Chemistry of the Atmospheric Cycle

• a protective blanket which nurtures life on the earth and protects it from the hostile environment of outer space

  atmosphere
• earth's atmosphere three billion or four billion years ago were called primordial soup which mainly consisted of?

  ammonia, methane, and water
• the radiation from the sun

  ultraviolet radiation
• another important source of oxygen other than photosynthesis used by the primitive organisms is?

  photodecomposition of water vapor by UV light
• a very stable molecule with its triple bond

  molecular nitrogen
• nitrogen gas is converted into nitrates and other compounds
• lightning also produces nitrates from nitrogen gas
• is converted to nitrate salts in the soil

  nitric acid
• Denitrification reverses nitrogen fixation to complete the cycle
• is removed through respiration and combustion to produce carbon dioxide

  atmospheric oxygen
• major mechanism by which molecular oxygen is regenerated from carbon dioxide and water

  photosynthesis
• layers of atmosphere from bottom to top

  • lithosphere
  • troposphere
  • stratosphere
  • mesosphere
  • thermosphere
  • exosphere
• how many percent of the total air and all atmosphere's water vapor is in the troposphere?

  80
• what is stratosphere made of?

  nitrogen, oxygen, and ozone
• ozone serves to prevent harmful UV rays from reaching Earth's surface
• in this layer of the atmosphere, the concentration of ozone and other gases is low and the temperature decreases with the increasing altitude

  mesosphere
• an attempt to define a boundary between the Earth's atmosphere and outer space

  Karman line or von Karman line
• uppermost layer of the atmosphere

  thermosphere or ionosphere
• what is thermosphere consists of?

  helium, atomic nitrogen, and atomic oxygen
• a substance present in greater than natural concentration as a result of human activity

  pollutant
• are not classified as pollutants unless they have some detrimental effect and cause deviations from the normal composition of an environment

  contaminants
• the most abundant natural atmospheric constituent

  carbon dioxide
• the increase in atmospheric carbon dioxide may well cause general atmospheric warming or greenhouse effect
• carbon monoxide can be a serious health threat because it prevents blood from transporting oxygen to body tissues
• a reaction product of sulfur-containing fuels high-sulfur coal.

  sulfur dioxide
• is the normally predominant contributor to acid precipitation

  sulfuric acid
• most abundant hydrocarbon in the atmosphere

  methane
• one of the least reactive atmospheric hydrocarbons and is produced by diffuse sources

  methane
• are very small particles that serve as bodies for atmospheric water vapor to condense upon and are essential for the formation of rain drops

  condensation nuclei
• particles ranging from aggregates of a few molecules to pieces of dust readily visible to the naked eye are commonly found in the atmosphere

  particulate matter
• are colloidal-sized particles in the atmosphere

  aerosols
• are formed by grinding up bulk matter are known as?

  dispersion aerosols
• are particles formed from chemical reactions of gases are ?

  condensation aerosols
• the simplest means of particulate matter removal

  sedimentation
• may be employed for the removal of particles from gas streams by simply settling under the influence of gravity

  gravitational settling chambers
• inertial mechanism are effective for particle removal which depends on the radius of the path.
• devices utilizing particle removal by inertia are called?

  dry centrifugal collectors or cyclones
• consist of fabrics that allow the passage of gas but retain particulate matter

  fabric filters
• fabric filtration is aided by the development of mechanically strong heat resistant fabrics to control particulate emissions
• this passes gas through a device which leads the gas stream through a converging section, throat, and diverging section

  venturi scrubber