IPC
Chapter 1
The Nature of Science
IPC Chapter 1 Vocabulary
 bias
 constant
 control
 density
 dependent
variable
 experiment
 hypothesis
 independent
variable
 mass
 matter
 model
 scientific law
 scientific
methods
 SI
 society
 standard
 technology
 theory
 variable
 volume
CHAPTER 1
The Nature of Science
What You’ll Learn
• how scientists solve problems
• why scientists use variables
• how to compare and contrast
science laws and theory
1 The Methods of Science
1(A), 1(B), 2(A), 2(B), 2(C), 2(D), 2(E), 3(A), 3(C)
Before You Read
When you hear the word scientist, what comes to mind?
Brainstorm some words that describe a scientist. Write them on
the lines below.
Focus
Read to Learn
Highlight each heading that is a
question. Use a different color of
marker to highlight the answers
to the questions.
What is science?
Science
Technolog
y
What are the major categories of science?
Science covers many different topics. Life science is the study of
living things. Earth science is the study of Earth and space.
Physical science is the study of matter and energy. In this book,
you will study mainly physical science. You will also learn how
these three main categories sometimes overlap.
How does science change over time?
Scientific explanations help explain the natural world. Scientists
investigate and use technology to get new information.
Sometimes, this new information causes scientific explanations to
change. The model of the atom has changed over time. Scientists
once thought an atom was the smallest particle. We now know
that atoms are made up of protons and neutrons surrounded by a
cloud of electrons. Because science changes, scientists still study
the atom today.
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2
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Understand Main Ideas
Make the following Foldable
to help you organize your
notes about Science and
Technology. Fill it in as you
read the chapter.
Science is not just a subject in school. Science is a way of
studying the world. The word science comes from a Latin work
that means “knowledge.” Science is a way to learn or gain
knowledge by observing and investigating.
Scientific inquiry is a process for asking questions and
investigating the world. Science uses scientific inquiry to form
explanations that can be tested. Those explanations can also be
used to make predictions about the world.
Scientific Methods
A scientific method is a set of steps used in an investigation.
Scientists follow steps similiar to those listed below when doing
an investigation. These steps guide the scientist. Some steps may
be repeated. Other steps may be skipped. The flowchart below
shows six common steps found in various scientific methods.
Think it Over
State the problem.
1. Draw Conclusions Why
might steps in scientific
methods be skipped or
changed?
Gather information.
Modify the
hypothesis.
Form a hypothesis.
Test the hypothesis.
Repeat
several
times.
2. Interpret Why are there two
arrows leading to different
parts of the chart at the
bottom?
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Analyze data.
Draw conclusions.
Hypothesis is
not supported.
Take a Look
Hypothesis is
supported.
Stating a Problem Many scientific investigations begin with a
question about how or why something happens in nature. The
problem is stated as a “how” or “why” question.
Scientists once asked why objects fall to Earth, what causes day
or night, or how electricity can be generated. Some of the answers
to these questions lead to more questions. For example, once
scientists knew what caused day and night, they wanted to know
why Earth rotates.
Scientists might want to solve a particular problem. For
example, NASA scientists needed to find a way to protect the
instruments and crew onboard the space shuttle.
Reading Essentials • The Nature of Science
3
Think it Over
3. Research List two places
where you might find
information on the
development of the space
shuttle.
Researching and Gathering Information It is important to
study a problem before any testing is done. Sometimes someone
has already solved a similar problem. NASA scientists gathered
information about melting points and other properties of various
materials that might be used. They also performed tests on newly
created materials.
Forming a Hypothesis A hypothesis is a possible explanation
for a question or problem based on what you know and what you
observe. A scientist who forms a hypothesis must be certain it can
be tested. NASA scientists knew that a certain ceramic material
had been used to protect the nose cones of guided missiles.
They hypothesized that a ceramic material might also protect
the space shuttle.
Testing a Hypothesis Some hypotheses are simply tested by
making observations. Building a model may be the best way to
test a hypothesis. Scientists may also use an experiment to test a
hypothesis. The experiment looks at how one thing affects
another under controlled conditions. NASA scientists built model
space shuttles and covered them with various materials. They
tested the models in simulated re-entry environments to see
which material gave the best protection.
Think it Over
Types of Variables
Dependent
Variable
changes according to the changes of the
independent variable
Independent
Variable
the variable that is changed to test the effect on
the dependent variable
Constant
a factor that does not change when other
variables change
Control
the standard by which the test results can be
compared
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4
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4. Define What are the two
kinds of variables that are
tested in experiments?
Variable An experiment usually has at least two variables.
