1)  In air, which of the following equalities is true?

a.  mass conc. = volume conc.

b.  mass conc. = molar conc.

c.  molar conc. = volume conc.

2)  The mixing ratio is the same as all of the following EXCEPT the

a.  mass concentration

b.  molar concentration

c.  partial pressure / total pressure

d.  volume concentration

3) Which has a higher density?

  1. dry air
  2. moist air
  3. they both have the same densities

4) Which of the following is NOT a criteria pollutant?

  1. CO
  2. CO2
  3. O3
  4. NO2
  5. PM2.5

5) Ozone is not directly emitted but forms in the atmosphere from reactions of

  1. Carbon dioxide and particulate matter
  2. Chlorofluorocarbons
  3. Nitrogen oxides and volatile organic compounds
  4. Particulate matter and volatile organic compounds

6) Nitrogen oxides (NOx) are the sum of

  1. N2 + NO + NO2
  2. NO + NO2
  3. NO + N2O
  4. NO2 + N2O

7) In PM2.5, the “2.5” refers to

  1. Particles larger than 2.5 µm
  2. Particles larger than 2.5 mm
  3. Particles less than 2.5 µg
  4. Particles smaller than 2.5 µm
  5. Particles smaller than 2.5 mm

8) Carbon monoxide originates mainly from

  1. Combustion of fuels
  2. Oxidation of carbon dioxide
  3. Secondary reactions
  4. Wind-blown sources

9) All of the following criteria pollutants cause respiratory irritation EXCEPT

  1. Carbon monoxide
  2. Ozone
  3. Nitrogen dioxide
  4. Particulate matter
  5. Sulfur dioxide

10) Which criteria pollutant has both primary and secondary sources

  1. Carbon monoxide
  2. Lead
  3. Ozone
  4. Particulate matter
  5. Sulfur dioxide

11) Average global temperatures have risen by approximately how much over the 20th century?

  1. 0 °C
  2. 1 °C
  3. 3 °C
  4. 5 °C

12) Average global temperatures have risen by approximately how much over the 20th century?

  1. 0 °C
  2. 1 °C
  3. 3 °C
  4. 5 °C

13) By how much do scientists estimate that global sea level rose in the 20th century?

  1. Zero
  2. 6-9 inches
  3. 3-4 feet
  4. 21-23 feet

14) Why is Earth warm enough to support life?

  1. Infrared radiation leaving Earth’s surface is absorbed by gases in the lower atmosphere.
  2. Radiation from the sun is absorbed by ozone in the stratosphere.
  3. X-rays and gamma rays excite gas molecules in the lower atmosphere.

15) Peak solar irradiance occurs in which wavelengths?

  1. Infrared
  2. Gamma
  3. Microwave
  4. Visible

16) Peak Earth irradiance occurs in which wavelengths?

  1. Infrared
  2. Gamma
  3. Microwave
  4. Visible

17) A greenhouse gas is one that

  1. Absorbs shortwave/visible radiation
  2. Absorbs longwave/infrared radiation
  3. Reflects shortwave/visible radiation
  4. Reflects longwave/infrared radiation

18) Which of the following is not a greenhouse gas?

  1. Carbon dioxide
  2. Chlorofluorocarbons
  3. Nitrogen
  4. Water vapor

19) Without the atmosphere’s natural greenhouse effect, Earth’s temperature would be

  1. 10-20 °C warmer
  2. 30-40 °C warmer
  3. 10-20 °C cooler
  4. 30-40 °C cooler

20) The mass flow rate can be calculated as the product of

  1. concentration and velocity
  2. concentration and volume flow rate
  3. mixing ratio and velocity
  4. velocity and volume flow rate

21) Flux may be due to all of the following EXCEPT

  1. advection
  2. chemical reactions
  3. molecular diffusion
  4. turbulent diffusion

22) Fick’s law applies to

  1. advection
  2. chemical reactions
  3. molecular diffusion
  4. turbulent diffusion

23) d(CV)/dt refers to the rate of change in

  1. coefficient of variation
  2. flow rate
  3. mass
  4. volume

24) In the airshed model, which of the following would unquestionably increase the steady-state SO2 concentration?

