Lesson 1 | Substances and Mixtures
Lesson 1 | Substances and Mixtures Student Labs and Activities
Page 8
Content Vocabulary
9
Lesson Outline
10
MiniLab
12
Content Practice A
13
Content Practice B
14
School to Home
15
Key Concept Builders
16
Enrichment
20
Challenge
21
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
Launch Lab
Matter and Atoms
7
Name
Date
Launch Lab
Class
LESSON 1: 10 minutes
Can you always see the parts of materials? If you eat a pizza, you can see the cheese, the pepperoni, and the other parts it is made from. Can you always see the individual parts when you mix materials?
Procedure 1. Read and complete a lab safety form. 2. Observe the materials at the eight stations your teacher has set up.
3. Record in the Data and Observations section below the name and a short description of each material.
Data and Observations
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
Think About This 1. Classify Which materials have easily identifiable parts?
2.
8
Key Concept Is it always easy to see the parts of materials that are mixed? Explain.
Matter and Atoms
Name
Content Vocabulary
Date
Class
LESSON 1
Substances and Mixtures Directions: Explain the differences between the terms in each pair on the lines provided. Use complete sentences.
1. heterogeneous mixture; homogenous mixture
2. atom; element
3. element; compound
4. substance; mixture
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
5. molecule; atom
6. compound; molecule
7. individual; multiple
8. chemical change; physical change
9. matter; substance
Matter and Atoms
9
Name
Date
Class
Lesson Outline
LESSON 1
Substances and Mixtures A. What is matter? 1. Anything that has mass and takes up space is considered to be
.
2. Types of
, including heat, sound, and electricity, and such as magnetism and gravity are not matter.
B. What is matter made of? 1. The building blocks of matter are small particles called
.
2. The different ways that atoms combine with each other help us identify different types of
.
C. Classifying Matter 1. Scientists classify all matter into two main groups: and
.
2. The difference between the two main kinds of matter is their
.
1. Matter with a composition that is always the same is a(n)
.
2. A substance made up on only one kind of atom, such as gold is a(n)
.
a. Some elements are formed of
, which are units formed of two or more atoms that are held together by chemical bonds.
b. There are about 115 elements, each of which has its own chemical
.
3. A(n)
is a substance made up of two or more elements that are chemically joined in a specific combination; most matter is formed of
.
E. What is a mixture? 1. Matter that can vary in its composition is a(n) 2. The substances that make up
10
. are not bonded together.
Matter and Atoms
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
D. What is a substance?
Name
Date
Class
Lesson Outline continued F. Types of Mixtures 1. Mixtures differ in how
the substances that form them
are mixed.
2. A mixture, such as trail mix, in which the substances are not evenly mixed is a(n)
mixture.
3. A mixture in which two or more substances are evenly mixed, but not bonded together is a(n)
mixture, also called
a(n)
.
4. All three states of matter can be a(n)
or a solvent in
a solution.
G. Compounds v. Mixtures 1. The parts of any kind of
, including trail mix, soda,
and air, keep their properties.
2. The atoms that make up a(n)
are bonded together, so
its composition is always the same.
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
3. The substances that make up a(n)
are not bonded together, so adding more of one substance in a solution will not change the composition of the solution.
4. You can separate the parts of any mixture by using processes.
a. A(n)
, a strainer, or a ladle can be used to separate the
parts of a(n)
mixture.
b. The best methods for separating a(n) solution—is to use
mixture—a or evaporation.
H. Visualizing Classification of Matter 1. Matter can be classified as a(n) a(n)
or .
2. A substance can be classified as a(n) a(n)
or
.
3. A mixture can be classified as or
.
4. All the matter in every category is made up of
Matter and Atoms
.
11
Name
Date
MiniLab
Class
LESSON 1: 20 minutes
How do elements, compounds, and mixtures differ? The elements in a compound cannot be separated easily. However, you often can use the properties of the substances in a mixture to separate them.
Procedure 1. Read and complete a lab safety form. 2. Observe samples of sand and iron filings with a magnifying lens. Record your observations in the Data and Observations section below.
