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9/18/13
2.1 Properties of Matter > Describing Matter
2.1 Properties of Matter >
Describing Matter
Chapter 2
Matter and Change
Why do all samples of a substance
have the same intensive properties?
2.1 Properties of Matter
2.2 Mixtures
2.3 Elements and Compounds
2.4 Chemical Reactions
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2.1 Properties of Matter > Describing Matter
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2.1 Properties of Matter > Describing Matter
Extensive Properties
Matter is anything that has mass and
volume.
Properties used to describe matter can be
classified as
extensive or intensive.
•  Mass is the amount of matter an object
contains.
–  The mass of a
basketball is greater
than the mass of a golf
ball.
–  g, kg
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2.1 Properties of Matter > Describing Matter
2.1 Properties of Matter > Describing Matter
Extensive Properties
The volume of an object is a measure of
the space occupied by the object.
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Extensive Properties
Mass and volume are both extensive
properties.
•  The volume of a basketball is greater than the
volume of a golf ball.
•  An extensive property is a property that
depends on the amount of matter in a sample.
•  mL, L, cm3, cc
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9/18/13
2.1 Properties of Matter > Describing Matter
2.1 Properties of Matter > Describing Matter
Identifying a Substance
Intensive Properties
Matter that has a uniform and
definite composition is called a
substance.
Refractive index is an example of an
intensive property.
•  Aluminum and copper are
examples of substances, which
are also referred to as pure
substances.
•  An intensive property is a property that
depends on the type of matter in a sample,
not the amount.
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2.1 Properties of Matter > Describing Matter
2.1 Properties of Matter > Describing Matter
Examples of Physical Properties
Hardness
Solubility
Identifying a Substance
Every sample of a given substance
has identical intensive properties
because every sample has the same
composition.
Color
Magnetism
Conductivity
Malleability
•  A physical property is a quality or condition of a
substance that can be observed or measured
without changing the substance’s composition.
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2.1 Properties of Matter >
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2.1 Properties of Matter > Describing Matter
Interpret Data
Physical properties for some substances.
Physical Properties of Some Substances
Substance
State
Color
Melting point (°C)
Boiling point (°C)
Neon
Gas
Oxygen
Gas
Colorless
–249
–246
Colorless
–218
Chlorine
Gas
–183
Greenish-yellow
–101
–34
Ethanol
Liquid Colorless
Mercury
Liquid Silvery-white
Bromine
Liquid Reddish-brown
Water
Liquid Colorless
Sulfur
Solid
Yellow
Sodium chloride Solid
Gold
Solid
Copper
Solid
–117
78
–39
357
–7
59
0
100
115
445
White
801
1413
Yellow
1064
2856
Reddish-yellow
1084
2562
Using Physical properties to identify
substances.
•  A colorless substance that was found to boil at
100˚C and melt at 0˚C :
•  water
•  A colorless substance that boiled at 78˚C and
melted at –117˚C:
•  ethanol
•  The states of the substances are given at room temperature.
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9/18/13
2.1 Properties of Matter >
CHEMISTRY
2.1 Properties of Matter >
& YOU
What intensive properties of glass
make it a desirable material to use for
windows?
transparent
What properties can you determine without
knowing the amount of matter in the
sample?
Intensive properties:
hard
Conductivity, solubility, color,
magnetism
heat resistant
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2.1 Properties of Matter > States of Matter
2.1 Properties of Matter > States of Matter
Solids
States of Matter
Have a definite shape and volume.
Three states of matter are solid, liquid,
and gas.
•  The shape of a solid doesn’t depend on the
shape of its container.
•  Water exists in three different physical states.
•  Ice, steam, liquid water
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•  The particles in a solid
are packed tightly
together, often in an
orderly arrangement.
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2.1 Properties of Matter > States of Matter
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2.1 Properties of Matter > States of Matter
Solids
Liquids
Particles are in close contact,
but the arrangement is not
rigid or orderly.
•  Almost incompressible (difficult to squeeze
into a smaller volume)
•  Expand only slightly when heated
•  Flow
•  Takes the shape of the container
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2.1 Properties of Matter > States of Matter
2.1 Properties of Matter > States of Matter
Liquids
Gases
The volume of a liquid is fixed or constant.
•  Takes the shape of its container.
•  Indefinite shape
•  Can expand to fill any volume.
•  Fixed volume
–  Liquids are almost incompressible.
–  Tend to expand slightly when heated.
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2.1 Properties of Matter > States of Matter
2.1 Properties of Matter > States of Matter
Gases
Gases v. Vapor
•  The term gas is used for substances that
exist in the gaseous state at room
temperature. Examples?
Takes both the shape and
volume of its container.
•  particles are much farther apart
than in a liquid.
•  Vapor describes the gaseous state of a
substance that is generally a liquid or solid
at room temperature. Examples?
•  Therefore, easily compressed.
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2.1 Properties of Matter > Physical Changes
The melting point of
gallium metal is 30˚C.
How can physical changes be
classified?
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2.1 Properties of Matter > Physical Changes
Physical Changes
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The shape of the
sample changes during
melting, but the
composition does not
change.
•  During a physical change,
some properties of a
material change, but the
composition remains
constant
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2.1 Properties of Matter > Physical Changes
Physical changes can be classified as
reversible or irreversible.
•  Melting is reversible
•  Cutting hair, filing nails, and cracking an
egg are examples of irreversible physical
changes.
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