(page 10-11)
A. Matter: Substances and Mixtures
1. There are two main categories of matter: substances and mixtures.
2. Matter that is always made up of the same combination of atoms is defined as a(n)
substance.
a. The two kinds of substances are elements and compounds.
b. A substance that is made up of only one kind of atom, such as oxygen, is a(n) element.
c. Atoms of two or more elements chemically bonded together, such as water, form (a)n
compound.
3. Atoms of two or more substances that are physically blended but are not chemically bonded
together form a(n) mixture.
a. The relative amounts of the substances that form a(n) mixture can vary.
b. Granite is an example of a mixture that is a solid.
c. Air is an example of a mixture of gases.
d. A mixture in which substances are not evenly mixed, such as granite or blood, is called a(n)
heterogeneous mixture.
e. A mixture in which two or more substances are evenly mixed on the atomic level but not
bonded together is called a(n) homogeneous mixture.
f. When you look at a(n) homogeneous mixture with or without a(n) microscope, all the parts
look the same.
g. A homogeneous mixture can also be called a(n) solution; these terms mean the same thing.
B. How do compounds and mixtures differ?
1. The formation of a(n) compound occurs due to a chemical change.
2. Mixing is a(n) physical change, so the substances that exist before mixing also exist in the
mixture.
a. A(n) mixture has some of the same physical properties as the substances that make up the
mixture.
b. A(n) compound, in contrast, has physical properties different from the properties of the
substances that make up the compound.
3. The substances that form a(n) mixture are not chemically bonded to one another.
a. The substances that are combined in a mixture can be separated from one another using
physical means.
b. In contrast, the substances that form a(n) compound are bonded chemically, so the only way
to separate them is to break the chemical bonds—which is a(n) chemical change.
(Page 13)
Directions: Complete the chart by writing words or phrases from the word bank in the correct
column.
also called solutions blood
can see different parts with an evenly mixed but not bonded
unaided eye granite
fruit salad one color and texture
looks the same throughout soil
salt water sugar water
substances not evenly mixed
1-6 (in any order) granite; 7–12. (in any order) also
called solutions;
salt water;
substances not evenly
mixed;
blood; evenly mixed but not
bonded;
soil;
sugar water;
looks the same throughout;
can see different parts with
an unaided eye;
one color and texture
fruit salad
(page 14)
Directions: Circle the term in parentheses that correctly completes each sentence.
1. Almost all matter can be classified into two major categories—substances and (compounds,
mixtures).
2. Matter that is made up of the same combination of atoms is called a (substance, mixture).
3. Substances that are physically blended but not chemically bonded together are called
(compounds, mixtures).
4. Mixtures have (exact, relative) amounts of the same substances.
5. Two types of mixtures are homogeneous and (solutions, heterogeneous).
6. Matter that is made up of chemically bonded atoms from two or more elements is called a
(compound, solution).
7. An example of a homogeneous solution is (granite, salt water).
8. Properties of a (compound, mixture) can be different from the properties of its elements.
9. The properties found in a (mixture, element) are the same before and after mixing has taken
place.
10. Physical methods can separate (mixtures, compounds).
11. A chemical change is needed to separate (compounds, solutions).
12. Some of the properties of the (substances, compounds) that make up a mixture can be
observed in the mixture.
13. Air is a (compound, mixture).
14. Water (H2O) is a (compound, solution)
(page 15)
Directions: Use your textbook to answer each question.
1. Almost every type of matter is a substance or a mixture. Classify elements and compounds
as substances or mixtures. Explain your classification.
Elements and compounds are classified as substances because their composition is always the
same. An element is not a mixture because it contains only one type of atom. A compound is
not a mixture because its elements are chemically bonded.
2. Mixtures can be classified as heterogeneous or homogeneous. Describe the characteristics
of heterogeneous mixtures.
A mixture is two or more substances that are physically blended but not chemically bonded. A
heterogeneous mixture is one in which substances are not evenly mixed.
3. Homogenous mixtures are also known as solutions. Describe the characteristics of
homogeneous mixtures.
Homogeneous mixtures have two or more substances that are evenly mixed on an atomic level
but are not chemically bonded.
4. Although homogeneous mixtures and heterogeneous mixtures share some characteristics,
they are not the same. Identify one way that heterogeneous mixtures and homogeneous
mixtures are different.
Possible answers: The components of a heterogeneous mixture are not evenly mixed, but the
components of a homogeneous mixture are. The parts of a heterogeneous mixture can often be
seen with the unaided eye. The parts of a homogeneous mixture often cannot be seen even
under a microscope.
5. Compounds and mixtures are similar in that both contain more than one kind of matter.
Identify two ways that compounds and mixtures differ.
Possible answers: The components of a compound are chemically bonded, but the components
of a mixture are not. The parts of a mixture keep some of their properties, but the parts of a
compound do not. The parts of a mixture can be separated by physical means, but the parts of
a compound can only be separated by breaking the chemical bonds between them.
(Page 17)
Directions: On the line before each description, write the letter of the term that matches it
correctly. Each term may be used more than once.