  1. higher emission rate and higher wind speed
  2. higher emission rate and lower wind speed
  3. lower emission rate and lower wind speed
  4. lower emission rate and higher wind speed

25) The Chapman mechanism describes the balance of

  1. O, O2, O3
  2. O, VOC, NOx
  3. O3, CFCs
  4. O3, OH, HO2

26) In atmospheric chemistry, a heterogeneous reaction occurs between

  1. a compound and M
  2. a compound and UV light
  3. a gas and a solid
  4. a radical and a non-radical

27) Which reaction absorbs most UVB radiation?

  1. O2 + hn ® 2 O
  2. O + O2 ® O3
  3. O3 + hn ® O2 + O
  4. O + O3 ® 2 O2

28) Which of the following is directly responsible for the catalytic destruction of ozone?

  1. CCl3F
  2. Cl
  3. Cl2
  4. ClONO2

29) Which of the following is considered a chlorine reservoir?

  1. CCl3F
  2. Cl
  3. Cl2
  4. ClONO2

30) Which of the following is a form of active chlorine?

  1. CCl3F
  2. Cl
  3. Cl2
  4. ClONO2

31) The severity of the Antarctic ozone hole is worst during the Southern Hemisphere

  1. winter
  2. spring
  3. summer
  4. fall

32) In the Southeastern US, the two major constituents of PM2.5 are

  1. crustal material and nitrate
  2. nitrate and sulfate
  3. elemental carbon and organic carbon
  4. organic carbon and sulfate

33) Secondary aerosol may be composed of any of the following EXCEPT

  1. ammonium
  2. elemental carbon
  3. nitrate
  4. organic carbon
  5. sulfate

34) On the basis of number concentration, the majority of particles are found in which mode?

  1. Ultrafine
  2. Accumulation
  3. Coarse

35) On the basis of surface area concentration, the majority of particles are found in which mode?

  1. Ultrafine
  2. Accumulation
  3. Coarse

36) On the basis of mass concentration, the majority of particles are found in which mode?

  1. Ultrafine
  2. Accumulation
  3. Coarse

37) For spherical particles larger than ~5 mm, Stokes law describes the

  1. buoyancy force
  2. drag force
  3. slip correction
  4. terminal settling velocity

38) The Knudsen number is Kn = 2l/Dp. The free-molecular regime corresponds to

  1. Kn < 1
  2. Kn ~ 1
  3. Kn > 1

39) In the free-molecular regime, the actual settling velocity is

  1. slower
  2. the same
  3. faster

compared to that predicted by Stokes law.

40) For coarse particles, the Cunningham slip-correction coefficient Cc is closest to

  1. 0
  2. 0.1
  3. 1
  4. ¥ (infinity)

41) Brownian motion is due to

  1. the kinetic energy of particles
  2. the random motion of air molecules
  3. the thermal energy of particles
  4. the turbulent motion of air
  5. American Gladiators

42) The Stokes number is the ratio of

  1. Knudsen number / settling velocity
  2. settling velocity / gravitational acceleration
  3. stopping distance / settling velocity
  4. stopping distance / length of interest

43) In the previous figure, the Stokes number for the particle shown was

  1. < 1
  2. = 1
  3. > 1

44) Which of the following is NOT considered a particle collection mechanism in filters?

  1. diffusion
  2. gravitational settling
  3. impaction
  4. interception

45) Which two collection devices are best for ultrafine particles?

  1. cyclones and filters
  2. cyclones and settling chambers
  3. ESPs and filters
  4. ESPs and settling chambers

46) For the following reaction, which is the corresponding equilibrium expression?

A + B ® C + D

  1. K = -k[A][B]
  2. K = +k[C][D]
  3. K = [A][B] / [C][D]
  4. K = [C][D] / [A][B]

47) For the following elementary reaction, which is the corresponding rate expression?

A + B ® C + D

  1. r = -k[A][B]
  2. r = +k[C][D]
  3. r = [A][B] / [C][D]
  4. r = [C][D] / [A][B]

48) Two hydroperoxy radicals can react together to form hydrogen peroxide as follows:

HO2· + HO2· ® H2O2 + O2

What expression describes the rate of change of the mole fraction of HO2·,

  1. -[H2O2][O2] / [HO2·]2
  2. -½ k [HO2·]2
  3. -2 k [HO2·]2

49) What is d[N2O5]/dt in the following mechanism?

