* not completed

. Which of the following statements regarding atmospheric aerosols is/are true? (Please select all that apply)

The terms IP and PM₁₀ are approximately synonymous correct incorrect

Dust, pollen, mist and smog are all examples of atmospheric aerosols correct incorrect

The solid aerosol that results from sea spray has a composition that matches that of the bulk sea water correct incorrect

The chemical composition of dust reflects that of the solid surface where it came from correct incorrect

Black smoke aerosol occurs when carbon based fuels are burned under conditions where the fuel to oxidant ratio is smaller than the stoichiometric value correct incorrect

* not completed

. Which of the following statements regarding atmospheric aerosols is/are true? (Please select all that apply)

Water extracts of fly ash are typically somewhat acidic correct incorrect

Metals like lead and mercury that are present in fly ash are readily leachable correct incorrect

PAH values in urban atmospheres are often higher in summer than in winter correct incorrect

The grasshopper effect describes the northward movement of PAH compounds in the northern hemisphere correct incorrect

The aluminium industry is one source of PAH compounds correct incorrect

* not completed

. Which of the following statements regarding atmospheric aerosols is/are true? (Please select all that apply)

Volatile ammonia is released from soils when organic matter degrades under oxidizing conditions correct incorrect

Animal waste is a significant source of volatile ammonia            correct incorrect

Atmospheric solid ammonium sulfate particles are hydrophilic correct incorrect

O₃, O₂, and •OH all can take part in the oxidation of isoprene correct incorrect

The haze that is sometimes observed in a forested area on a warm day can be a natural phenomenon correct incorrect

* not completed

. Which of the following statements regarding atmospheric aerosols is/are true? (Please select all that apply)

Aerosol particles of an intermediate size may have longer atmospheric lifetimes than either smaller or larger particles correct incorrect

Stoke's Law plays a part in determining the extent of removal of aerosol particles in a Cyclone Precipitator correct incorrect

The mass of dissolved minor gases in the atmosphere is often much larger than that of particulates in the same volume correct incorrect

Coagulation refers to the chemical combination in the atmosphere of two gaseous species to form a solid or liquid particle correct incorrect

The term D in the coagulation equation (-dN/dt = 4πDCd_pN²) refers to particle density   correct incorrect

* not completed

. Which of the following statements regarding Arctic Haze is/are true? (Please select all that apply)

The Arctic Haze was first observed around the turn of the 21^st century correct incorrect

A significant atmospheric inversion exists in the Arctic during the late winter correct incorrect

The haze is due mostly to soil-derived particles from areas directly south of the Arctic correct incorrect

Settling of dark-coloured particles enhances the melting of snow cover correct incorrect

Sulfate-based particles are an important component of the haze correct incorrect

* not completed

. The concentration of aerosols range up to 500 μg m^-3 in which of the following geographical settings? (Please select all that apply)

Vegetated rural areas correct incorrect

Open Ocean correct incorrect

Arid areas correct incorrect

Sea shore correct incorrect

Urban atmosphere correct incorrect

* not completed

. Which of the following will increase the half-life (with respect to coagulation) of an aerosol particle?

Decrease in particle concentration correct incorrect

Increase in particle diameter correct incorrect

Increase in the diffusion coefficient (in air) correct incorrect

Change in the value of g (acceleration due to gravity) correct incorrect

Increase the size of the settling chamber correct incorrect

* not completed

. Which of the following statements about aerosol particles is/are true? (Please select all that apply)

Aerosol particles cover a size range from approximately 1 nm to 100 μm correct incorrect

Aerosol particles in the range of about 0.01 - 10 μm are the most stable in suspension correct incorrect

Aerosol particles less than 0.01 μm tend to settle correct incorrect

Aerosol particles greater than 10 μm tend to readily settle out correct incorrect

Aerosol particles are an environmental problem only in urban areas correct incorrect

* not completed

. Which of the following statements regarding control of particle emissions is/are true? (Please select all that apply)

Electrostatic precipitators operate under the principles of Stoke's Law correct incorrect

Settling chambers require maximizing the residence time of the gas stream in the chamber correct incorrect

Scrubbers are used only for removal of particles that are soluble in water correct incorrect

Electrostatic precipitators are one of the most effective means of removing very small particles correct incorrect

Control of particle emissions from diffuse sources is more difficult than from point sources correct incorrect

* not completed

. Which of the following aerosol control devices used in industry are effective for removal of particles less than 1 μm in size? (Please select all that apply)

Scrubber correct incorrect

Settling chamber correct incorrect

Cylcone correct incorrect

Electrostatic precipitator correct incorrect

Fabric filter correct incorrect