Topic 16: Air Quality
A ________ occurs when a layer of cool air is trapped under a layer of warm air in the
troposphere.
A. thermal (temperature) inversion
B. low-pressure system
C. high-pressure system
photochemical effect
convection current - ANS A.
In the troposphere, air becomes cooler as altitude increases. Sometimes, however, a
thermal (or temperature) inversion occurs when a layer of cool air is trapped under a
layer of warm air in the troposphere. This usually occurs on cold nights when air near the
ground cools and is trapped.
In a low-pressure system, warm air rises, expands, and cools, and precipitation occurs. A
high-pressure system contains air that cools, descends, and spreads, bringing fair
weather. A photochemical effect occurs when sunlight helps form air pollutants. A
convection current results from differences in gas density, which results from
differences in air temperature, where warm air rises and creates vertical currents.
\Acid deposition is formed when _____ and _____, released from combustion of fossil
fuels, reacts with oxygen and water in the atmosphere.
A. tropospheric ozone and nitrogen dioxide
B. carbon monoxide and lead
C. particulate matter and lead
D. heavy metals and photochemical smog
E. sulfur dioxide (SO2) and nitrogen oxide (NOx) - ANS E.
Sulfur dioxide (SO2) and nitrogen oxide (NOX) gases come from burning fossil fuels in
coal-fired power plants and vehicle exhaust, and are the most abundant acidifying
pollutants. They react with water and oxygen in the atmosphere to produce sulfuric and
nitric acids. Acid deposition negatively affects forests and lakes. Tropospheric ozone is a
secondary pollutant, created by the reaction of nitrogen oxides and volatile
carbon-containing chemicals in the presence of sunlight. This pollutant can cause
respiratory problems. Nitrogen dioxide is a source of acid deposition, because they
combine with oxygen and hydrogen in the air to form nitric acid. Carbon monoxide is a
colorless, odorless gas produced by the combusion of fuel. It is hazardous because it
binds to the hemoglobin in red blood cells, and can cause death. Lead is a heavy metal
that enters the atmosphere as a particulate pollutant. It accumulates in body tissues and
can damage the nervous system. Particulate matter, composed of small, suspended
particles in the air, include dust, soot, sulfates, and nitrates. Small particles can damage
the lung, heart, and brain. Lead is a heavy metal that enters the atmosphere as a
, particulate pollutant. It accumulates in body tissues and can damage the nervous
system. Heavy metals, including lead and mercury, are toxic to humans and other
animals, and are released from the combustion of fossil fuels, waste incineration, and
metal smelting. Heavy metals can accumulate to toxic levels, and can cause death.
Photochemical smog is created when sunlight drives certain chemical reactions between
primary pollutants and compounds in the atmosphere. It contains NO2, and appears as a
brownish haze over cities.
\Approximately 80 percent of our atmosphere is made up of which of the following?
A. N2
B. O2
C. CO2
D. H2O - ANS A.
Nitrogen gas (N2) makes up 80 percent of the atmosphere.
By volume, dry air contains 78.09% nitrogen, 20.95% oxygen, 0.93% argon, 0.039%
carbon dioxide, and small amounts of other gases.
\Compared with 1970, what happened to emissions of the five primary pollutants in the
United States in 2011?
A. They are much higher.
B. They are about the same.
C. They have been significantly reduced.
D. We don't know; we didn't take measurements in 1970.
E. They are so low, we no longer monitor them. - ANS C.
In 2011, U.S. emissions of carbon monoxide, nitrous oxides, volatile organic compounds,
sulfur dioxide, and particulate matter have been significantly reduced compared to 1970.
\Generalized global air circulation and precipitation patterns are caused by __________.
A. air masses that are dried and heated over continental areas that rise, cool aloft, and
descend over oceanic areas followed by a return flow of moist air from ocean to land,
delivering high amounts of precipitation to coastal areas
B. polar, cool, moist high-pressure air masses from the poles that move along the
surface, releasing precipitation along the way to the equator, where they are heated and
dried
C. the revolution of Earth around the sun
D. rising, warm, moist air masses that cool and release precipitation as they rise and
then, at high altitude, cool and sink back to the surface as dry air masses after moving
north or south of the tropics
E. mountain ranges that deflect air masses containing variable amounts of moisture -
ANS D.
Generalized global air circulation and precipitation patterns are caused by rising, warm,
moist air masses that cool and release precipitation as they rise and then, at high
altitude, cool and sink back to the surface as dry air masses after moving north or south
A ________ occurs when a layer of cool air is trapped under a layer of warm air in the
troposphere.