3. Combine the sand and iron filings in a clear cup. Stir with a toothpick.
Observe the mixture with the magnifying lens. Record your observations.
4. Cover one end of a magnet with plastic wrap. Stir the mixture with the covered magnet. Record your observations.
Data and Observations
1. Classify The formula for sand is SiO2. The symbol for iron is Fe. Use this to classify each as an element, a compound, or a mixture.
2.
Key Concept What are two ways you could tell from your observations that the combination of sand and iron filings is a mixture and not a substance?
12
Matter and Atoms
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
Analyze and Conclude
Name
Date
Class
Content Practice A
LESSON 1
Substances and Mixtures Directions: Use the clues to complete the crossword puzzle. 1
4
2
5 3
6
7
8
Clues
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
Across 1. a mixture in which two or more substances are evenly mixed but not bonded together
6. a mixture in which the substances are not evenly mixed
7. two or more atoms that are held together by chemical bonds and act as a unit
8. matter with a composition that is
Down 2. anything that has mass and takes up space
3. substance made of only one kind of atom
4. a small particle that is the building block of matter
5. substance made of two or more elements that are chemically joined in a specific combination
always the same
Matter and Atoms
13
Name
Date
Class
Content Practice B
LESSON 1
Substances and Mixtures Directions: On the line before each statement, write T if the statement is true or F if the statement is false. If the statement is false, change the underlined word(s) to make it true. Write your changes on the lines provided.
1. Gravity is matter because it does not have mass and volume.
2. Each type of atom has a different number of smaller particles.
3. The composition of a substance is always the same.
4. The substances in a mixture are bonded together.
5. All atoms of an element are alike.
7. Elements can be classified as metals, nonmetals, and metalloids.
8. Compounds are made of atoms of the same element bonded together.
9. Soda is an example of a heterogeneous mixture, or a mixture in which two or more substances are evenly mixed but not bonded together.
14
Matter and Atoms
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
6. The atoms in a molecule are held together by chemical bonds.
Name
Date
Class
School to Home
LESSON 1
Substances and Mixtures Directions: Use your textbook to complete the activity.
Use the word bank below to complete the concept map describing how matter is classified.
compounds
elements
heterogeneous mixtures
homogeneous mixtures
mixtures
substance
Matter can be classified as
a.
b.
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
which can be
c.
which can be
d.
e.
f.
which are
which are
in which
in which
made up of only one kind of atom.
two or more kinds of atoms chemically joined in specific combinations.
the components are not evenly mixed.
two or more components are evenly mixed but not bonded.
Matter and Atoms
15
Name
Date
Class
Key Concept Builder
LESSON 1
Substances and Mixtures Key Concept What is the relationship among atoms, elements, and compounds? Directions: Answer each question or respond to each statement in the space provided.
1. What is an atom?
2. What happens when atoms combine?
3. What is an element?
4. Name three elements.
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
5. What is the relationship among atoms, elements, and molecules?
6. What is a compound?
7. Name three compounds.
8. What information about a compound is found in its chemical formula? 9. How are atoms related to elements and compounds?
16
Matter and Atoms
Name
Date
Key Concept Builder
Class
LESSON 1
Substances and Mixtures Key Concept How are some mixtures different from solutions?
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
Directions: On the line before each item, write HE if the item represents a heterogeneous mixture or HO if the item represents a homogeneous mixture.
1.
granite
2.
smoke
3.
soda
4.
brass
5.
trail mix
6.
air
7.
tap water
Directions: Answer each question on the lines provided.
8. What is the difference between a heterogeneous mixture and a homogeneous mixture?
9. Which mixtures listed in the activity above are solutions? Explain your answer.
Matter and Atoms
17
Name
Date
Class
Key Concept Builder
LESSON 1
Substances and Mixtures Key Concept How do mixtures and compounds differ? Directions: Complete the chart by writing the correct term from the word bank on the lines provided. Some terms may be used more than once or not at all.
atoms
compounds
elements
heterogeneous mixture
homogeneous mixture
mass
matter
mixtures
substances
Matter • anything that has (1.)
and takes up space
• most made of (2.) • two classifications: (3.)
and (4.)
