Solution and Answer Guide: Larry Brown & Tom Holme, Chemistry For Engineering Students, 5e 2025,
9780357974803; Chapter 1: Introduction to Chemistry
Solution and Answer Guide
LARRY BROWN & TOM HOLME, CHEMISTRY FOR ENGINEERING STUDENTS, 5E 2025,
9780357974803; CHAPTER 1: INTRODUCTION TO CHEMISTRY
TABLE OF CONTENTS
Critical Materials ...................................................................................................................1
The Study of Chemistry ....................................................................................................... 2
Observations, Models, and Systems ................................................................................... 4
Numbers and Measurements ............................................................................................... 6
Problem Solving in Chemistry and Engineering ................................................................ 11
Touchscreen Technology ....................................................................................................17
Conceptual Problems ..........................................................................................................18
Focus on Problem Solving Exercises ................................................................................ 20
CRITICAL MATERIALS
1.1 Are the elements designated as critical materials all rare? Explain your answer.
Solution:
While some critical materials may be rare, the classification considers factors beyond
just rarity: primarily an element’s importance and the risk associated with its supply.
1.2 In what country is most of the world’s cobalt mined? What events in that country
dramatically affected the price of cobalt?
Solution:
More than 50% of the world’s annual cobalt production originates from the Democratic
Republic of Congo. Historically, political instability in the region significantly impacted
cobalt prices. Political unrest in the early 1980s caused cobalt price spikes of up to
600%.
1.3 In what types of technology do the elements designated as critical materials generally
play important roles?
Solution:
They are important in batteries, magnetism, and a variety of applications associated
with clean energy and electronics.
© 2025 Cengage Learning, Inc. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly 1
accessible website, in whole or in part.
, Solution and Answer Guide: Larry Brown & Tom Holme, Chemistry For Engineering Students, 5e 2025,
9780357974803; Chapter 1: Introduction to Chemistry
1.4 Based on the information in Figure 1.1, which three elements would you argue are the
most critical among the “critical materials”? Justify your answer.
Solution:
Dysprosium, iridium, and neodynium. These elements rank the highest in supply risk
and are high in importance to energy. Although lithium, nickel, and cobalt rank higher
in importance, they rank lower in supply risk.
1.5 In what region of the periodic table are most of the elements that are listed as critical
materials found?
Solution:
Most of the critical elements are located in the middle of the periodic table,
specifically the region known as the lanthanide series and to a lesser extent the
transition elements.
1.6 What agency of the U.S. government is responsible for identifying an element as a
critical material? What sorts of applications are the primary concern of this agency?
Solution:
The Department of Energy (DOE). Primary concerns are energy-related technologies,
especially clean energy applications such as wind and solar energy and electric cars.
THE STUDY OF CHEMISTRY
1.7 When making observations in the laboratory, which perspective of chemistry are we
normally using?
Solution:
We make observations in the laboratory using the macroscopic perspective of
chemistry, unless very sophisticated instruments are used.
1.8 Which of the following items are matter and which are not? (a) a flashlight,
(b) sunlight, (c) an echo, (d) air at sea level, (e) air at the top of Mount Everest
Solution:
(a) matter, (b) not matter, (c) not matter, (d) matter, (e) matter
1.9 Which macroscopic characteristics differentiate solids, liquids, and gases? (List as
many as possible.)
Solution:
Shape and Volume:
Solids: Solids retain their own shape and volume, resisting deformation. Even when
placed in a container, a solid maintains its shape rather than taking the shape of the
container.
Liquids: Liquids take the shape of their container but maintain a relatively constant
volume.
Gases: Gases expand to fill the entire volume of their container, meaning they do not
maintain a fixed shape or volume.
© 2025 Cengage Learning, Inc. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly 2
accessible website, in whole or in part.
, Solution and Answer Guide: Larry Brown & Tom Holme, Chemistry For Engineering Students, 5e 2025,
9780357974803; Chapter 1: Introduction to Chemistry
Compressibility:
Solids: Solids are generally incompressible, meaning their volume changes very little
under pressure.
Liquids: Liquids are also generally considered incompressible, although they can be
slightly compressed under very high pressure.
Gases: Gases are highly compressible. Their volume can be significantly reduced under
pressure.
Flow:
Solids: Solids do not flow. They resist deformation and maintain a fixed shape.
Liquids: Liquids flow readily and take the shape of their container.
Gases: Gases flow readily and expand to fill any space they occupy.
1.10 Do the terms element and atom mean the same thing? If not, how do they differ?
Solution:
No. An element is a pure substance, but the naturally occurring form of the element
may contain more than one atom. An example of this is elemental nitrogen (N2). In this
case the element has two atoms.
1.11 Label each of the following as either a physical process or a chemical process: (a)
rusting of an iron bridge, (b) melting of ice, (c) burning of a wooden stick, (d) digestion
of a baked potato, (e) dissolving of sugar in water.
Solution:
A chemical change involves a change in the composition of matter; that is, some new
substances are formed. A physical change only involves a change
in the physical state of matter; no new substances are formed.
(a) rusting of an iron bridge Chemical, rust forms when iron and oxygen
react chemically.
