6. notes and revision Flashcards
Atmosphere
this is a mixture of gases surrounding the planet held by gravity.
Ozone
This is a gas made up of three oxygen atoms
Stratospheric ozone
This is the ozone that exists above the earth and protects us from UV rays from the sun. It is good ozone.
How is stratospheric ozone formed
When UV is absorbed, oxygen molecules are split into oxygen atoms. These oxygen atoms react with oxygen molecules to form stratospheric ozone.
Advantages of UV rays
Stimulates production of vitamin D
Used in lasers
examples of Ozone depleting substances
CFCs, HCFCs, Halons
CFCs eg refridgerators, pesticides, spray cans; they all release a chlorine that depletes ozone
Nitrogen oxides; from intensive farming with nitrates
Disadvantages of UV rays
cataract eyes
skin cancer
destroy phytoplanton
The montreal protocol
The Montreal Protocol was an international agreement made by the UN after the discovery of the ozone hole in Antarctica. This treaty was an agreement by countries to phase out the use of ozone depleting substances eg cfcs
the ozone hole
The ozone hole was a large area above the the stratosphere over antarctica with a large depleted ozone hole.
Urban air pollution
This is when harmful substances contaminate the atmosphere resulting from urbanisation.
Primary pollution
This is when pollutants are emitted directly from a process.
Secondary pollution
This is when a primary pollutant reacts with other chemicals already in the atmosphere.
examples of secondary pollutants
Trapospheric ozone
sulfur dioxide
nitrogen dioxide
Tropospheric ozone
Tropospheric ozone is ozone on the ground-level of the Earth’s surface.
Ozone GWP vs CO2s
Ozone is a greenhouse gas with a global warming potential of 2000x of carbon.
How is tropospheric ozone formed
Nitrogen oxides from burning fossils react with chemicals under sunlight producing tropospheric ozone
Photochemical smog definition and formation
this is when a mixture of pollutants form a brownish haze and odor
it is formed when
Nitrogen dioxide reacts with chemicals in the atmosphere and combustion of fossil fuels produced by cars under the presence of sunlight
Thermal inversion
this is when a layer of warm air traps cooler air near the surface of the earth enhancing photochemical smog
what enhances photochemical smog
Thermal inversion
Ways to reduce urban air pollution
ARR
Reduce combustion of fossil fuels
Renewable energies as an alternative
Legislation eg carbon tax
education to raise awareness
afforestation
Acid deposition
Acid deposition is the coming down od acids in form of dry and wet deposition.
general term for acid coming down from the air. Often, the acid comes down in the form of rain (or snow), this is called wet deposition. Dry deposition is when the acid comes down as ash or dry particles.
Acids
Acids are chemicals that prdduce h+.
are able to give a hydrogen ion (H+) away.
Ph scale
it measures acidity.
increasing acidity 0 to 4
neutral 5 to 9
increasing alkalinity 9 to 14
how are acids measure
The acidity of solutions is measured using the pH scale.
Pollutants leading to acid deposition
sulfur dioxide
nitrogen oxide
Sources of Pollutants leading to acid deposition
volcanic eruptions
lightening
Effects of acid deposition
Trees are weakened and may die
Reduced PH in water killing aquatic life
reduced ph in soil reducing its ability to hold nutrients
Pollution management strategies for acid deposition
rrr
Use alternatives to fossil fuels eg renewable energy
clean up and restoration
Legislation
Education
