change?
•Shattering glass
•PHYSICAL

39. Physical or Chemical Change?
•Decomposition of old
leaves
•CHEMICAL

40. Physical or Chemical Change?
•Wrinkling a shirt
•PHYSICAL

41. Physical or Chemical Change?
•An old nail rusting
•CHEMICAL