O3+ NO2 ® NO3 + O2 R1

NO3+ NO ® 2 NO2 R2

NO2+ NO3 ® N2O5 R3

N2O5 ® NO2+ NO3 R4

N2O5 (+ H2O) ® 2 HNO3 R5 (first-order)

  1. k3[NO2][NO3]
  2. k3[NO2][NO3] -k4[N2O5] - k5[N2O5]
  3. -k4[N2O5]
  4. -k4[N2O5] - k5[N2O5]

50) What is the characteristic time of N2O5?

O3+ NO2 ® NO3 + O2 R1

NO3+ NO ® 2 NO2 R2

NO2+ NO3 ® N2O5 R3

N2O5 ® NO2+ NO3 R4

N2O5 (+ H2O) ® 2 HNO3 R5 (first-order)

  1. 1 / {k3[NO2][NO3]}
  2. 1 / k4
  3. 1 / (k4 + k5)
  4. 1 / {(k4 + k5)[N2O5]}

51) Radicals are extremely reactive because they

  1. are negatively charged
  2. are positively charged
  3. have an unpaired electron
  4. have a triple bond

52) Radicals are extremely reactive because they

  1. are negatively charged
  2. are positively charged
  3. have an unpaired electron
  4. have a triple bond

53) The first step in ozone photolysis O3 + hn ® O(1D) · + O2 is

  1. chain initiating
  2. chain propagating
  3. chain terminating
  4. none of the above

54) Hydrogen abstraction is always the first step in the reaction of OH· with

  1. alkanes
  2. alkenes
  3. aromatics
  4. all of the above

55) Addition of OH· is always the first step in its reaction with

  1. alkanes
  2. alkenes
  3. aromatics
  4. all of the above

56) Ozone is helpful in the ______and harmful in the ______.

  1. mesosphere, stratosphere
  2. stratosphere, troposphere
  3. troposphere, stratosphere

57) In urban areas, ozone tends to peak around

  1. midnight
  2. the morning rush hour
  3. early afternoon
  4. the evening rush hour

58) The primary photolytic cycle describes

  1. Carbon monoxide and methane chemistry
  2. Ozone formation from VOCs
  3. Photolysis reactions that produce OH
  4. The balance of ozone and NOx

59) What is jNO2?

  1. Characteristic lifetime of NO2
  2. Equilibrium constant for NO + ½ O2 « NO2
  3. Henry’s constant for NO2
  4. Photolysis rate constant for NO2

60) The assumption that dC/dt ≈ 0 for species whose characteristic lifetime is very small is the

  1. Photostationary state relation (PSSR)
  2. Primary photolytic cycle
  3. Initiation, propagation, and termination model
  4. Pseudo-steady-state approximation (PSSA)

61) According to the photostationary state relation (PSSR), O3 is proportional to

  1. [NO2]/[NO]
  2. [O]/[O2]
  3. [OH]/[HO2]
  4. [VOC]/[NOx]

62) In the VOC-limited regime, reductions in NOx are likely to result in

  1. higher ozone
  2. lower ozone
  3. unchanged ozone

63) Which of the following reactions is the most permanent termination step, i.e. it does not produce a temporary reservoir for radicals?

  1. HO2· + HO2· ® H2O2 + O2
  2. NO + OH· ® HONO
  3. NO2 + OH· ® HNO3

64) Which of the following is NOT true about peroxyacetylnitrate (PAN)?

  1. It causes respiratory irritation
  2. It is a reservoir for NOx
  3. It is an intermediate in VOC chemistry
  4. It thermally degrades

65) The ozone production rate equals the rate of which reaction?

  1. H + O2 + M ® HO2 + M
  2. HO2 + HO2 ® H2O2 + O2
  3. HO2 + NO ® NO2 + OH
  4. RH + OH ® R + H2O

66) In the NOx-limited regime, ozone production is

  1. linear with [NO]
  2. inversely proportional to [NOx]
  3. linear with [RH]
  4. proportional to [NO]2

67) The ozone production efficiency describes the

  1. amount of O3 formed per NOx removed
  2. amount of O3 formed per OH radical
  3. rate of NOx loss
  4. rate of O3 production

68) Which term is typically not considered in a single box model?