A variable is a factor that can cause a change in the results of an
experiment. Suppose you set up an experiment to see which
fertilizer makes plants grow biggest. First, you need to think of all
the factors that can make a plant grow bigger. These might
include the type of plant, amount of sunlight, amount of water,
type of soil, and amount of fertilizer.
In this experiment, the amount of growth is one variable. It is a
dependent variable because its value changes according to the
changes in other variables. The other variable is the amount of
fertilizer. The independent variable is changed to see how it
affects the dependent variable.
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Constants and Controls To keep an investigation fair, all other
factors must be the same. A constant is a factor in an experiment
that does not change. In the fertilizer experiment, the constants
are the amount of water and sunlight the plants get and the
temperature at which the plants are kept. These are the same for
all plants tested. Three plants get different amounts of fertilizer,
which is the independent variable.
A control is used to compare the results of the experiment.
One plant is a control and does not get any fertilizer, but does get
the same sunlight, water, and temperature as the other plants.
Suppose after several days that the control plants grow between
2 and 3 cm. If the unfertilized plant grows only 1.5 cm, you might
infer that the greater growth of the fertilized plants was caused by
the fertilizer.
Analyze the Data An important part of any experiment is
recording observations and organizing information. All results
and observations should be recorded during an experiment.
Many important discoveries have been made from unexpected
results. The information or data should be organized into an
easy-to-read table or graph. Later in this chapter, you will learn
how to show your data.
Understanding what the data and observations mean is also
important. The data must be organized logically. Poorly organized
data may lead to a wrong conclusion. Scientists share their data
through reports and meetings. Scientists may disagree about
certain data, no matter how well the data is presented.
Drawing Conclusions Scientists look at their data and decide if
the data support the hypothesis. If the data is the same after many
experiments, the hypothesis is supported. If the hypothesis isn’t
supported, scientists may change it or the experiment.
Sometimes others don’t agree with the conclusions, so they
design new experiments to test the hypothesis. In time, data will
support a valid hypothesis.
Being Objective Scientists must avoid a bias. A bias occurs
in an experiment when a scientist expects something to happen
and lets this influence how the results are viewed. Scientists try
to reduce bias whenever they can by doing the experiment many
times and keeping careful notes about observations. Also, other
scientists repeat the same experiment to see if they get the
same results.
Reading Essentials • The Nature of Science
5
GET IT?
5. Identify What is the purpose
of a control in an experiment?
Think it Over
6. List two reasons why data
must be organized.
GET IT?
7. Explain why a scientist must
be unbiased.
Think it Over
8. Classify Give an examples of
qualitative and quantitative
data.
Student-Driven Scientific Inquiry
You will conduct investigations and experiments as you learn
science. Some lab assignments include a series of steps to follow.
Other investigations will be designed by you. When you plan an
investigation, you should choose the appropriate equipment and
supplies.
How is data collected?
When you perform an investigation, you will gather
data—information gained from observations. The data might be
qualitative or quantitative data. Qualitative data are descriptions
of what we see, hear, feel, and smell. Quantitative data contain
numbers. Quantitative data come from taking careful
measurements.
Accuracy and Precision You will often collect data several
times in one investigation. If your measurements are close to one
another, they are considered to be precise. If your measurements
are close to a real or accepted value, they are considered to be
accurate. By practicing your skills in the lab, you can make
accurate and precise measurements.
How should resources be used?
In the lab, it is important to conserve resources. Choose
reusable supplies whenever possible. Take only enough material
to complete your investigation. And when an investigation is
finished, follow your teacher’s instructions to dispose of materials.
Recycle materials whenever possible to reduce waste and reduce
the amount of resources used.
Applying Math
9. Calculate how many cups
would be used in the school
had 450 students doing the
lab working in teams of three.
Using Reusable Equipment Using disposable supplies might
sound convenient, but it creates trash. Instead, try to use materials
that can be reused. For example, use washable glassware instead
of plastic cups.
Consider a school that has 200 students in 10 classes all doing
the same lab. If each two-person lab team used one disposable
cup, that’s 100 cups that get thrown away. If they had used beakers
instead, there would be much less trash. Recycling materials
conserves many kinds of resources.
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Organizing Data When working in the lab, it is important to
stay organized. Many scientists use notebooks to record
observations. Data tables are used to record data. Some
investigations take several days. Using a notebook keeps data
together and keeps information from getting lost.
Using Small Amounts When conducting an investigation, the
smallest amount of all resources should be used. This is especially
true when doing chemistry experiments. Chemicals can be costly.
In addition, disposing of chemicals can be costly and difficult.
