Chemistry, HSSC-Punjab First Year. This chapter is split into 26 topics and has
620 practice questions. The topics covered are listed below, followed by
10 free sample questions from the chapter.
Topics in this chapter
Chlorofluorocarbons and ozone depletion24 questions
PAHs POPs and VOCs24 questions
Troposphere and stratosphere23 questions
Laws regulations and control measures22 questions
Smog classical and photochemical24 questions
Oxides of nitrogen NOx24 questions
Acid rain chemistry27 questions
Greenhouse effect and global warming25 questions
Atmospheric layer calculations21 questions
Atmosphere exercise-style questions26 questions
Particulate matter24 questions
Composition of the atmosphere24 questions
Oxides of sulfur and acid deposition23 questions
Pollution control technologies24 questions
Gas amounts and concentrations in air22 questions
Natural and human-made sources of air pollution24 questions
Hydrocarbons low-altitude ozone and heavy metals24 questions
Air pollution and human health23 questions
Air Quality Index AQI29 questions
Primary and secondary air pollutants24 questions
Monitoring air quality and designing experiments23 questions
Mesosphere thermosphere and layer comparison25 questions
Human activities fossil fuels and deforestation24 questions
Factors affecting air quality22 questions
Economic social and political issues of air pollution21 questions
Oxides of carbon and combustion24 questions
Sample questions: Atmosphere
10 sample questions with the correct answer and an explanation. Try to answer each one before reading the explanation.
Q1. On what basis are the four layers of the atmosphere distinguished?
A. The change in temperature with increasing altitude(correct answer)
B. The change in colour of the gases
C. The change in the percentage of oxygen only
D. The amount of cloud in each layer
Answer: A.The chapter states the four distinct layers are determined by the change in temperature observed with increasing altitude.
Q2. At about what concentration does low-altitude ozone become toxic according to the chapter?
A. Above 1000 ppm, which is a lethal concentration
B. Above 100 parts per million(correct answer)
C. Above 0.1 ppm, which is typical of city air
D. Above 1 part per million, as in the air quality guidelines
Answer: B.The chapter says ozone is non-toxic in small concentrations but toxic above 100 ppm (the figure is higher than typical regulatory values).
Q3. Which are the major sources of heavy metals in the atmosphere, according to the chapter?
A. Lightning, rain and wind
B. Metallurgy, battery waste and incineration(correct answer)
C. Swamps, algae and volcanoes
D. Respiration, photosynthesis and decay
Answer: B.Heavy metals are released from industrial processes, transport and other human activities; metallurgy, battery waste and incineration are the major sources.
Q4. Which of these make up smog according to the chapter?
A. Fine dust or soot, condensed water vapour and poisonous gases such as SO₂, NOₓ, O₃ and CO(correct answer)
B. Only water vapour and oxygen from the evaporation of oceans and lakes
C. Only pollen, spores and animal debris carried by the wind from fields
D. Only nitrogen and argon from the lower layers of the atmosphere
Answer: A.The chapter describes smog as dust or soot, water vapour, gases, secondary pollutants, unburned hydrocarbons, VOCs and PM.
Q5. Which type of smog is considered more dangerous in the chapter?
A. Industrial smog
B. Neither is dangerous
C. Photochemical smog(correct answer)
D. They are equally dangerous
Answer: C.The chapter says photochemical smog is more dangerous because it can cause heart palpitations, pneumonia and lung cancer.
Q6. Which statement correctly compares classical smog and photochemical smog?
A. Classical smog needs sunlight and photochemical smog is rich in SOₓ
B. Both are caused only by CFCs and are found in the stratosphere
C. Both are made only of water vapour and differ only in temperature
D. Classical smog is rich in SOₓ and photochemical smog needs sunlight and NOₓ with VOCs(correct answer)
Answer: D.Q.14.3a asks to differentiate them: classical smog stems mainly from SOₓ; photochemical smog from NOₓ and VOCs in sunlight.
Q7. What is global warming?
A. A change in the Earth's orbit that alters the seasons
B. A long-term rise in the Earth's average surface temperature due to human activities(correct answer)
C. A short-term fall in temperature in winter because of snow
D. A decrease in the Sun's radiation reaching the surface
Answer: B.The chapter defines global warming as the long-term rise in Earth's average surface temperature due to human activities, mainly emission of greenhouse gases.
Q8. What is the greenhouse effect?
A. The cooling of the atmosphere by clouds and by snow-covered surfaces
B. The destruction of the ozone layer by CFCs in the stratosphere
C. The progressive warming of the Earth's surface due to the blanketing effect of greenhouse gases(correct answer)
D. The formation of acid rain from SO₂ and NOₓ in the troposphere
Answer: C.The chapter defines it as progressive warming of the earth's surface due to the blanketing effect of GHGs in the atmosphere.
Q9. Exercise Q.2a: name three natural sources of air pollutants and the pollutant each releases.
A. Volcanoes − gases and PM; lightning − NOₓ; algae − H₂S(correct answer)