1 chapter 3atoms and elements 3.1 classification of matter copyright © 2009 by pearson education,...
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Chapter 3 Atoms and Elements
3.1Classification of Matter
Copyright © 2009 by Pearson Education, Inc.
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Matter
Matter is the “stuff” that makes up all things.
Copyright © 2009 by Pearson Education, Inc.
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A pure substance is classified as
• matter with a specific composition.
• an element when composed of one type of atom.
• a compound when composed of two or more elements combined in a definite ratio.
Pure Substances
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Elements
Elements are • pure substances that
contains atoms of only one type.
Copper, Cu
Lead, Pb
Aluminum, Al
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Compounds
Compounds
• contain two or more elements in a definite ratio.
Salt (NaCl)
Table sugar (C12H22O11)
Water (H2O)
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Elements in a Compound
“Table salt” is a compound that contains the elements sodium and chlorine.
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Mixtures
A mixture is a type of matter that consists of
• two or more substances that are physically mixed, not chemically combined.
• two or more substances in different proportions.
• substances that can be separated by physical methods.
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Physical Separation of a Mixture
Example:
Pasta and water are separated with a strainer.
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Homogeneous Mixtures
In a homogeneous mixture,
• the composition is uniform
throughout.• the different parts of the
mixture are not visible.
Copyright © 2009 by Pearson Education, Inc.
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Heterogeneous Mixtures
In a heterogeneous mixture, • the composition of
substances is not uniform.• the composition varies from
one part of the mixture to another.
• the different parts of the mixture are visible.
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Classification of Matter
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Identify each of the following as a pure substance or a mixture.
A. pasta and tomato sauce
B. aluminum foil
C. helium
D. air
Learning Check
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Identify each of the following as a pure substance or a mixture.
A. pasta and tomato saucemixture
B. aluminum foil pure substance
C. helium pure substance
D. air mixture
Solution
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Identify each of the following as a homogeneous orheterogeneous mixture:
A. hot fudge sundae
B. air
C. sugar water
D. peach pie
Learning Check
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Identify each of the following as a homogeneous orheterogeneous mixture:
A. hot fudge sundae heterogeneous mixture
B. air homogeneous mixture
C. sugar water homogeneous mixture
D. peach pie heterogeneous mixture
Solution