Disposing of Waste Responsibly Even when you use reusable
materials and only a small amount of supplies, there is still waste.
Properly disposing of waste is important. Laboratory waste can
harm environments and pollute air, land, and water. Local
governments often have rules for waste disposal. Following
guidelines for waste disposal helps to reduce pollution.
How are laboratory investigations conducted safely?
When you conduct lab procedures, you will be warned of safety
hazards. Some labs have special warnings. Others use safety
symbols. A safety symbol is a logo designed to alert you to a
specific danger. The table below lists common safety symbols
found in physical science labs.
Think it Over
10. Explain why using small
quantities is important.
Take a Look
11. Compare What is the
difference between the
symbol with the flames and
the one with flames behind
a “no” symbol?
Laboratory Safety Symbols
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Symbol
Hazard
Precaution
Special disposal procedures need to be
followed.
Follow your teacher’s instructions.
Objects that can burn skin by being too
hot or too cold
Use proper protection or equipment when handing.
Use of tools or glassware that can easily
slice or puncture skin
Practice common-sense behavior and follow
guidelines for use of the tool.
Possible danger to respiratory tract from
fumes
Work where there is good ventilation. Wear a mask.
Never smell fumes.
Possible danger from electrical shock or
burn
Double-check setup with teacher. Check condition
of wires and apparatus.
Substances that can irritate the skin or
respiratory tract
Wear dust mask and gloves. Practice extra care
when handling materials.
Chemicals that can react with and
destroy tissue
Wear goggles, gloves, and an apron.
Open flame may ignite flammable
chemicals, loose clothing, or hair.
Avoid open flames and heat when using flammable
chemicals.
Open flame in use; may cause fire.
Tie back hair and loose clothing. Follow teacher’s
instructions on lighting and extinguishing flames.
Reading Essentials • The Nature of Science
7
Think it Over
12. Explain What information
should be found on a
chemical’s MSDS?
Completing Lab Safety Forms Before working in the lab, read
the entire procedure carefully. Take note of safety symbols and
warnings. Fill-out a lab safety form and have it approved by your
teacher. If there are any accidents while you are in the lab, contact
your teacher immediately.
Understanding the MSDS Chemical manufacturers produce
information about the chemicals they produce. This information
includes safety hazards, special first-aid procedures, and chemical
storage instructions. The information is on a Material Safety Data
Sheet (MSDS). The MSDS for each chemical used in the lab
should be kept near the chemicals. Before conducting an
investigation that uses chemicals, find and read the MSDS for
each chemical.
Evaluating Scientific Explanations
Think it Over
How do you evaluate published scientific information?
When you read about new scientific discoveries or
explanations, you should ask yourself “How were these
conclusions reached?” Can you find the empirical evidence used
to come to the conclusion? See if you can understand the logical
reasoning used to draw conclusions.
When scientists publish their findings, they explain their
methods. They may use experimental testing in controlled
investigations. Or they may use observational testing, gathering
data from observations. When evaluating scientists’ findings, be
sure to examine all sides of scientific evidence. Watch out for
unsupported conclusions or bias.
Reading Essentials • The Nature of Science
8
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13. Infer Why would a scientist
include their methods when
they publish their findings?
Scientists analyze and evaluate scientific explanations. Recall
that science is always changing. It grows and changes because of
new discoveries and technology. Scientists sometimes disagree.
This can lead to new research and discoveries.
How do you make informed decisions about science? You must
analyze, evaluate, and critique scientific explanations.
• Analyze—break down the scientific explanation into parts
• Evaluate—study closely the scientific explanation; consider
what you already know; look at the scientific methods used to
support the explanation
• Critique—review and consider the merits and faults of the
explanation and its parts
How do you evaluate promotional materials?
When you read advertisements for products and services you
might see scientific claims. Use the same skills you would use
when you read scientific information. First, analyze the claims in
the promotional materials. What are the specific claims they
make? Then, evaluate the scientific claims. What evidence is
presented? Do they reference scientific investigations? Where
does their evidence come from? Finally, critique the claims. Do
the claims make sense? Or do they seem biased? Or false? Often,
logical reasoning and your life experiences are all you need to
evaluate promotional materials.
Visualizing with Models
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Sometimes, scientists cannot see everything they are testing.
They might be studying something too large or too small to see.
It might even take too much time to see completely. In these
cases, scientists use models. A model represents an idea, event, or
object to help people better understand it. A model may be a
physical object such as a scaled-down version of the space shuttle.
A model can also be represented by a drawing on paper or by a
computer program.
Models in History Models have been used throughout history.