(b) melting of ice Physical, change from the solid to the liquid
state.
(c) burning of a wooden stick Chemical, the carbon, oxygen and hydrogen
in the wood are transformed into carbon
dioxide and water during combustion.
(d) digestion of a baked potato Chemical, digestion breaks down larger
complex carbohydrate molecules into
simple molecules (like sugars) through
chemical reactions involving enzymes.
(e) dissolving of sugar in water Physical, the sugar molecules are not
changed, they just become surrounded by
water molecules in solution.
© 2025 Cengage Learning, Inc. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly 3
accessible website, in whole or in part.
, Solution and Answer Guide: Larry Brown & Tom Holme, Chemistry For Engineering Students, 5e 2025,
9780357974803; Chapter 1: Introduction to Chemistry
1.12 Why do physical properties play a role in chemistry if they do not involve any chemical
changes?
Solution:
While physical properties do not involve changes in the chemical composition of
substances, they are essential to understanding and predicting how substances behave
in chemical contexts.
1.13 Physical properties may change because of a chemical change. For example, the color
of an egg “white” changes from clear to white because of a chemical change when it is
cooked. What is another common situation in which a chemical change also leads to a
physical change?
Solution:
The “rusting” of iron is a chemical change. A chemical reaction changes the metal to a
new compound. The rust formed is a brittle, orange-red compound with very different
properties than iron.
1.14 Which part of the description of a compound or element refers to its physical
properties and which to its chemical properties?
(a) Calcium carbonate is a white solid with a density of 2.71 g/cm3. It reacts readily
with an acid to produce gaseous carbon dioxide.
(b) Gray powdered zinc metal reacts with purple iodine to give a white compound.
Solution:
(a) The first sentence describes physical properties; the second sentence describes a
chemical property.
(b) The sentence generally describes a chemical property; however, the stated colors
are physical properties.
OBSERVATIONS, MODELS, AND SYSTEMS
1.15 We used the example of attendance at a football game to emphasize the nature of
observations. Describe another example where deciding how to “count” subjects of
interest could affect the observation.
Solution:
The number of cities located in a state depends on how a city is defined. We would
need to specify what population size makes a city. Our results would vary depending
on that size.
1.16 Complete the following statement: Data that have a small random error but otherwise
fall in a narrow range are (a) accurate, (b) precise, or (c) neither.
Solution:
These data could be precise but not necessarily accurate.
1.17 Complete the following statement: Data that have a large systematic error are (a)
accurate, (b) precise, (c) neither.
© 2025 Cengage Learning, Inc. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly 4
accessible website, in whole or in part.
9780357974803; Chapter 1: Introduction to Chemistry
Solution and Answer Guide
LARRY BROWN & TOM HOLME, CHEMISTRY FOR ENGINEERING STUDENTS, 5E 2025,
9780357974803; CHAPTER 1: INTRODUCTION TO CHEMISTRY
TABLE OF CONTENTS
Critical Materials ...................................................................................................................1
The Study of Chemistry ....................................................................................................... 2
Observations, Models, and Systems ................................................................................... 4
Numbers and Measurements ............................................................................................... 6
Problem Solving in Chemistry and Engineering ................................................................ 11
Touchscreen Technology ....................................................................................................17
Conceptual Problems ..........................................................................................................18
Focus on Problem Solving Exercises ................................................................................ 20
CRITICAL MATERIALS
1.1 Are the elements designated as critical materials all rare? Explain your answer.
Solution:
While some critical materials may be rare, the classification considers factors beyond
just rarity: primarily an element’s importance and the risk associated with its supply.
1.2 In what country is most of the world’s cobalt mined? What events in that country
dramatically affected the price of cobalt?
Solution:
More than 50% of the world’s annual cobalt production originates from the Democratic
Republic of Congo. Historically, political instability in the region significantly impacted
cobalt prices. Political unrest in the early 1980s caused cobalt price spikes of up to
600%.
1.3 In what types of technology do the elements designated as critical materials generally
play important roles?
Solution:
They are important in batteries, magnetism, and a variety of applications associated
with clean energy and electronics.
© 2025 Cengage Learning, Inc. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly 1
accessible website, in whole or in part.
, Solution and Answer Guide: Larry Brown & Tom Holme, Chemistry For Engineering Students, 5e 2025,
9780357974803; Chapter 1: Introduction to Chemistry
1.4 Based on the information in Figure 1.1, which three elements would you argue are the
most critical among the “critical materials”? Justify your answer.
Solution:
Dysprosium, iridium, and neodynium. These elements rank the highest in supply risk
and are high in importance to energy. Although lithium, nickel, and cobalt rank higher
in importance, they rank lower in supply risk.
1.5 In what region of the periodic table are most of the elements that are listed as critical
materials found?
Solution:
Most of the critical elements are located in the middle of the periodic table,
specifically the region known as the lanthanide series and to a lesser extent the
transition elements.
1.6 What agency of the U.S. government is responsible for identifying an element as a
critical material? What sorts of applications are the primary concern of this agency?