  1. advection
  2. deposition
  3. diffusion
  4. emissions
  5. reactions

69) With entrainment where the mixing depth is growing, how will the concentration change?

  1. increase
  2. decrease
  3. no change

70) Plentiful mixing in the atmosphere is described by what conditions?

  1. inversion
  2. neutral
  3. stable
  4. unstable

71) With an inversion, dT/dz is

  1. < 0
  2. = 0
  3. > 0
  4. variable

72) The adiabatic lapse rate is approximately

  1. 0.1 °C/km
  2. 1 °C/km
  3. 10 °C/km
  4. 100 °C/km

73) What type of inversion is characterized by downward moving air?

  1. advective
  2. frontal
  3. radiation
  4. subsidence

74) In an Eulerian three-dimensional model, which term is usually assumed to be zero?

  1. advection
  2. deposition
  3. molecular diffusion
  4. dispersion (turbulent diffusion)

75) In pollutant transport models, K-theory describes

  1. advection in unstable conditions
  2. chemical reaction rates
  3. equilibrium chemistry
  4. parameterization of turbulence

76) A Lagrangian box model is an example of

  1. receptor-oriented modeling
  2. source-oriented modeling
  3. three-dimensional modeling

77) What is closest to the actual number concentration of particles outside?

  1. 1 per cm3 (1 cm-3)
  2. 100 cm-3
  3. 10,000 cm-3
  4. 1,000,000 cm-3

78) What size particle deposits most efficiently in the lungs?

  1. 1 nm
  2. 10 nm
  3. 100 nm
  4. 1000 nm

79) On the basis of number concentration, the majority of particles are found in which mode?

  1. ultrafine
  2. accumulation
  3. coarse

80) On the basis of surface area concentration, the majority of particles are found in which mode?

  1. ultrafine
  2. accumulation
  3. coarse

81) On the basis of mass concentration, the majority of particles are found in which mode?

  1. ultrafine
  2. accumulation
  3. coarse

82) For spherical particles larger than ~5 mm, Stokes law describes the

  1. buoyancy force
  2. drag force
  3. slip correction
  4. terminal settling velocity

83) The Knudsen number is Kn = 2l/Dp. The free-molecular regime corresponds to

  1. Kn < 1
  2. Kn ~ 1
  3. Kn > 1

84) In the free-molecular regime, the actual settling velocity is

  1. slower
  2. the same
  3. faster

compared to that predicted by Stokes law.

85) For large particles, the Cunningham slip-correction coefficient C is closest to

  1. 0
  2. 0.1
  3. 1
  4. ¥ (infinity)

86) For large particles, the Cunningham slip-correction coefficient C is closest to

  1. 0
  2. 0.1
  3. 1
  4. ¥ (infinity)

87) For large particles, the Cunningham slip-correction coefficient C is closest to

  1. 0
  2. 0.1
  3. 1
  4. ¥ (infinity)

88) Brownian motion is due to

  1. the kinetic energy of particles
  2. the random motion of air molecules
  3. the thermal energy of particles
  4. the turbulent motion of air

89) Condensation and evaporation result in

  1. a change in number concentration and size
  2. a change in number concentration only
  3. a change in size only
  4. it depends

90) Coagulation results in

  1. a change in number concentration and size
  2. a change in number concentration only
  3. a change in size only
  4. it depends

91) What is the natural range of visibility in the eastern US?

  1. 10 mi
  2. 20 mi
  3. 50 mi
  4. 100 mi

92) With Rayleigh scattering, by what factor is blue light (l = 0.46 mm) scattered more intensely than is red light (l = 0.66 mm)?

  1. same
  2. 1.4
  3. 4.2
  4. 14

93) Which component of bext do you think is called the Rayleigh scattering coefficient?

  1. bag
  2. bap
  3. bsg
  4. bsp

94) For a black object, at x = 0 (at the object), what is I(0)?

  1. 0
  2. 1
  3. it depends

95) As you move farther away from a non-black object (x increases), what happens to I(x)?

  1. decreases
  2. increases
  3. stays the same
  4. it depends

96) As you move farther away from the object (x increases), what happens to Ibg(x)?

  1. decreases
  2. increases
  3. stays the same
  4. it depends

97) For the black object, what is the contrast at zero distance from the object, C(0)?