Lord Kelvin, a scientist who lived in England in the 1800s, was
famous for making models. To model his idea of how light moves
through space, he put balls in a bowl of jelly. He asked people to
move the balls with their hands. Kelvin’s work explaining heat and
temperature is still used today.
Think it Over
14. Explain What are models?
What are high-tech models?
Scientific models don’t have to be something you can touch.
Many scientists use computers to build models. Computer models
are used to solve difficult mathematical equations. NASA uses
computers in experiments with space flights to solve equations
that are too hard or would take too long to solve by hand.
Another type of model is a simulator. A simulator can create
the conditions found in real life. For example, a flight simulator is
a model of an airplane. It can help a pilot pretend to be flying a
plane. The pilot can test different ways to solve problems. The
simulator reacts the same way a real plane does when it flies, but
there is no danger to either the pilot or a plane.
Reading Essentials • The Nature of Science
9
Think it Over
15. List three differences
between a flight simulator
and a real airplane.
Scientific Theories and Laws
Think it Over
16. Restate What is a scientific
law?
A scientific theory is a way of explaining things or events based
on what has been learned from many observations and
investigations. When these observations and investigations have
been repeated many times and support the hypothesis, then the
hypothesis becomes a theory. New information in the future may
change the theory.
A scientific law is a statement about what happens in nature
and seems to be true all the time. A law explains what will happen
under certain conditions, but it does not explain why or how it
happens. Theories are used to explain how and why laws work.
Gravity is an example of a scientific law. The law of gravity says
that any one mass will attract another mass. To date, no
experiments have been done that prove this law is not true.
The Limitations of Science
Science is used to explain many things about the world.
However, science cannot explain everything. Questions about
emotions or values are not questions science can answer. A survey
of peoples’ opinions would not prove that these opinions are true
for everyone. Scientists make predictions when they perform
experiments. Then these predictions are tested and verified by
using a scientific method.
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Reading Essentials • The Nature of Science
10
What You’ll Learn
• the SI units and symbols for
length, volume, mass, density,
time, and temperature
2 Standards of Measurement
1(A), 2(D), 2(C), 2(E)
Before You Read
• how to convert related SI units
If someone asked you how wide your desk is, how would you
measure it? Would you measure using inches, centimeters, feet,
yards, or meters? Write why you selected this unit of measure.
Focus
Read to Learn
Make an outline of the
information in this section. Use
each of the headings as part of
the outline.
Units and Standards
Measurement Systems
Suppose the label on a ball of string says that the length of the
string is 1. Is the length 1 meter (m), 1 foot (ft), or 1 centimeter
(cm)? How do you know? For a measurement to make sense, it
must include a number and a unit.
You might buy lumber by the foot, milk by the gallon, and
potatoes by the pound. These units are part of the English
system of measurement. The English system is commonly used
in the United States. Most other nations use the metric system.
The metric system is a measurement system based on multiples
of ten.
Reading Essentials • The Nature of Science
12
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A standard is an exact quantity that people agree to use to
compare measurements. A standard is always exactly the same
quantity when it is used anywhere in the world. Without
standards, it is difficult to compare things that can be measured.
Suppose you and a friend want to measure your desk but do not
have a ruler. Instead, you use your hands as tools to measure the
desk. If you each measure the desk using your own hands, will
you both get the same measure? You can’t be sure, because you
don’t know if your hands are the same size.
International System of Units
In 1960, an improvement was made to the metric system. This
improvement is known as the International System of Units. This
system is often abbreviated SI from the French Le Systeme
Internationale d’Unites. The SI standards are accepted and used by
scientists all over the world. Each type of SI measurement has a
base unit. The base unit for length is the meter. The names and
symbols for the seven base units are in the table below. All other
SI units come from these seven base units.
Take a Look
SI Base Units
Quantity Measured
Unit
Symbol
Length
meter
m
Mass
Kilogram
Kg
Time
second
s
Electric current
ampere
A
Temperature
Kelvin
K
Amount of substance
mole
mol
Intensity of light
candela
cd
1. Recognize Circle the base
units that you have seen
before.
GET IT?
2. Calculate How many meters
is in 1 km? How many grams
is 1 dg?
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What are SI prefixes?
The SI system is easy to use because it is based on multiples
of ten. A prefix is added to the name of the base unit to indicate
how many multiples of ten it should include. For example, the
prefix kilo- means 1,000. That means that one kilometer is
equal to 1,000 meters. This also means that one kilogram equals
1,000 grams. The most commonly used prefixes are shown in the
table below.