(5.) • made up of one or more types of atoms in the same combinations • two types: (6.)
and (7.)
(9.)
• made of only one type of atom • organized on the periodic table
• made of two or more types of atoms bonded together • properties are different from the elements that make it up
• have a chemical symbol
• have chemical formulas
(10.) • made of two or more (11.)
that are not bonded together
• Combinations of subtances can vary. • two types: (12.)
(14.)
and (13.)
(15.)
• two or more substances unevenly mixed
• two or more substances evenly mixed
• different substances visible by unaided eye or microscope
• Different substances cannot be seen by a microscope.
18
Matter and Atoms
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
(8.)
Name
Date
Class
Key Concept Builder
LESSON 1
Substances and Mixtures Key Concept How do mixtures and compounds differ? Directions: Put a check mark on the line before each property that is typical of a compound.
1. made of only one kind of atom 2. made of unbonded substances 3. is a substance 4. made of elements that are bonded together 5. represented by a chemical formula 6. Identity is not changed by changing the amount of its substances.
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
7. is the smallest part of an element 8. is often made of molecules Directions: Respond to each statement on the lines provided.
9. Compare the composition of a mixture and a compound.
10. Compare what happens when you change the composition of a mixture and a compound.
Matter and Atoms
19
Name
Date
Enrichment
Class
LESSON 1
Categorizing Mixtures Aerosol cans are often used to apply paint to small surfaces. The gas in the can is under pressure. When you press the button, the gas escapes, carrying droplets of paint outward.
Suspensions
Colloids
In a suspension, one substance is finely divided and temporarily suspended throughout another substance. Particles in a suspension are often large enough to see. The substances can be mixed by shaking, but the dispersed substance eventually settles out because of the particle size. Common suspensions include sand in water or Italian salad dressing. Because of their size, particles of a suspension can often be separated through a filter. For example, you could use filter paper to separate the solids from the liquids in salad dressing. People use filters on a furnace to clean the dust particles from air and prevent them from settling on surfaces around the house. A suspension of liquid droplets or fine solid particles in a gas is called an aerosol. In the atmosphere, these consist of fine dust and soot particles that appear as haze, smog, or air pollution.
A colloid is a permanent suspension. The particles of the suspended substance are larger than particles in a solution but smaller than those in a suspension. Because they are so tiny, they don’t settle out. They remain suspended and cannot be filtered out. Gelatin and milk are colloids. If you shine a flashlight through gelatin or through water containing a few drops of milk, you can see the beam of light because it reflects from the particles. An emulsion is a type of colloid in which the two substances normally form a suspension. For example, oil and water form a suspension that eventually separates. If another substance is added that breaks the oil into colloid size particles, an emulsion forms. Examples of an emulsion are mayonnaise, butter, and margarine. The parts in a colloid can be solids, liquids, or gases, although there is no colloid of a gas in a gas.
Applying Critical-Thinking Skills Directions: Answer each question.
1. Distinguish What distinguishes a suspension and a colloid? What distinguishes a colloid and a solution?
2. Observe You have two glasses of red liquid. One is red food coloring dissolved in water. The other is red gelatin dissolved in water. How can you tell which glass holds the gelatin?
3. Infer If you shine a flashlight through air in a darkened room, you can see that the air is filled with tiny particles of dust. What would determine whether this dust is a suspension or a colloid?
20
Matter and Atoms
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
You have learned that a mixture can be heterogeneous or homogenous. Mixtures are also classified based on the size and distribution of the solute particles.
Name
Challenge
Date
Class
LESSON 1
Pure Water Many people around the world have a shortage of freshwater, but live near oceans. Oceans contain pure water, many different dissolved salts, microscopic sea animals, and bits of wood, plants, and rock.
Design a Procedure to Purify Seawater
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
Design a procedure to separate the pure water in seawater from the other materials in it. Keep in mind that, in many poor countries, electricity is not as readily available as it is in the United States. Make your procedure as simple as possible so the average person could do it to obtain freshwater. Outline your design in the space below. Draw a diagram of the procedure and label each part clearly so that anyone could follow it to obtain freshwater.
