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C03_036A
Heterogeneous
mixtures
dirt, blood,
milk
lemonade,
gasoline, steel
oxygen, gold,
iron
salt, baking soda,
sugar
Homogeneous
mixtures
Elements
Compounds
Physical
changes
Pure substances
Mixtures
Matter
Chemical
changes
Figure 20
Matter can be classified into different categories that have defined properties.
Examine
How are mixtures and substances related? Elements and compounds?
Recall what you have learned about the organization of matter. Matter is classified as
pure substances and mixtures. An element is a pure substance that cannot be separated
into simpler substances, whereas a compound is a chemical combination of two or more
elements and can be separated into its components. A mixture can be homogeneous or
heterogeneous.
Figure 20
summarizes the classification of matter and how these com-
ponents are related to one another.
Separating Mixtures
Most matter exists naturally in the form of mixtures. To gain a thorough understanding of
matter, it is important to be able to separate mixtures into their component substances.
Because the substances in a mixture are physically combined, the processes used to
separate a mixture are physical processes that are based on differences in the physical
properties of the substances. For instance, a mixture of iron and sand can be separated
into its components with a magnet because a magnet will attract iron but not sand.
Numerous techniques have been developed that take advantage of different physical
properties in order to separate various mixtures.
Get It?
Summarize
the different types of matter and how they are related to each other.
STEM CAREER Connection
High School Chemistry Teacher
Do you enjoy helping others? Do you like chemistry? Are you able to effectively
explain yourself when talking to others? You may wish to consider a career
teaching high school chemistry. High school teachers prepare students for life after
high school. They prepare students to be valuable members of society by teaching
lessons and skills needed to be successful in post-secondary education or to enter
the workforce.
WORD ORIGIN
mixture
from the Latin word
misceo,
meaning
to
mix
or
blend
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Module 2 • Matter—Properties and Changes