Common SI Prefixes
Prefix
Symbol
Multiplying Factor
Kilo-
K
deco-
d
0.1
centi-
c
0.01
milli-
m
0.001
micro-
μ
0.000 001
nano-
n
0.000 000 001
1,000
Reading Essentials • The Nature of Science
13
Take a Look
3. Identify Which of the
following is the smallest?
(Circle your choice.)
a. decigram
b. nanogram
c. milligram
d. kilogram
How do you convert between SI units?
Sometimes quantities are measured using different units.
Suppose a teacher has 1.3 L of water for a class experiment. She
needs 125 mL to conduct the experiment. To determine if she
has enough water, she must first find out how many mL of water
she has.
Apply Math
4. Convert Units A length of
rope measures 3,000
millimeters. How long is it in
meters?
1m
3,000 mm × _
1,000 mm
3,000
1m
_×_
1
1,000
3,000 m
_
=
1,000
Conversion Factors A conversion factor is used to change
measurements from one unit to another. A conversion factor is a
ratio that equals one. For a ratio to equal one, the numerator and
denominator must have the same value. The numerator of a
conversion factor should be the new unit. The denominator
should be the old unit. For example, if you are converting liters to
milliliters, use the following conversion factor.
new unit _
_
= 1000 mL
1L
old unit
To find out how much water she has in mL, the teacher
multiplies the amount of water she has by the conversion factor.
1000 mL
1.3 L × _
1L
1000 mL
1.3 L × _
1L
1.3 × 1000 mL = 1,300 mL
Measuring Distance
In science, the word length is used to describe the distance
between two points. The SI base unit of length is the meter, m.
A baseball bat is about 1 m long. Metric rulers and metersticks
are commonly used to measure length. A meter is slightly longer
than 1 yard, as shown by the meter-stick and the yardstick in the
figure below.
Take a Look
5. Circle Circle the length by
which the meterstick is
longer than the yardstick.
Yard
2
3
4
5
6 7
5
13
4
3
2
1
8
9
10
6
7
8
19
17 18
15 16
13 14
11 12
9
14
10
11
12
14
29
27 28
25 26
23 24
20 21 22
13
30 31
14
38
15
16
38 39
36 37
34 35
32 33
17
40 41
18
12
19
48
46 47
44 45
42 43
20
51
49 50
Reading Essentials • The Nature of Science
14
21
22
23
58
25
24
58 59
56 57
54 55
52 53
60 61
26
27
34
28
68 69
66 67
64 65
62 63
Meter
70
29
30
31
32
78
79
77 78
75 76
73 74
71 72
80 81
33
34
35
88 89
86 87
84 85
82 83
90 91
98
96 97
94 95
92 93
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The teacher has 1,300 mL of water. That is enough for her
experiment!
How do you choose a unit of length?
When measuring distance, it is important to choose the proper
unit. The unit you choose will depend on the object being
measured. For example, you would measure the length of a pencil
in centimeters (cm). The length of your classroom would be
measured in meters. The distance from school to your house
would be measured in kilometers (km). By choosing the best unit,
you can avoid very large or very small numbers. It is easier to say
something is 21 km rather than saying it is 21,000 m.
Measuring Volume
Apply Math
Volume is the amount of space an object fills. The volume of
a rectangular solid, such as a brick, is found by multiplying its
length, width, and height (V = l × w × h). If the sides of the
brick were measured in centimeters, cm, the volume would be
expressed in cubic centimeters, cm3. When you multiply all three
measurements, you multiply “cm” three times, once with each
measurement. The result is cm3. If you were trying to find out
how much space there is in a moving van, you would measure
the van using meters. Its volume would be expressed in cubic
meters, m3. Let’s find the volume of this van.
6. Define In the calculations for
finding the volume of the
van, ( m × m × m) is
rewritten as m3. The 3 in m3 is
called an exponent. What
does an exponent represent?
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2m
4m
3m
First find the length, width, and height of the van.
Length = 4 m
Width = 2 m
Height = 3 m
Substitute these values into the formula for finding volume.
V=l×w×h
=4m×2m×3m
= (4 × 2 × 3)(m × m × m)
= 24 m3
The volume of the moving van is 24 m3.
Reading Essentials • The Nature of Science
15
Apply Math
7. Calculate What is the
volume of a brick that has
a length of 20 cm, a width of
6 cm, and a height of 5 cm?
Show your work.
How do you measure the volume of a liquid?
Think it Over
8. Measure What are the most
common units for expressing
the volume of liquids?
