2.1 Classifying Matter
Do Now
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Identify the following:
C
H
O
H2O
CO2
NaCl
C6H12O6
What do they all have in common?
2.1 Classifying Matter
Do Now
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Identify the following:
C
Carbon
H
Hydrogen
O
Oxygen
H2O
Water
CO2
Carbon dioxide
NaCl
Sodium chloride
C6H12O6
Glucose
What do they all have in common? Made of atoms,
matter; are elements or are elements joined to make
a compound
2.1 Classifying Matter
Standards
• CLE 3202.1.1 Explore matter in terms of
its physical and chemical properties.
• CLE 3202.1.5 Evaluate pure substances
and mixtures.
• CLE 3202.1.4 Investigate chemical and
physical changes.
2.1 Classifying Matter
Objectives
• Classify pure substance
as elements or
compounds.
• Describe the
characteristics of an
element and the symbols
used to identify elements.
• Describe the
characteristics of a
compound.
• Distinguish pure
substances from
mixtures.
• Classify mixtures as
heterogeneous or
homogeneous.
• Classify mixtures as
solutions, suspensions, or
colloids.
2.1 Classifying Matter
Pure Substances
A pure substance is matter that always has
exactly the same composition.
• Table salt and table sugar are two
examples of pure substances.
• Substances can be classified into two
categories—elements and compounds.
Every sample of a given substance has the
same properties because a substance has
a fixed, uniform composition.
2.1 Classifying Matter
Elements
An element is a substance that cannot be
broken down into simpler substances.
An element has a fixed composition because
it contains only one type of atom.
No two elements contain the same type of atom.
2.1 Classifying Matter
Elements
Symbols for Elements
Chemists use symbols of one or two letters to
represent elements. The first letter is always
capitalized. If there is a second letter, it is not
capitalized.
Ex. C (carbon)
Al (aluminum)
Au (gold)
2.1 Classifying Matter
Compounds
A compound is a substance that is made from two
or more simpler substances and can be broken
down into those simpler substances (Elements or
other compounds.
A compound always contains two or more
elements joined in a fixed proportion.
Ex. H2O (water)
C6H12O6 (sucrose)
NaCl (salt)
Compounds must be
separated by some
chemical process!!
2.1 Classifying Matter
Frayer Model
2.1 Classifying Matter
TOTD
• Reviewing Concepts
• p. 44 #1-3
2.1 Classifying Matter
Do Now
• Identify the following mixtures as Homogeneous (HO) or
Heterogeneous (HE):
• Italian Dressing
• Apple juice
• Sand
• Kool-Aid
• Orange juice with pulp
• House Salad
• Black coffee
2.1 Classifying Matter
Mixtures
The properties of a mixture can vary
because the composition of a mixture is not
fixed.
• Mixtures can retain some of the properties of their
individual substances.
• The properties of a mixture are less constant than the
properties of a substance.
2.1 Classifying Matter
Do Now
• Identify the following mixtures as Homogeneous (HO) or
Heterogeneous (HE):
• Italian Dressing - (HE)
• Apple juice - (HO)
• Sand - (HE)
• Kool-Aid - (HO)
• Orange juice with pulp (HE)
• House Salad (HE)
• Black coffee - (HO)
• Think about the consistency of the 2 types mixtures. What
makes them different from each other?
2.1 Classifying Matter
Mixtures
Mixtures can be classified by how well the parts of the
mixture are distributed throughout the mixture.
Heterogeneous Mixtures
In a heterogeneous mixture, the parts of the mixture
are noticeably different from one another.
Homogeneous Mixtures
In a homogeneous mixture, the substances are so
evenly distributed that it is difficult to distinguish one
substance in the mixture from another.
2.1 Classifying Matter
Mixtures
The sand is a
heterogeneous mixture of
different kinds of grains.
The spoon is stainless
steel, a homogeneous
mixture of iron,
chromium, and nickel.
2.1 Classifying Matter
Solutions, Suspensions, and Colloids
Solutions
When substances dissolve and form a
homogeneous mixture, the mixture that forms
is called a solution.
Suspensions
A suspension is a heterogeneous mixture
that separates into layers over time.
2.1 Classifying Matter
Solutions, Suspensions, and Colloids
Colloids
A colloid contains some particles that are
intermediate in size between the small
particles in a solution and the larger particles
in a suspension.
• Like solutions, colloids do not separate into
layers.
• You cannot use a filter to separate the parts of a
colloid.
2.1 Classifying Matter
Solutions, Suspensions, and Colloids
These liquids represent three categories of
mixtures.
• Windshield wiper fluid is a solution.
• Muddy water collected from a swamp is a
suspension.
• Milk is a colloid.
2.1 Classifying Matter
Checks for Understanding
1. Which of these substances is a compound?
a.
b.
c.
d.
copper
water
oxygen
carbon
2.1 Classifying Matter
Checks for Understanding
1. Which of these substances is a compound?
a.
b.
c.
d.
copper
water
oxygen
carbon
ANS: B
2.1 Classifying Matter
Checks for Understanding
2. Which of these groups of letters could be used as
a symbol for an element?
a.
b.
c.
d.
HF
Cm
Car
fe
2.1 Classifying Matter
Checks for Understanding
2. Which of these groups of letters could be used as
a symbol for an element?
a.
b.
c.
d.
HF
Cm
Car
fe
ANS: B
2.1 Classifying Matter
Checks for Understanding
3. Which of the following statements does not apply
to a compound?
a. It is made of two or more elements.
b. It has components that are joined in fixed proportions.
c. It can be separated into components by physical
methods.
d. It can be broken down into elements or other
compounds.
2.1 Classifying Matter
Checks for Understanding
3. Which of the following statements does not apply
to a compound?
a. It is made of two or more elements.
b. It has components that are joined in fixed proportions.
c. It can be separated into components by physical
methods.
d. It can be broken down into elements or other
compounds.
ANS: C
2.1 Classifying Matter
Checks for Understanding
4. How does a compound differ from a mixture?
a. A compound cannot be broken down into simpler
substances.
b. Compounds can be separated by physical processes
and mixtures cannot.
c. The composition of a mixture cannot vary.
d. A compound is made of two or more elements in fixed
proportion.
2.1 Classifying Matter
Checks for Understanding
4. How does a compound differ from a mixture?
a. A compound cannot be broken down into simpler
substances.
b. Compounds can be separated by physical processes
and mixtures cannot.
c. The composition of a mixture cannot vary.
d. A compound is made of two or more elements in fixed
proportion.
ANS: D
2.1 Classifying Matter
Checks for Understanding
5. Which of these materials is a heterogeneous
mixture?
a.
b.
c.
d.
air
seawater
sand
steel
2.1 Classifying Matter
Checks for Understanding
5. Which of these materials is a heterogeneous
mixture?
a.
b.
c.
d.
air
seawater
sand
steel
ANS: C
2.1 Classifying Matter
Checks for Understanding
6. Which of the following can be separated with a
filter?
a.
b.
c.
d.
colloids
compounds
solutions
suspensions
2.1 Classifying Matter
Checks for Understanding
6. Which of the following can be separated with a
filter?
a.
b.
c.
d.
colloids
compounds
solutions
suspensions
ANS: D
2.1 Classifying Matter
Complete the classification of
matter worksheets.
2.1 Classifying Matter
TOTD
• Standardized Test Prep
• p. 65 #1, 5, 6