A. thermal (temperature) inversion
B. low-pressure system
C. high-pressure system
photochemical effect
convection current - ANS A.
In the troposphere, air becomes cooler as altitude increases. Sometimes, however, a
thermal (or temperature) inversion occurs when a layer of cool air is trapped under a
layer of warm air in the troposphere. This usually occurs on cold nights when air near the
ground cools and is trapped.
In a low-pressure system, warm air rises, expands, and cools, and precipitation occurs. A
high-pressure system contains air that cools, descends, and spreads, bringing fair
weather. A photochemical effect occurs when sunlight helps form air pollutants. A
convection current results from differences in gas density, which results from
differences in air temperature, where warm air rises and creates vertical currents.
\Acid deposition is formed when _____ and _____, released from combustion of fossil
fuels, reacts with oxygen and water in the atmosphere.
A. tropospheric ozone and nitrogen dioxide
B. carbon monoxide and lead
C. particulate matter and lead
D. heavy metals and photochemical smog
E. sulfur dioxide (SO2) and nitrogen oxide (NOx) - ANS E.
Sulfur dioxide (SO2) and nitrogen oxide (NOX) gases come from burning fossil fuels in
coal-fired power plants and vehicle exhaust, and are the most abundant acidifying
pollutants. They react with water and oxygen in the atmosphere to produce sulfuric and
nitric acids. Acid deposition negatively affects forests and lakes. Tropospheric ozone is a
secondary pollutant, created by the reaction of nitrogen oxides and volatile
carbon-containing chemicals in the presence of sunlight. This pollutant can cause
respiratory problems. Nitrogen dioxide is a source of acid deposition, because they
combine with oxygen and hydrogen in the air to form nitric acid. Carbon monoxide is a
colorless, odorless gas produced by the combusion of fuel. It is hazardous because it
binds to the hemoglobin in red blood cells, and can cause death. Lead is a heavy metal
that enters the atmosphere as a particulate pollutant. It accumulates in body tissues and
can damage the nervous system. Particulate matter, composed of small, suspended
particles in the air, include dust, soot, sulfates, and nitrates. Small particles can damage
the lung, heart, and brain. Lead is a heavy metal that enters the atmosphere as a
, particulate pollutant. It accumulates in body tissues and can damage the nervous
system. Heavy metals, including lead and mercury, are toxic to humans and other
animals, and are released from the combustion of fossil fuels, waste incineration, and
metal smelting. Heavy metals can accumulate to toxic levels, and can cause death.
Photochemical smog is created when sunlight drives certain chemical reactions between
primary pollutants and compounds in the atmosphere. It contains NO2, and appears as a
brownish haze over cities.
\Approximately 80 percent of our atmosphere is made up of which of the following?
A. N2
B. O2
C. CO2
D. H2O - ANS A.
Nitrogen gas (N2) makes up 80 percent of the atmosphere.
By volume, dry air contains 78.09% nitrogen, 20.95% oxygen, 0.93% argon, 0.039%
carbon dioxide, and small amounts of other gases.
\Compared with 1970, what happened to emissions of the five primary pollutants in the
United States in 2011?
A. They are much higher.
B. They are about the same.
C. They have been significantly reduced.
D. We don't know; we didn't take measurements in 1970.
E. They are so low, we no longer monitor them. - ANS C.
In 2011, U.S. emissions of carbon monoxide, nitrous oxides, volatile organic compounds,
sulfur dioxide, and particulate matter have been significantly reduced compared to 1970.
\Generalized global air circulation and precipitation patterns are caused by __________.
A. air masses that are dried and heated over continental areas that rise, cool aloft, and
descend over oceanic areas followed by a return flow of moist air from ocean to land,
delivering high amounts of precipitation to coastal areas
B. polar, cool, moist high-pressure air masses from the poles that move along the
surface, releasing precipitation along the way to the equator, where they are heated and
dried
C. the revolution of Earth around the sun
D. rising, warm, moist air masses that cool and release precipitation as they rise and
then, at high altitude, cool and sink back to the surface as dry air masses after moving
north or south of the tropics
E. mountain ranges that deflect air masses containing variable amounts of moisture -
ANS D.
Generalized global air circulation and precipitation patterns are caused by rising, warm,
moist air masses that cool and release precipitation as they rise and then, at high
altitude, cool and sink back to the surface as dry air masses after moving north or south