Measuring the volume of a liquid in a container is different
from measuring a solid object because the liquid does not have
sides. To measure the volume of a liquid, you must use a
container with a known capacity. Its measuring units should be
marked. The most common units for expressing the volume of
liquids are liters (L) and milliliters (mL). A milliliter is equal in
volume to 1 cm3. So, the volume of 1 L equals 1,000 cm3. Look at
food cans and bottles to see how these measurements are used.
Measuring Mass and Density
Mass is the measure of how much matter is in an object. Matter
is anything that has mass and takes up space. A golf ball and a
table-tennis ball are about the same size. The golf ball has more
matter and mass, than the table-tennis ball.
What is density?
Apply Math
What are derived units?
The measurement for density, g/cm3, is a combination of SI
units. A unit made by combining different SI units is called a
derived unit. An SI unit multiplied by itself is also called a derived
unit. For example, the liter, which is based on the cubic decimeter,
and a meter cubed, m3, are both derived.
Measuring Time and Temperature
Sometimes scientists need to keep track of how long it takes
something to happen or whether something heats up or cools
down. These are measurements of time and temperature. in the SI
system is the second (s). Seconds are usually measured with a
clock or stopwatch.
Time is the interval between two events. The unit of time in the
SI system is the second (s). Seconds are usually measured with a
clock or stopwatch.
Reading Essentials • The Nature of Science
16
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9. Calculate Suppose an object
weighs 15 g and has a
volume of 5 cm3. What is the
density of the object?
Another property of matter is density. The density of an
object is the amount of mass in one cubic unit of volume of the
object. You can find density by dividing an object’s mass by its
volume. Suppose an object weighs 10 g and has a volume
of 2 cm3. The density of the object is 5 g/cm3.
If two objects are the same size and one object has a greater mass,
it also has a greater density. This is because the more dense object
has more mass in one cubic unit of volume than the other object
has in one cubic unit of volume. The golf ball and the table-tennis
ball have about the same volume. However, the golf ball has a
greater mass. This means that the golf ball also has a greater density.
What’s hot and what’s not?
Sometimes scientists need to measure how much something
heats up or cools down. Temperature is a measure of how much
energy something has. Later, you will learn the scientific meaning
of temperature.
What is Celsius?
Scientists use the Celsius (C) scale to measure temperature.
This scale was designed to show that 0°C is the freezing point of
water, and 100°C is the boiling point of water. The scale is divided
into 100 equal divisions, or degrees, between the freezing point
and the boiling point of water.
What is Fahrenheit?
Copyright © McGraw-Hill Education. Permission is granted to reproduce for classroom use.
The temperature measurement you are probably most familiar
with is the Fahrenheit (F) scale. On this scale, water freezes
at 32°F and boils at 212°F.
What is Kelvin?
Think it Over
The SI unit of temperature is kelvin (K). On the Kelvin scale, 0 K
is called absolute zero. This is the coldest possible temperature.
Absolute zero is equal to –273°C, which is 273° below the freezing
point of water. The divisions on the Kelvin and Celsius scales are
the same size. This makes it easy to convert between the two scales.
Water freezes at 0°C. To convert to Kelvin, you add 273 to the
Celsius temperature. So, water freezes at 273 K. Water boils at
100°C or 373 K.
10. Restate At what
temperature does water
freeze, and at what
temperature does water boil
on the Celsius scale?
K
°C
380
110
373.15
370
100
80
350
70
340
60
330
50
320
40
310
30
300
20
290
10
273.15
270
0
260
-10
20
-250
10
-260
0
100.00
90
360
280
°F
0.00
-270
0.00
-273.15
210
200
190
180
170
160
150
140
130
120
110
100
90
80
70
60
50
40
30
20
10
-420
-430
-440
-450
-460
212.00
Take a Look
32.00
-459.67
Reading Essentials • The Nature of Science
17
11. Label each thermometer in
the diagram with the name
of its temperature scale.
3 Science and Technology
2(D), 3(D)
Before You Read
You use different kinds of technology every day. What do you
think of when you hear the word technology?
What You’ll Learn
• types of technology
• value of technology
• consumer effect on
technology
Incorporate the information
from this section into your
foldable.
Read to Learn
What is technology?
Copyright © McGraw-Hill Education. Permission is granted to reproduce for classroom use.
The terms science and technology mean very different things.
Science is a process of exploration. Scientific processes are used to
gain knowledge of and predict events in the natural world.
Scientists often search for answers to human needs and problems.
Scientists also search for scientific knowledge for the sake of
learning new information.
Technology When scientific knowledge is used to solve a
human need or problem, the result is called technology.