Matter and Atoms
21
Page 8
Content Vocabulary
9
Lesson Outline
10
MiniLab
12
Content Practice A
13
Content Practice B
14
School to Home
15
Key Concept Builders
16
Enrichment
20
Challenge
21
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
Launch Lab
Matter and Atoms
7
Name
Date
Launch Lab
Class
LESSON 1: 10 minutes
Can you always see the parts of materials? If you eat a pizza, you can see the cheese, the pepperoni, and the other parts it is made from. Can you always see the individual parts when you mix materials?
Procedure 1. Read and complete a lab safety form. 2. Observe the materials at the eight stations your teacher has set up.
3. Record in the Data and Observations section below the name and a short description of each material.
Data and Observations
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
Think About This 1. Classify Which materials have easily identifiable parts?
2.
8
Key Concept Is it always easy to see the parts of materials that are mixed? Explain.
Matter and Atoms
Name
Content Vocabulary
Date
Class
LESSON 1
Substances and Mixtures Directions: Explain the differences between the terms in each pair on the lines provided. Use complete sentences.
1. heterogeneous mixture; homogenous mixture
2. atom; element
3. element; compound
4. substance; mixture
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
5. molecule; atom
6. compound; molecule
7. individual; multiple
8. chemical change; physical change
9. matter; substance
Matter and Atoms
9
Name
Date
Class
Lesson Outline
LESSON 1
Substances and Mixtures A. What is matter? 1. Anything that has mass and takes up space is considered to be
.
2. Types of
, including heat, sound, and electricity, and such as magnetism and gravity are not matter.
B. What is matter made of? 1. The building blocks of matter are small particles called
.
2. The different ways that atoms combine with each other help us identify different types of
.
C. Classifying Matter 1. Scientists classify all matter into two main groups: and
.
2. The difference between the two main kinds of matter is their
.
1. Matter with a composition that is always the same is a(n)
.
2. A substance made up on only one kind of atom, such as gold is a(n)
.
a. Some elements are formed of
, which are units formed of two or more atoms that are held together by chemical bonds.
b. There are about 115 elements, each of which has its own chemical
.
3. A(n)
is a substance made up of two or more elements that are chemically joined in a specific combination; most matter is formed of
.
E. What is a mixture? 1. Matter that can vary in its composition is a(n) 2. The substances that make up
10
. are not bonded together.
Matter and Atoms
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
D. What is a substance?
Name
Date
Class
Lesson Outline continued F. Types of Mixtures 1. Mixtures differ in how
the substances that form them
are mixed.
2. A mixture, such as trail mix, in which the substances are not evenly mixed is a(n)
mixture.
3. A mixture in which two or more substances are evenly mixed, but not bonded together is a(n)
mixture, also called
a(n)
.
4. All three states of matter can be a(n)
or a solvent in
a solution.
G. Compounds v. Mixtures 1. The parts of any kind of
, including trail mix, soda,
and air, keep their properties.
2. The atoms that make up a(n)
are bonded together, so
its composition is always the same.
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
3. The substances that make up a(n)
are not bonded together, so adding more of one substance in a solution will not change the composition of the solution.
4. You can separate the parts of any mixture by using processes.
a. A(n)
, a strainer, or a ladle can be used to separate the
parts of a(n)
mixture.
b. The best methods for separating a(n) solution—is to use
mixture—a or evaporation.
H. Visualizing Classification of Matter 1. Matter can be classified as a(n) a(n)
or .
2. A substance can be classified as a(n) a(n)
or
.
3. A mixture can be classified as or
.
4. All the matter in every category is made up of
Matter and Atoms
.
11
Name
Date
MiniLab
Class
LESSON 1: 20 minutes
How do elements, compounds, and mixtures differ? The elements in a compound cannot be separated easily. However, you often can use the properties of the substances in a mixture to separate them.
Procedure 1. Read and complete a lab safety form. 2. Observe samples of sand and iron filings with a magnifying lens. Record your observations in the Data and Observations section below.
3. Combine the sand and iron filings in a clear cup. Stir with a toothpick.
Observe the mixture with the magnifying lens. Record your observations.
