Chemistry Of The Atmosphere Paper 2 Flashcards
What are the proportions of different gases in the earths atmosphere today
About 80% nitrogen
About 20% oxygen
Small proportions of other gases E.g. carbon dioxide, water vapour and Nobel gases
Why is the evidence of the early atmosphere limited
Because of the time scale of 4.6 billion years
How did oxygen increase
Algae and plants produced the oxygen that is now in the atmosphere by photosynthesis
How did carbon dioxide decrease
Algae and plants decreased the amount of oxygen in the atmosphere by photosynthesis. Carbon dioxide was also decreased by the formation of sedimentary rocks and fossil fuels that contains carbon
dead algae and plants turned into fossil fuels
What are the green house gases
Water vapour, carbon dioxide and methane
How do greenhouse gases support life
Maintain temperatures on earth
What human activities increase the amount of greenhouse gases in the atmosphere
Deforestation release CO2
Farming cattle release methane
Burning fossil fuel releases CO2
Farming rice in paddy fields releases methane
What are the effects of global climate change
Sea levels rising
Loss of habitats
Floods or droughts due to patterns of rainfall changing
Glaciers and polar ice melting
What are the problems caused by increasing the amounts of pollutants in the air
Sulphur dioxide and oxides of nitrogen cause respiratory problems in humans and causes acid rain.
Carbon monoxide is a toxic,colourless and odourless gas so it’s not easily detected
Particulates limit the amount of light that can reach the Earth’s surface so global dimming
Explain the greenhouse effect
Electromagnetic radiation that most wavelengths passes through the earths atmosphere.
The Earth absorbs most of the radiation warms up.
The Earth radiates energy as infrared radiation. Some of the infrared radiation goes into space. Some of the infrared radiation is absorbed by greenhouse gases in the atmosphere.
The lower atmosphere warms up.
How did volcanoes help form the atmosphere?
volcanoes released water vapour, carbon dioxide, and nitrogen into the
water vapour then cooled and condensed to form oceans atmosphere was mainly carbon dioxide with little or no oxygen and methane similar to venus