Technology is the use of scientific knowledge of materials and
processes to benefit people. An aspirin pill, a car, and a national
highway system may not seem to have much in common. These
things are all very different, but they are all examples of
technology. Technology can be:
• any human-made object (such as a radio, computer or
hammer),
• methods or techniques for making any object or tool (such as
the method for making glass),
• skills needed to operate a human-made object (such as the
skills needed to drive a car), or
• a system of people and objects used to do a task (such as the
Internet, which is a system to share information).
Reading Essentials • The Nature of Science
19
Science
Technolog
y
Think it Over
1. Define What is technology?
What are technological methods or techniques?
Just as writing instruments have changed over time, so have
methods or techniques for doing many tasks. The methods for
printing books have changed over time. Long ago people had to
copy each page of a book by hand. This took many hours. Books
were expensive, and only the very rich could pay for them. Now,
books are created in many ways. Modern printing presses create
most of the books today. Printing press technology printed your
textbook. Books can be written on computers and are sometimes
printed on computer printers. The printing press and computer
technology save countless hours in producing books.
What are technological knowledge and skills?
Technology is not just new machines and new techniques. It is
also the knowledge and the skills needed to do a task.
For example, you need knowledge and special skills to use most
computers. Any skill used to operate a complex machine is a
technological skill.
GET IT?
2. Identify another example of
a technological system.
Explain why it fits into this
category.
What are technological systems?
Global Technological Needs
You just read how technology has changed over time.
Today, not all parts of the world value the same technologies. The
technology valued in the United States may not be valued in other
parts of the world. Industrialized nations have different
technology needs than developing nations.
Reading Essentials • The Nature of Science
20
Copyright © McGraw-Hill Education. Permission is granted to reproduce for classroom use.
A network of people and objects working together to do a job
also is technology. The network is technology, the objects are
technology, and the skills of the people are technology.
The Internet is a good example of this kind of technology. The
Internet is a collection of computers and software that people
with skills use to send and receive information. The airline
industry is another example of a technological system. This
industry is a collection of objects, methods, systems, and rules.
An airport’s planes, pilots, and computers create a technology
system that moves people and goods.
What are the needs of developing countries?
In some parts of the world, people work hard for basic needs
such as food, shelter, clean water, and basic health care. Consider
a family living in rural Kenya. Most rural Kenyan families live
without electricity or running water in their homes. Droughts or
small amounts of rain can cause food shortages and famine. Rural
Kenyans also have limited health care. Because of limited health
care infections and diseases, such as HIV/AIDS, are severe
problems in many developing nations.
Think it Over
3. Apply Name two
technologies that people in
developing nations could
benefit from.
Meeting Basic Needs Technological solutions in developing
countries are limited to supplying basic needs. Technology that
would supply safe drinking water would be valued before
technology such as access to the Internet. Increasing access to
basic health care would improve the quality of life. Health care
technology would also increase life expectancy in developing
countries.
Within developing countries, not all technologies are valued
the same. The technologies valued by people in rural parts of
developing countries are different than the technology valued by
people living in cities. For example, in a crowded city, technology
for disposing of waste is more valued than farming technology.
Copyright © McGraw-Hill Education. Permission is granted to reproduce for classroom use.
What technology is used in industrialized countries?
The United States is an industrialized country. Because of
technology, industrialized countries have access to safe, clean
water and food supplies. Most homes have running water and
electricity. Good health care is available to treat people. The life
expectancy of Americans is the late-seventies.
People in industrialized nations often value technology that
helps provide a higher quality of life. Most homes in the United
States have computers, telephones, and televisions. The people of
industrialized nations value technologies like faster computers,
compact discs, and safer cars.
Advances in medicine improve people’s lives by curing
illnesses and diseases. Some people spend money on medical
procedures to improve their quality of life. Plastic surgery can
remove wrinkles from a person’s face. Eye surgery can improve a
person’s vision so he or she may not have to wear glasses.
Reading Essentials • The Nature of Science
21
Think it Over
4. Explain What are two
technologies that are valued
in industrialized nations?
How do developing nations contrast?
Both developing and industrialized nations value technology
that helps supply basic human needs: clean water, enough food,
and basic health care. However, the technology for basic needs
may be very different in developing nations. For example, people
in rural areas in some countries could get clean water if handpumps were installed in villages.
GET IT?
5. Compare and contrast the
technological needs of
developing and industrialized
countries.
Social Forces that Shape Technology
Science and society are closely connected. Society is a group of
people that shares similar values and beliefs. Discoveries in
science and technology change society, and likewise society
affects how new technologies develop. The politics, values, and
economics of a society affect what new technologies develop.
How did attitudes toward cars change?
