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Chapter 2
Properties of Matter
Pages 37-65
Section 1
Classifying Matter
Pages 38-44
Matter

Matter can be broken down into two categories:
Pure substances and Mixtures

Pure substances can be either elements or
compounds

Mixtures can be either homogeneous or
heterogeneous
Matter
The classification depends on particle size and type
Pure Substances

Matter that always has the same composition is
classified as a pure substance.

Every sample of a given substance has the same
properties because a substance has a fixed,
uniform composition.
Elements

An element is a substance that cannot be broken
down into simpler substances.

An atom is the smallest particles of an element.

An element has a fixed composition because it
contains only one type of atom.
Elements
Symbols:
I
Cu
Hg
C
Compounds

A compound is a substance that is made from
two or more simpler substances and can be
broken down into those simpler substances.

A compound always contains two or more
elements joined in a fixed proportion.
Mixtures

The properties of Mixtures are less constant
than the properties of substances.

The properties of a mixture can vary because
the composition of a mixture is not fixed.

There are two main types: heterogeneous and
homogenous
Mixtures
Heterogeneous

The parts of the mixture
are noticeably different
from one another.
Homogeneous

The parts are so evenly
distributed that it is
difficult to distinguish
one substance in the
mixture from another.
Solutions, Suspensions and Colloids

Based on the size of its largest particles, a
mixture can be classified as a solution, a
suspension, or a colloid.
Solutions

Substances dissolve and form a homogeneous
mixture
Suspensions

A heterogeneous mixture that separates into
layers over time
Colloids

Contains some particles that are intermediate in
size between the small particles in a solution and
the larger particles in a suspension. They also
scatter light
Section 2
Physical Properties
Pages 45-51
Physical Properties

A physical property is any characteristic of a
material that can be observed or measured
without changing the composition of the
substances in the material.

Viscosity, conductivity, malleability, hardness,
melting point, boiling point, and density are
examples of physical properties.
Viscosity

The tendency of a liquid to keep from flowing –
its resistance to flowing – is called its viscosity.

The greater the viscosity, the slower the liquid
moves.
How might
you change
a liquid’s
viscosity?
Conductivity

A material’s ability to allow heat to flow is called
conductivity.

Materials that conduct heat well usually conduct
electricity well, too.
Electricians often use a tool
called a multimeter to see if
a wire is “hot” or has power
running to it.
Malleability

Malleability is the ability of a solid to be
hammered without shattering.

The opposite of malleable is brittle.
This doubloon was made by
tapping gold with a small
hammer and an item called
a punch.
Hardness

Hardness is the ability to scratch another item.
Moh’s Hardness Scale is used to check the
hardness of various items against known
constants.
Melting Point and Boiling Point

The temperature at which a substance changes
from a solid to a liquid is called the melting
point. The temperature at which the substance
boils is its boiling point.
As the Earth’s
temperature
rises the polar
ice caps are
melting.
Density

Density, you recall, is a ratio of an objects mass
per unit of volume.
The various substances in
this density column can
be poured on top of one
another to create distinct
layers because their
densities are different.
The lower densities are on
top / floating.
Using Physical Properties

Physical properties can be used to identify
materials.
Water boils at a known temperature.

They can also be used to choose proper
materials for different jobs.
You probably don’t want to use rubber for
the wires in your house, it doesn’t conduct
very well.
Separating Mixtures

Filtration is a process that separates materials
based on the size of their particles.
Separating Mixtures

Distillation is a process that separates the
substances in a solution based on their boiling
points.
A substance can be boiled
out of a mixture in a process
known as distillation.
Recognizing Physical Changes

A physical change occurs when some of the
properties of a material change, but the
substances in the material remain the same.
Section 3
Chemical Properties
Pages 54-61
Observing Chemical Properties

A chemical property is any ability to produce a
change in the composition of matter.

Chemical properties can be observed only when
the substances in a sample of matter are
changing into different substances.
Flammability

Flammability is a material’s ability to burn in the
presence of oxygen.
Reactivity

The property that describes how readily a
substance combines chemically with other
substances is reactivity.
Recognizing Chemical Changes

A chemical change occurs when a substance
reacts and forms one or more new substances.

Three common types of evidence for a chemical
change are a change in color, the production of
a gas, and the formation of a precipitate.
Change in Color
Production of a Gas
Formation of a Precipitate

Any solid that forms from a liquid mixture is
called a precipitate.
Is a Change Chemical or Physical?

When matter undergoes a chemical change, the
composition of the matter changes. When
matter undergoes a physical change, the
composition of the matter remains the same.