Atmospheric Pollutants Questions And Answers (Page 4 of 4) in pdf

Atmospheric Pollutants Questions And Answers Page 4

25.

Distinguish between ultrafine, Aiken nuclei, and accumulation mode particles.

Ultrafine particles have particle diameters <0.01µm, Aiken nuclei are 0.01-

0.1 µm, and accumulation mode particles are 0.1-1 µm.

26.

Atmospheric particles vary in their chemical composition. Why is this the case?

Chemical composition of particles reflects the nature of sources from which

they were emitted, particle formation in the atmosphere, and their

atmospheric history.

27.

Describe how physical/chemical properties of particles affect their atmospheric

behavior.

Larger, heavier particles settle out more rapidly than smaller, lighter

particles. Particles with diameters in the range of visible light scatter light

very effectively. Hygroscopic particles absorb H

O. Small particles can

collide with each other and grow into larger particles.

28.

Describe the relative significance of metals found in particulate matter.

Particulate matter is a major source of metal pollution in the environment.

Most notable is Hg in flyash from the burning of coal.

Atmospheric Pollutants Questions And Answers Page 4