6. Explain How does buying a
certain brand of tablet affect
the development of tablets in
general?
Do consumers affect technology?
If people do not want a technology, they will not buy it.
Companies are not likely to spend additional money to develop
technology that consumers will not buy. On the other hand, if
consumers buy a technology, companies will spend additional
money to improve the technology. For example, if consumers
continue to buy fuel-efficient cars, more money will be spent on
improving that technology.
Reading Essentials • The Nature of Science
22
Copyright © McGraw-Hill Education. Permission is granted to reproduce for classroom use.
Think it Over
An example of the connection between a society’s values and
its technology is the development of the car in the United States.
Over the last 100 years, the people of the United States have
changed their attitudes toward cars.
When they were first invented, cars were expensive. Then
technology was developed to mass-produce affordable cars.
Many people were able to own cars because of the changes in
technology and manufacturing. This increased the demand for
fossil fuels like gasoline. Technology developed that made gas
and oil more accessible and affordable. As more cars were sold,
the demand for gas and oil increased.
Now gas prices are high and oil is becoming scarce, so people
are beginning to buy more fuel-efficient cars. The automobile
industry is responding with new technology, such as hybrid cars
that use both electricity and gasoline.
Do personal values affect technology?
People support new technologies that agree with their personal
needs and values, directly and indirectly. For example, people
support the development of technology indirectly when they
choose to vote for a political candidate. Support for a candidate
translates into support for the projects, technological and
otherwise, that that candidate favors. People support the
development of technology directly when they give money to
organizations committed to a specific project, such as cancer
research.
Economic Forces that Shape Technology
Many factors influence whether money is spent on a
technology, and many questions must be answered before the
money is spent. The questions include who will buy the product,
what the benefits of the technology are, and how much it will cost
to make.
Copyright © McGraw-Hill Education. Permission is granted to reproduce for classroom use.
What is the influence of the federal government?
One way technology research and development is funded is
through the federal government. Every year, Congress and the
president place large amounts of money in the federal budget for
scientific research and development. For example, Congress and
the president decide how much money will be spent on new
technologies in agriculture, defense, energy, and transportation.
The money is given to companies and institutions in the forms of
contracts and grants.
What is the influence of private foundations?
Think it Over
Some scientific and technological research is supported with
money from private foundations. Foundations raise money for
many types of research, such as cancer and muscular dystrophy.
Foundations raise money in many ways, including charity races,
telethons, and benefit concerts. Many private foundations focus
on research for specific scientific issues, such as treatment for
Alzheimer’s disease.
7. Identify three things the
federal government pays to
develop.
What is the influence of private industries?
Private industries also fund research and development of new
technology. Like the federal government, private industries use a
portion of their budget on research and development. Investing in
new technology can make money for the company. Selling the
new products or technologies they develop to consumers is one
way companies make profits.
Reading Essentials • The Nature of Science
23
Think it Over
8. Conclude Why is it
important for humans to
think about the positive and
negative effects when they
create technology?
Moral and Ethical Issues
Humans can invent technology that may have an impact on
other living things. Humans are part of many ecosystems on
Earth, and it is important that new technology does not destroy
the environment. Humans must think of both the positive and
negative effects of their inventions.
How can technology affect the environment?
When the effects of technology are known, the benefits of the
technology often are more important than the negative effects.
For example, gasoline-powered cars give people safe, reliable
transportation. The negative effects are the environmental
problems created by the use of cars.
What are ethical questions related to science?
Think it Over
9. List five examples of
biotechnology.
Ethical issues raise questions of what is right or wrong, what is
fair, or what is in the best interest of society. Ethics help scientists
create guidelines to follow. Scientists follow standards when
collecting, analyzing, or reporting data.
Scientists sometimes study animals as part of scientific
research. Poor treatment of human or animal test subjects in the
past has led to public outcry. Ethical questions about these
practices helped create new laws and guidelines. These new laws
help prevent unethical treatment of humans and animals in
scientific research.
Any technology using living things or living systems is
called biotechnology. Breeding animals for certain traits is
biotechnology. So is baking with yeast or using fermentation to
make cheese or wine. These biotechnologies had been used for
many years.
Today, biotechnology includes research in many areas. Some
scientists are studying genetically-engineered crops. Other
scientists are studying the unique properties of stem cells. Some
of these research areas are controversial. They challenge society’s
values and beliefs. As with all scientific research, biotechnology
must be examined for its impact on individuals, society, and the
environment.
Reading Essentials • The Nature of Science
24
Copyright © McGraw-Hill Education. Permission is granted to reproduce for classroom use.
What is biotechnology?