Section 3.3 Mixtures of Matter
• Contrast mixtures and substances.
• Classify mixtures as homogeneous or
heterogeneous.
• List and describe several techniques used to
separate mixtures.
substance: a form of matter that has a uniform and
unchanging composition; also known as a pure
substance
Section 3.3 Mixtures of Matter (cont.)
mixture
distillation
heterogeneous mixture
crystallization
homogeneous mixture
sublimation
solution
chromatography
filtration
Most everyday matter occurs as
mixtures—combinations of two or more
substances.
Section 3.1 Properties of Matter
3.3 ESSENTIAL QUESTION:
What are the different types of
mixtures and how do you
separate them?
Mixtures
• A mixture is a combination of two or more
pure substances in which each pure
substance retains its individual chemical
properties.
• A homogenous mixture is a mixture where
the composition is constant throughout.
Mixtures (cont.)
• Homogeneous mixtures are also called
solutions.
• A heterogeneous mixture is a mixture where
the individual substances remain distinct.
Mixtures (cont.)
Separating Mixtures
• Filtration is a technique that uses a porous
barrier to separate a solid from a liquid in a
heterogeneous mixture.
• Distillation is a separation technique for
homogeneous mixtures that is based on the
differences in boiling points of substances.
• Crystallization is a separation technique for
homogenous mixtures that results in the
formation of pure solid particles from a
solution containing the dissolved substance.
Separating Mixtures (cont.)
• Sublimation is the process of a solid
changing directly to a gas, which can be
used to separate mixtures of solids when
one sublimates and the other does not.
• Chromatography is a technique that
separates the components of a mixture on
the basis of tendency of each to travel across
the surface of another material.
Section 3.3 Assessment
Which is NOT a technique for separating a
homogenous mixture?
A. crystallization
B. distillation
D
A
0%
C
D. chromatography
A. A
B. B
C. C
0%
0%
0%
D. D
B
C. filtration
Section 3.3 Assessment
Which of the following is a heterogeneous
mixture?
A. seawater
B. silver mercury amalgam
D
A
0%
C
D. salad dressing
A. A
B. B
C. C
0%
0%
0%
D. D
B
C. atmosphere
Section 3.4 Elements and Compounds
• Distinguish between elements and compounds.
• Describe the organization of elements in the periodic
table.
• Explain how all compounds obey the laws of definite
and multiple proportions.
proportion: the relation of one part to another or
to the whole with respect to quantity
Section 3.4 Elements and Compounds
(cont.)
element
law of definite proportions
periodic table
percent by mass
compound
law of multiple proportions
A compound is a combination of two or
more elements.
Section 3.1 Properties of Matter
3.4 ESSENTIAL QUESTION:
How are mixtures, substances,
elements & compounds related?
Elements
• An element is a pure substance that cannot
be separated into simpler substances by
physical or chemical means.
• 92 elements occur naturally on Earth.
• Each element has a unique name and a one,
two, or three-letter symbol.
• The periodic table organizes the elements
into a grid of horizontal rows called periods
and vertical columns called groups.
Compounds
• A compound is a made up of two or more
elements combined chemically.
• Most of the matter in the universe exists as
compounds.
• Table salt, NaCl, and water, H2O, are
compounds.
Compounds (cont.)
• Elements can never be separated.
• Compounds can be broken into components
by chemical means.
Compounds (cont.)
• This figure shows
electrolysis of
water to form
hydrogen and
oxygen.
Compounds (cont.)
• The properties of a compound are different
from its component elements.