4. Cover one end of a magnet with plastic wrap. Stir the mixture with the covered magnet. Record your observations.
Data and Observations
1. Classify The formula for sand is SiO2. The symbol for iron is Fe. Use this to classify each as an element, a compound, or a mixture.
2.
Key Concept What are two ways you could tell from your observations that the combination of sand and iron filings is a mixture and not a substance?
12
Matter and Atoms
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
Analyze and Conclude
Name
Date
Class
Content Practice A
LESSON 1
Substances and Mixtures Directions: Use the clues to complete the crossword puzzle. 1
4
2
5 3
6
7
8
Clues
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
Across 1. a mixture in which two or more substances are evenly mixed but not bonded together
6. a mixture in which the substances are not evenly mixed
7. two or more atoms that are held together by chemical bonds and act as a unit
8. matter with a composition that is
Down 2. anything that has mass and takes up space
3. substance made of only one kind of atom
4. a small particle that is the building block of matter
5. substance made of two or more elements that are chemically joined in a specific combination
always the same
Matter and Atoms
13
Name
Date
Class
Content Practice B
LESSON 1
Substances and Mixtures Directions: On the line before each statement, write T if the statement is true or F if the statement is false. If the statement is false, change the underlined word(s) to make it true. Write your changes on the lines provided.
1. Gravity is matter because it does not have mass and volume.
2. Each type of atom has a different number of smaller particles.
3. The composition of a substance is always the same.
4. The substances in a mixture are bonded together.
5. All atoms of an element are alike.
7. Elements can be classified as metals, nonmetals, and metalloids.
8. Compounds are made of atoms of the same element bonded together.
9. Soda is an example of a heterogeneous mixture, or a mixture in which two or more substances are evenly mixed but not bonded together.
14
Matter and Atoms
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
6. The atoms in a molecule are held together by chemical bonds.
Name
Date
Class
School to Home
LESSON 1
Substances and Mixtures Directions: Use your textbook to complete the activity.
Use the word bank below to complete the concept map describing how matter is classified.
compounds
elements
heterogeneous mixtures
homogeneous mixtures
mixtures
substance
Matter can be classified as
a.
b.
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
which can be
c.
which can be
d.
e.
f.
which are
which are
in which
in which
made up of only one kind of atom.
two or more kinds of atoms chemically joined in specific combinations.
the components are not evenly mixed.
two or more components are evenly mixed but not bonded.
Matter and Atoms
15
Name
Date
Class
Key Concept Builder
LESSON 1
Substances and Mixtures Key Concept What is the relationship among atoms, elements, and compounds? Directions: Answer each question or respond to each statement in the space provided.
1. What is an atom?
2. What happens when atoms combine?
3. What is an element?
4. Name three elements.
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
5. What is the relationship among atoms, elements, and molecules?
6. What is a compound?
7. Name three compounds.
8. What information about a compound is found in its chemical formula? 9. How are atoms related to elements and compounds?
16
Matter and Atoms
Name
Date
Key Concept Builder
Class
LESSON 1
Substances and Mixtures Key Concept How are some mixtures different from solutions?
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
Directions: On the line before each item, write HE if the item represents a heterogeneous mixture or HO if the item represents a homogeneous mixture.
1.
granite
2.
smoke
3.
soda
4.
brass
5.
trail mix
6.
air
7.
tap water
Directions: Answer each question on the lines provided.
8. What is the difference between a heterogeneous mixture and a homogeneous mixture?
9. Which mixtures listed in the activity above are solutions? Explain your answer.
Matter and Atoms
17
Name
Date
Class
Key Concept Builder
LESSON 1
Substances and Mixtures Key Concept How do mixtures and compounds differ? Directions: Complete the chart by writing the correct term from the word bank on the lines provided. Some terms may be used more than once or not at all.
atoms
compounds
elements
heterogeneous mixture
homogeneous mixture
mass
matter
mixtures
substances
Matter • anything that has (1.)
and takes up space
• most made of (2.) • two classifications: (3.)
and (4.)
