4 How to Be a Successful Student
to accomplish this is by using your finger to trace under
the words slightly ahead of where you’re reading. Slow
down your pace and reread important ideas, concepts,
and key terms. Highlighting, writing notes in a separate
notebook, and marking up the margin in your textbook
are all excellent ways to make your reading more active.
When you come across an extremely important fact or
concept, grab a brighter-colored pen than the one you
are using, to denote how special that item is. Flag ideas
or key terms that need to be revisited with a unique color
or with sticky notes available at any office supply store.
As you approach a new section, reread the heading
and turn it into a question. For example, when reading
the section titled “Rods and Cones Operate Using Dif-
ferent Chemical Mechanisms,” rephrase it as “How Are
Chemicals Used by Rods and Cones?” By doing this, you
turn your passive reading of material into an active quest
to answer an important question.You and Your Textbook
learning ObjeCtives
- recognize the textbook as a tool.
- identify and define the components of a
textbook.
extbooks are some of the best tools avail-
able to college students. Contained with-
in their pages is a rich presentation of
the fundamentals and examples of your
course’s topic. If used correctly, a text-book can be the
key to academic success.
Although it may be tempting to do so, you should not
read your textbook from beginning to end like the lat-
est best-selling novel. When you read for entertainment,
you’re generally reading in a passive manner. It is far
more productive to be an active reader, which will help
you retain the most information from your study time.
When beginning a new chapter, think about go-
ing from broad to specific. The broadest section of any
chapter is the summary, found at the beginning or at the
end. By reading the summary first, you will get a general
overview of the chapter. In just a few paragraphs, you can
jumpstart your brain and be fully prepared for the content
ahead. Next, go through each page and read just the bold,
italicized, or underlined key ideas, headings, and terms
(Figure 0.1). These first steps should be taken before a
scheduled lecture and when independently working on
your assigned reading. Use your Chapter Planner, found
on the first page of each chapter, as a roadmap. Here,
you can quickly find and check off the most important
elements of the chapter.
Next, take the practice quiz found at the end of the
chapter. It is always acceptable to fail while you’re learn-
ing and practicing. By answering review questions in the
beginning, you can calibrate your attention to what is
important and get a sense of how comfortable you are
with the material. Of course, even if you happen to get a
perfect score, you should not skip reading the chapter.
Once you’re all warmed up, it’s time to jump into
the details. Being an active reader means that you are
actively taking part in the reading. Start by trying to vary
your reading rate. In places that require a little less at-
tention, try reading beyond your comfort level. One way
T
19 6 CHAPTER 8 Air and Air PollutionTypes and Sources of Air Pollution
LEARNING OBJECTIVES- Define primary and secondary air pollutants.air pollution and distinguish between
- List and describe their characteristics and sourthe seven major classes of air pollutants ces.
A
ir pollutionsuch as smoke can from come a forest from natural fire ignited sources, by
lightning However, human or gases activities from an release erupting many volcano. kinds
of to substances global air pollution. into the Some atmosphere of these and substances contribute are greatly harm-
ful when they are inhaled waters, or settle and on some land substances and su rf ace are
harmful chemistry of the atmosphereb ecause they alter .the
pollutants Although exist, many we focus different on the air
seven a regulatormost important y perspective: classes from par-
ticulate sulfur oxides, mattercarbon , nitrogen oxides, oxides, hy-
drocarbons, Air pollutants ozone, and are air often toxics.di -
mavided ry a nd into secondartwo categories, y (Figure 8. 6pri ). -
directly Primar^ y air pollutants from a source are releasedinto the at -^
mosphere. oxides, nitrogen They include oxides, carbon sulfur
dioxide, hydrocarbonsparticulate. matter, and
several Ozone, acids sulfur are called trioxide, secondarand y
air formed pollutantsfrom because chemical they reactions are
that take place in the atmosphere.
Major Classes of Air PollutantsParticulate matter consists of dusts and mists— thousands
of in the different atmosphere. types of Particulate solid and liquid matter particles includes suspended soil parti-
cles, Some particulate matter has toxic or c soot, lead, asbestos, sea salt, and sulfuric arcinogenic effects.acid droplets.air pollutionVarious chemicals
(gases, liquids, or solids) present in
the atmospherhigh enough leve in els
to harm humans, other organisms, or
materials.primary air
pollutants chemicals that enter Harmfuldi re ctly into theatmosphere due to (^)
either human activities or natural processes.
secondarpollutants y air Harmful
chemicals that form inthe atmosphere when
primary air pollutants react chemically with
one another or with natural components
of the atmosphere.
Human sources
Naturalsources
Primary air pollutants Secondary air pollutants
Most hydrocarbonsMost particulates
COSO 2 NO NOCO 22 HNOHNOH 2 O 232 O 3 PANsSOH 2 SO^34
saltsMostNO^3 andSO^42
Primary and secondary air pollutants
dirPrimarectly into the atmosphery air pollutants are emitted, unchanged, fre, whereas secondary air pollutants arom a source e
pr oduced from chemical reactions involving primary air pollutants.
r educing Particulate visibilitmatter y. Urban can scatter areas receive and absorb less sunlightsunlight,
than of particulate rural areas, matter partly in as the a result ai r. Particulate of greater matter quantitiecans
corrode the air is humid, metals, erode and soil buildings clothing and and sculptures draperies. when Lead
distances particles, which before are settling heavy, tend on the to travel ground relatively or a shorwater t
su rf ace.All particulate matter eventually settles out of the
atmosphere, suspended in but the atmosphere microscopic for particles weeks or can even remain years.
Trace to these amounts microscopic of hundreds particles; of different inhaling chemicals the particles bind
i ntroduces the human the bodychemicals,. Microscopic some particles of which are are considered toxic, into
Section Head
Figures
Key term
Term/Definition
Learning
Objectives
A typical sample page • Figure 0.1