The Earth’s Atmosphere Flashcards
What was the atmosphere like billions of years ago?
Mainly carbon dioxide, nitrogen, water vapour and hydrogen based compounds
What did volcanoes release in the early atmosphere?
Carbon dioxide, water vapour and nitrogen
What happened when the Earth cooled?
Water vapour condensed and formed oceabs
How else was water brought to Earth?
Comets
What appeared 3.4 billion years ago?
Bacteria like organisms that used chemosynthesis to make energy
When did bacteria like organisms evolve into photosynthesising bacteria and algae?
2.7 billion years ago
How did photosynthesising organisms change the atmosphere?
By adding oxygen
What happened when plants and animals began to evolve?
Oxygen levels increases and carbon dioxide levels decreased
How much nitrogen is in the atmosphere today?
78%
How much oxygen is in the atmosphere today?
21%
How much carbon dioxide is in the atmosphere today?
0.04%
How much argon is in the atmosphere today?
0.9%
How much of other gases is in the atmosphere today?
0.06%
Why did nitrogen levels build up?
Nitrogen is very unreactive
What is the equation for methane reacting with oxygen in the early atmosphere?
Methane + Oxygen —> Carbon Dioxide + Water
CH4 + 2O2 —> CO2 + 2H2O
What is the equation for ammonia reacting with oxygen in the early atmosphere?
4NH3 + 3O2 —> 2N2 + 6H2O
Why did carbon dioxide levels decrease?
It got trapped in organisms, fossils, crude oils, etc
What are the main greenhouse gases?
Carbon Dioxide, Methane and Water Vapour
What are the fossil fuels?
Coal, oil and gas
What is the equation for burning fossil fuels?
Fossil fuels + oxygen —> carbon dioxide + water
What increases carbon dioxide in the atmosphere?
Burning wood, cattle farming, burning fossil fuels, deforestation
What is air pollution?
The presence of harmful substances in the environment
How does carbon dioxide affect the environment?
Climate change, raises earth’s temperature by trapping infrared radiation
How does carbon monoxide affect the environment?
Decreases the ability of the blood to carry oxygen leading to death
Where does carbon monoxide come from?
Incomplete combustion of fossil fuels
Where does sulphur dioxide come from?
Burning fossil fuels containing sulphur
How does sulphur dioxide affect the environment?
Combines with water vapour in the air to cause acid rain
How do nitric oxides affect the environment?
Combine with water vapour to form acid rain
Where do nitric oxides come from?
Lightning, road traffic, power plants
Where do particulates come from?
Burning fossil fuels and wood
How does particulates affect the environment?
Cause breathing difficulties, global dimming, dirty looking environment
