Transcript What are pure substances?

Unit 1 Lesson 4 Pure Substances and Mixtures
Essential question: How do pure substances and
mixtures compare?
Copyright © Houghton Mifflin Harcourt Publishing Company
Unit 1 Lesson 4 Pure Substances and Mixtures
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A Great Combination
How can matter be classified?
• Matter is made up of basic “ingredients” known as
atoms.
• An atom is the smallest unit of an element that
maintains the properties of that element.
• Substances are classified as elements, compounds,
and mixtures.
Basic ingredients
of all “stuff”
Substances are
classified as:
Matter
Elements
Compounds
Mixtures
Unit 1 Lesson 4 Pure Substances and Mixtures
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How can matter be classified?
• An atom is a building block of
matter
• An element is made of only one
kind of atom.
•A compound is made up of different kinds of
atoms that are chemically combined.
•A mixture contains a variety of elements
and compounds that are not chemically
combined.
Unit 1 Lesson 4 Pure Substances and Mixtures
How can matter be classified?
• Is water an element, a compound, or a mixture?
Active reading #5
They are all made up of atoms
Visualize it #7
2 different colors represent 2 different types of atoms
Unit 1 Lesson 4 Pure Substances and Mixtures
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Unit 1 Lesson 4 Pure Substances and Mixtures
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Pure Genius
What are pure substances?
• A pure substance is a substance with definite physical and
chemical properties.
• Pure substances are made up of just one type of particle.
• Examples: Elements and compounds
• Physical changes such as melting, freezing, cutting, or
smashing do not change the identity of pure
substances.
• When a pure substance undergoes a chemical change, it
is no longer that same substance.
11) Identify
The chemical bonds that hold the atoms together are
broken. A new substance is formed
Unit 1 Lesson 4 Pure Substances and Mixtures
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Pure Genius
What are pure substances?
8) Identify: A) Copper ATOMS B) Water Molecules
9) Explain:
Atoms that make
up copper are all
the same type
10) Explain:
Water is made up of two
different types of atoms
that are joined together.
The molecules that make
up water are all the same
Matter
Pure
Substances
Elements
Metals
Nonmetals
Metalloids
Mixtures
Compounds
Unit 1 Lesson 4 Pure Substances and Mixtures
What are pure substances?
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Unit 1 Lesson 4 Pure Substances and Mixtures
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Classified Information
How can elements be classified?
• Elements are classified as metals, nonmetals, or
metalloids.
• Metals: shiny, conduct
electricity, malleable, ductile
• Nonmetals: not shiny, do
not conduct electricity or
heat.
• Metalloids: have properties
of both
• Classifying elements helps scientists predict the
properties of elements.
• The periodic table is a tool used to classify and
identify elements that have similar properties.
Matter
Pure
Substances
Elements
Metals
Nonmetals
Metalloids
Mixtures
Compounds
pH
Organic or
Inorganic
Role in the
body
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How can compounds be classified?
• Compounds can be classified as acidic, basic, or
neutral by measuring pH.
• Pure water (Neutral) has a pH of 7
• Acids have a pH below 7.
• Blue litmus paper turns red in the presence of an acid.
• Bases have a pH above 7.
• Red litmus paper turns blue in the presence of a base.
- Describing Acids and Bases
Properties of Acids and Bases
Litmus is an example of an indicator, a
compound that changes color when in
contact with an acid or a base.
Online Activity
Unit 1 Lesson 4 Pure Substances and Mixtures
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How can compounds be classified?
• Compounds can be organic or inorganic.
• Organic compounds are those that contain carbon and
hydrogen.
• Organic compounds made by living things are
called biochemicals.
• Carbohydrates, lipids, proteins, and nucleic
acids are biochemical compounds.
Matter
Pure
Substance
s
Compound
s
Elements
Metals
Nonmetals
Metalloids
Mixtures
pH
Acid
Organic or
inorganic
Base
Role in the
body
Biochemicals
<7
>7
Carbohydrates
Blue litmus
turns red
Red litmus
turns blue
Lipids
Proteins
Nucleic
acids
Unit 1 Lesson 4 Pure Substances and Mixtures
Mix and Match
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What are mixtures?
• A mixture is a combination of two or more
substances that are combined physically
but not chemically.
• Mixtures are not pure substances and do
not have definite properties.
• Substances within a mixture keep their
identities and individual properties.
• Mixtures can be separated by physical
changes, although some mixtures are
difficult to separate.
•Magnets, centrifuges, filters, and
other materials can be used to
separate mixtures.
Unit 1 Lesson 4 Pure Substances and Mixtures
14) Visualize
A) Sand and
salt are poured
into a single
beaker. The
result is a
mixture
because
B) When water
is added to the
sand-salt
mixture,
They are not
chemically
combined
Salt dissolves
in water. Sand
does not.
C) When the
liquid is
poured
through a filter,
Salt water
passes
through the
filter
D) The
remaining salt
water is
heated until
Water is
boiled off
(evaporated)
leaving salt
behind
15) Devise
Pick out the rocks by hand. Sort by size
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Simple Solution
How can mixtures be classified?
•A heterogeneous
mixture is one that
does not have a
uniform composition.
• A homogeneous
mixture has the same
composition throughout.
Unit 1 Lesson 4 Pure Substances and Mixtures
How can mixtures be classified?
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• A suspension is a heterogeneous
mixture.
• Particles in a suspension are spread
throughout a liquid or gas, but are
too large to stay mixed unless
shaken or stirred.
• Particles settle in suspensions.
• A solution is a homogeneous
mixture in which one substance is
dissolved in another substance.
• Colloids have particles that are
unevenly spread throughout the
mixture. (looks homogenous but
really heterogeneous)
• particles in colloids are too small to
settle out of the mixture.
Matter
Pure
Substances
Mixtures
Elements
Compounds
Metals
Nonmetals
Metalloids
Organic or
inorganic
pH
Acid
Base
Heterogeneous
Role in the
body
Biochemicals
Suspensions
Particles are
spread
throughout
<7
>7
Carbohydrates
Blue litmus
turns red
Red litmus
turns blue
Lipids
too large to
stay mixed
unless
shaken or
stirred
Proteins
Particles
settle
Nucleic acids
Colloids
particles
that are
unevenly
spread
throughout
particles in
colloids are
too small to
settle out of
the mixture
Homogenous
Solutions
one
substance is
dissolved in
another
substance
Mixtures
Heterogeneous
Suspensions
Particles are
spread
throughout
too large to
stay mixed
unless
shaken or
stirred
Particles settle
Colloids
particles
that are
unevenly
spread
throughout
particles in
colloids are
too small to
settle out of
the mixture
Homogenous
Solutions
one
substance is
dissolved in
another
substance
Elements
Compounds
Unit 1 Lesson 4 Pure Substances and Mixtures
Are
made up
of atoms
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