That tiny bit at the end Flashcards
What is sedimentation?
Iron or aluminium sulfate is added to the water to make fine particles clump together and settle at the bottom of the container.
What is chlorination?
Chlorine gas is bubbled through the water to kill harmful bacteria and other microbes.
What is filtration?
As rainwater contains insoluble particulates that are unsafe to drink, a wire mesh screens out any large twigs etc., and then a sand and gravel bed filter out any other solid bits.
What percentage of nitrogen gas is in the atmosphere?
78.1%
Explain what is meant by the enhanced greenhouse effect.
The release of additional greenhouse gases by human activities. This has the potential to cause the average temperature on Earth to rise.
What was the early atmosphere composed of?
Gases released by volcanoes - mainly carbon dioxide and water vapour, with some methane and nitrogen.
What is potable water?
Water that is safe to drink.
What is the main source of the pollutant carbon monoxide?
Incomplete combustion of fossil fuels.
How is the pollutant sulfur dioxide produced? What are its effects?
Comes from sulfur impurities in fuels when burned.
Forms acid rain. Can also cause respiratory problems.
How is the pollutant nitrogen dioxide formed? Why is it harmful?
Comes from NO reacting with more oxygen in the air.
Causes acid rain, erodes stonework, killing trees and corrodes metal. Can also cause respiratory problems.
How is the pollutant NO formed? Why is it harmful?
Nitrogen and oxygen react together at high temperatures in vehicle engines.
Causes acid rain as NO2.
How are carbon particulates formed? Why are they harmful?
Carbon particulates are released as a result of incomplete combustion. Causes breathing problems and increases teh chance of heart disease.
Outline how the greenhouse effect works.
1 - The sun emits short wavelength infrared radiation, which enters the Earth’s atmosphere and travels towards it.
2 - The Earth absorbs shorter wavelength radiation but reflects the longer wavelengths.
3 - The longer wavelength radiation is then absorbed by greenhouse gases, which then re-radiate this as heat energy, some of which heads back to Earth. This then increases the Earth’s temperature.