Solution:
The Department of Energy (DOE). Primary concerns are energy-related technologies,
especially clean energy applications such as wind and solar energy and electric cars.
THE STUDY OF CHEMISTRY
1.7 When making observations in the laboratory, which perspective of chemistry are we
normally using?
Solution:
We make observations in the laboratory using the macroscopic perspective of
chemistry, unless very sophisticated instruments are used.
1.8 Which of the following items are matter and which are not? (a) a flashlight,
(b) sunlight, (c) an echo, (d) air at sea level, (e) air at the top of Mount Everest
Solution:
(a) matter, (b) not matter, (c) not matter, (d) matter, (e) matter
1.9 Which macroscopic characteristics differentiate solids, liquids, and gases? (List as
many as possible.)
Solution:
Shape and Volume:
Solids: Solids retain their own shape and volume, resisting deformation. Even when
placed in a container, a solid maintains its shape rather than taking the shape of the
container.
Liquids: Liquids take the shape of their container but maintain a relatively constant
volume.
Gases: Gases expand to fill the entire volume of their container, meaning they do not
maintain a fixed shape or volume.
© 2025 Cengage Learning, Inc. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly 2
accessible website, in whole or in part.
, Solution and Answer Guide: Larry Brown & Tom Holme, Chemistry For Engineering Students, 5e 2025,
9780357974803; Chapter 1: Introduction to Chemistry
Compressibility:
Solids: Solids are generally incompressible, meaning their volume changes very little
under pressure.
Liquids: Liquids are also generally considered incompressible, although they can be
slightly compressed under very high pressure.
Gases: Gases are highly compressible. Their volume can be significantly reduced under
pressure.
Flow:
Solids: Solids do not flow. They resist deformation and maintain a fixed shape.
Liquids: Liquids flow readily and take the shape of their container.
Gases: Gases flow readily and expand to fill any space they occupy.
1.10 Do the terms element and atom mean the same thing? If not, how do they differ?
Solution:
No. An element is a pure substance, but the naturally occurring form of the element
may contain more than one atom. An example of this is elemental nitrogen (N2). In this
case the element has two atoms.
1.11 Label each of the following as either a physical process or a chemical process: (a)
rusting of an iron bridge, (b) melting of ice, (c) burning of a wooden stick, (d) digestion
of a baked potato, (e) dissolving of sugar in water.
Solution:
A chemical change involves a change in the composition of matter; that is, some new
substances are formed. A physical change only involves a change
in the physical state of matter; no new substances are formed.
(a) rusting of an iron bridge Chemical, rust forms when iron and oxygen
react chemically.
(b) melting of ice Physical, change from the solid to the liquid
state.
(c) burning of a wooden stick Chemical, the carbon, oxygen and hydrogen
in the wood are transformed into carbon
dioxide and water during combustion.
(d) digestion of a baked potato Chemical, digestion breaks down larger
complex carbohydrate molecules into
simple molecules (like sugars) through
chemical reactions involving enzymes.
(e) dissolving of sugar in water Physical, the sugar molecules are not
changed, they just become surrounded by
water molecules in solution.
© 2025 Cengage Learning, Inc. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly 3
accessible website, in whole or in part.
, Solution and Answer Guide: Larry Brown & Tom Holme, Chemistry For Engineering Students, 5e 2025,
9780357974803; Chapter 1: Introduction to Chemistry
1.12 Why do physical properties play a role in chemistry if they do not involve any chemical
changes?
Solution:
While physical properties do not involve changes in the chemical composition of
substances, they are essential to understanding and predicting how substances behave
in chemical contexts.
1.13 Physical properties may change because of a chemical change. For example, the color
of an egg “white” changes from clear to white because of a chemical change when it is
cooked. What is another common situation in which a chemical change also leads to a
physical change?
Solution:
The “rusting” of iron is a chemical change. A chemical reaction changes the metal to a
new compound. The rust formed is a brittle, orange-red compound with very different
properties than iron.
1.14 Which part of the description of a compound or element refers to its physical
properties and which to its chemical properties?
(a) Calcium carbonate is a white solid with a density of 2.71 g/cm3. It reacts readily
with an acid to produce gaseous carbon dioxide.
(b) Gray powdered zinc metal reacts with purple iodine to give a white compound.
Solution:
(a) The first sentence describes physical properties; the second sentence describes a
chemical property.
(b) The sentence generally describes a chemical property; however, the stated colors
are physical properties.
OBSERVATIONS, MODELS, AND SYSTEMS
1.15 We used the example of attendance at a football game to emphasize the nature of
observations. Describe another example where deciding how to “count” subjects of
interest could affect the observation.
Solution:
The number of cities located in a state depends on how a city is defined. We would
need to specify what population size makes a city. Our results would vary depending
on that size.
1.16 Complete the following statement: Data that have a small random error but otherwise
fall in a narrow range are (a) accurate, (b) precise, or (c) neither.
Solution:
These data could be precise but not necessarily accurate.
1.17 Complete the following statement: Data that have a large systematic error are (a)
accurate, (b) precise, (c) neither.
© 2025 Cengage Learning, Inc. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly 4
accessible website, in whole or in part.