(5.) • made up of one or more types of atoms in the same combinations • two types: (6.)
and (7.)
(9.)
• made of only one type of atom • organized on the periodic table
• made of two or more types of atoms bonded together • properties are different from the elements that make it up
• have a chemical symbol
• have chemical formulas
(10.) • made of two or more (11.)
that are not bonded together
• Combinations of subtances can vary. • two types: (12.)
(14.)
and (13.)
(15.)
• two or more substances unevenly mixed
• two or more substances evenly mixed
• different substances visible by unaided eye or microscope
• Different substances cannot be seen by a microscope.
18
Matter and Atoms
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
(8.)
Name
Date
Class
Key Concept Builder
LESSON 1
Substances and Mixtures Key Concept How do mixtures and compounds differ? Directions: Put a check mark on the line before each property that is typical of a compound.
1. made of only one kind of atom 2. made of unbonded substances 3. is a substance 4. made of elements that are bonded together 5. represented by a chemical formula 6. Identity is not changed by changing the amount of its substances.
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
7. is the smallest part of an element 8. is often made of molecules Directions: Respond to each statement on the lines provided.
9. Compare the composition of a mixture and a compound.
10. Compare what happens when you change the composition of a mixture and a compound.
Matter and Atoms
19
Name
Date
Enrichment
Class
LESSON 1
Categorizing Mixtures Aerosol cans are often used to apply paint to small surfaces. The gas in the can is under pressure. When you press the button, the gas escapes, carrying droplets of paint outward.
Suspensions
Colloids
In a suspension, one substance is finely divided and temporarily suspended throughout another substance. Particles in a suspension are often large enough to see. The substances can be mixed by shaking, but the dispersed substance eventually settles out because of the particle size. Common suspensions include sand in water or Italian salad dressing. Because of their size, particles of a suspension can often be separated through a filter. For example, you could use filter paper to separate the solids from the liquids in salad dressing. People use filters on a furnace to clean the dust particles from air and prevent them from settling on surfaces around the house. A suspension of liquid droplets or fine solid particles in a gas is called an aerosol. In the atmosphere, these consist of fine dust and soot particles that appear as haze, smog, or air pollution.
A colloid is a permanent suspension. The particles of the suspended substance are larger than particles in a solution but smaller than those in a suspension. Because they are so tiny, they don’t settle out. They remain suspended and cannot be filtered out. Gelatin and milk are colloids. If you shine a flashlight through gelatin or through water containing a few drops of milk, you can see the beam of light because it reflects from the particles. An emulsion is a type of colloid in which the two substances normally form a suspension. For example, oil and water form a suspension that eventually separates. If another substance is added that breaks the oil into colloid size particles, an emulsion forms. Examples of an emulsion are mayonnaise, butter, and margarine. The parts in a colloid can be solids, liquids, or gases, although there is no colloid of a gas in a gas.
Applying Critical-Thinking Skills Directions: Answer each question.
1. Distinguish What distinguishes a suspension and a colloid? What distinguishes a colloid and a solution?
2. Observe You have two glasses of red liquid. One is red food coloring dissolved in water. The other is red gelatin dissolved in water. How can you tell which glass holds the gelatin?
3. Infer If you shine a flashlight through air in a darkened room, you can see that the air is filled with tiny particles of dust. What would determine whether this dust is a suspension or a colloid?
20
Matter and Atoms
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
You have learned that a mixture can be heterogeneous or homogenous. Mixtures are also classified based on the size and distribution of the solute particles.
Name
Challenge
Date
Class
LESSON 1
Pure Water Many people around the world have a shortage of freshwater, but live near oceans. Oceans contain pure water, many different dissolved salts, microscopic sea animals, and bits of wood, plants, and rock.
Design a Procedure to Purify Seawater
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
Design a procedure to separate the pure water in seawater from the other materials in it. Keep in mind that, in many poor countries, electricity is not as readily available as it is in the United States. Make your procedure as simple as possible so the average person could do it to obtain freshwater. Outline your design in the space below. Draw a diagram of the procedure and label each part clearly so that anyone could follow it to obtain freshwater.
Matter and Atoms
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