Atmosphere Chemistry

Atmosphere

helps protect living organisms from genetic damage by solar ultraviolet radiation, solar wind and cosmic rays

Composition of Atmosphere

78% nitrogen, 21% oxygen, 0.9% argon, 0.1% carbon dioxide and other gases

Significant Atmospheric Gases

Nitrogen, Oxygen, Argon, Carbon Dioxide, Water Vapor

Nitrogen

a gas which is fixed by bacteria and lightning to produce ammonia, which is used in the building of nucleotides and amino acids

Oxygen

a gas used by most organism for respirations

Argon

a noble gas obtained from the air as a byproduct of the production of oxygen and nitrogen

Carbon Dioxide

one of the trace gases used for photosynthesis by photosynthetic algae, plants and cyanobacteria

Water Vapor

a gas found in the lower layer or altitude of the atmosphere, accounting for 0.25% of it by mass

Carbon

main component of biological compounds and mineral deposits

Carbon Cycle

exchange of carbon among four reservoirs: atmosphere, ocean, land, fossil fuels

Importance of Carbon Cycle

carbon cycle approximates the flows of energy around the Earth, and the metabolism of every system

50% of the dry weight

carbon forms the structure of all life on earth as it makes up about _ of all life forms

-33 degrees celsius

Earth’s average temperature without greenhouse gases

carbon dioxide CO2 and methane CH4

contributes to the natural greenhouse effect that keeps the planet warm to sustain life

Carbon Cycle Diagram

when carbon is stored in different reservoirs other than the ocean, land, or air, it tends to

be released into the atmosphere as greenhouse gases

increased use of fossil fuels

causes imbalance in the release and consumption of carbon dioxide in nature

Air Pollutants

can be released directly into the atmosphere or can form as a result of chemical interaction involving precursor substances

Sources of Emissions

Man-made and Natural

Man-made Sources

burning of fossil fuels; industrial processes or solvent use; agriculture; waste treatment

burning of fossils fuels

coming from households, industry, electricity generation and transport

industrial processes and solvent use

exemplified by the chemical and mining industries

agriculture

methane (CH4) from cattle belching and nitrous oxide (N2O) from fertilizers

waste treatment

treatment plants produce direct emissions of greenhouse gases such as carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O)

Natural Resources

volcanic eruptions; windblown dust or soil dust; sea-salt spray; volatile organic compounds

volcanic eruptions

emit water vapor and toxic gases into the atmosphere, such as carbon dioxide, sulfur dioxide, hydrogen sulfide, hydrochloric acid, and carbon monoxide

windblown dust or soil dust

emitted through wind erosion and wildfires

sea-salt spray

contribute to global gas emissions; are a dominant contributor to the direct scattering of solar radiation; and are an important source of cloud droplets.

volatile organic compounds

chemical substances produced by plants and other organisms composed of carbon

depletion of the ozone layer

Influential greenhouse gases in the form of air pollutants cause __ in the atmosphere.

Ozone Layer

This layer covers the entire planet and protects life by absorbing harmful UV-B radiation from the Sun.