Paper 2- Unit 9 Chemistry of the atmosphere Flashcards
What is the composition of the atmosphere today?
Nitrogen 80%
Oxygen 20%
Trace- water vapour, noble gases, carbon dioxide
What are the composition of gases in the early atmosphere
mainly carbon dioxide
some water vapour
little oxygen
Where did the early atmosphere come from?
Intense volcanic activity released gases including:
water vapour
methane
ammonia
How did the oceans form?
Water vapour cooled
condensed to make the oceans
Word equation for photosynthesis
Carbon dioxide + water –> Oxygen + glucose
Where did the oxygen in the atmosphere today come from?
algae formed (2.7 billion years ago)
started to photosynthesise
Why did the % of CO2 decreases from the early atmosphere
Carbon dioxide dissolved in the ocean
and form carbonate rock
Plants photosynthesise
lock up carbon
Fossil fuels formed over millions of years
lock up carbon
What is a green house gas?
they absorb infra red
raises global temperature (known as global warming)
Name 3 green house gases
Water vapour
Carbon dioxide
Methane
What processes produce methane?
Rice paddies
methane from cattle farming
Why have green house gases slowly increases in the last 100 years?
Combustion of fossil fuels
Deforestation
More rice paddies/cattle farming
What causes climate change?
Increases global temperature
caused by greenhouse gases
What are particulates?
Solid (unburnt) hydrocarbons
Problem with carbon monoxide
Toxic gas
Silent killer
Problem with carbon dioxide
Green house gases
contributes to global warming