A 1. matter made of two or more atoms A. compound
C 2. blood B. element
D 3. air C. heterogeneous mixture
B 4. an atom of oxygen D. solution
C 5. granite
D 6. salt water
C 7. decayed bits of leaves mixed with sand
D 8. a concentration of carbon dioxide mixed in air
D 9. sugar water
B 10. an atom of boron
B 11. a metal pipe made of only copper
C 12. vinegar and oil dressing
(Page 18)
Directions: Answer each question or respond to each statement on the lines provided.
1. What is a substance?
matter that is always made up of the same combination of atoms
2. What is a mixture?
two or more substances that are physically blended but not chemically bonded together
3. What is a heterogeneous mixture?
a mixture in which substances are not evenly mixed
4. Give three examples of heterogeneous mixtures.
Examples should be substances that are not evenly mixed throughout, such as granite, salad
dressing, or blood.
5. What is a solution?
a mixture in which two or more substances are evenly mixed at the atomic level but not bonded
together
6. What is another name for a solution?
homogeneous mixture
7. Give three examples of solutions.
Examples should be homogeneous mixtures, such as air, salt water, or sugar water.
8. How are heterogeneous mixtures and solutions the same? How are they different?
Heterogeneous mixtures and solutions have two or more substances. Heterogeneous mixtures
are not evenly mixed, but homogeneous mixtures are evenly mixed.
(page 19)
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.
T 1. Mixing is a physical change.
T 2. Substances that existed before mixing still exist after substances are mixed.
T 3. Properties of substances are observed in a mixture.
F; elements 4. Properties of a compound can be different from the properties of the
mixtures that make up the compound.
F; chemically 5. Substances that make up mixtures are not physically bonded.
F; physically 6. The substances that make up mixtures can be chemically separated.
T 7. The elements that make up compounds only can be separated as the result
of a chemical change.
F; physical 8. The liquid state of water is an example of a chemical property.
F; compound 9. When sodium and chlorine bond, sodium chloride, or table salt, forms. This
is an example of a mixture.
T 10. Chemical change breaks the bonds between elements.
T 11. The physical properties of one substance are different from those of
another substance in mixtures.
(Page 21)
Understanding Safety Masks
People who work around processes in which hazardous gases or tiny airborne particles might
be present often wear safety masks. The gases and particles form a mixture with the air.
Inhaling the gases or particles can cause lung damage. Simple masks, such as those that
people wear when they are sanding, filter out larger particles of dust. However, smaller particles
and gases easily pass through these masks.
Research Safety Masks
Research the various types of filters that better safety masks use to separate hazardous gases
or particles from the air. How do they differ from simple sanding masks? What kinds of masks
do people wear to help slow the spread of airborne diseases? Each of these involves separating
a mixture.
Prepare a visual display or multimedia presentation explaining why these masks are important
in preserving health and how the various types of masks work. Include diagrams of what
happens as polluted air passes through the filters. When you are finished, share what you have
learned with the class.
Research Notes:
Students should describe the effects of breathing hazardous fumes and fine particulates as well
as explaining and illustrating how each type of mask works to filter these substances. For
example, breathing fine particulates such as dust or the product of sanding can cause the
particles to adhere to the walls of the lungs and reduce the ability of the lungs to exchange
oxygen for carbon dioxide. Many chemical vapors can react with moisture in the nose and lungs
to produce acids or other toxic products. Some harmful volatile gases can enter the bloodstream
through the lungs and act as poisons.
Diagrams might show mechanical filters that remove contaminants from air in the following
ways:
• by finely woven filters that trap fine particles. The filters come in different sizes for particles of
different sizes.
• by diffusion, which is a result of gas molecules colliding with very small particles. This delays
the passage of the particles through the filter.
• by using certain resins, waxes, and plastics as coatings on the filter material to attract particles
with an electrostatic charge that holds them on the surface of the filter material;
• by using the particles themselves, after the filter has been used, to act as a filter medium for
other particles. However, the longer a mask is used, the harder it is for air to pass through it.
• Chemical cartridge respirators use a cartridge to remove gases, volatile organic compounds
(VOCs) and other harmful vapors by adsorption, absorption, or a chemical process that changes
the nature of the vapor. Activated charcoal is a common filter for chemicals.
Accept other answers and types of filters that are supported by student research.
(page 23)
Directions: On the line before each question or statement, write the letter of the correct answer.
1. Which item is a mixture?
A. air
B. carbon
C. copper
D. table salt
2. A sample of matter that contains only one kind of atom would be classified as
A. an element.
B. a compound.
C. a homogeneous mixture.
D. a heterogeneous mixture.
3. A substance is matter that is made up of
A. one type of atom.
B. two or more compounds.
C. matter that has changed chemically.
D. the same combination of atoms all the time.
Directions: On each line, write the term from the word bank that correctly completes each
sentence. Not all terms are used.
chemical compound heterogeneous
homogeneous physical solution
4. A mixture results from a physical change, and a compound results from a chemical one.
5. A compound is matter that is made up of atoms of two or more elements that are chemically
bonded together.
6. A homogeneous mixture is another name for a solution.
7. A heterogeneous mixture is one in which substances are not evenly mixed.
