Chemistry Of The Atmosphere Flashcards
How long have the proportions of the gases in the atmosphere been like today
200 million years
What are the gases found in today’s atmosphere (5)
Nitrogen,oxygen,carbon dioxide,water vapour,noble gases
What are the percentages of the gases in today’s atmosphere
Nitrogen = 80% Oxygen = 20% Other gases = <1%
What timescale is evidence for the early atmosphere limited too
4.6 billion years ago
What theory is given for the earth’s early atmosphere
- First billion years intense volcanic activity released lots of CO2 and water vapour 2. When the earth cooled the water vapour condensed to form oceans 3. Over time carbon dioxide levels started to decrease 4. Algae and plants evolved 5. Oxygen levels started to increase and animals were able to evolve
What planet is the earths early atmosphere suggested to be like
Mars and Venus, consisting mainly of carbon dioxide and little to no oxygen
What other gas was released by volcanoes
Nitrogen N2,methane CH4,ammonia NH3
What are the four ways carbon dioxide levels were reduced
- Dissolved into oceans 2. Plants took it in for photosynthesis 3. Carbonates precipitated producing sediments 4. Locked in fossil fuels
How did the percentage of oxygen increase in the early atmosphere
Algae and plants released it during photosynthesis
What is the word equation for photosynthesis
Carbon dioxide + water —> glucose + oxygen
What is the balanced symbol equation for photosynthesis
6CO2 + 6H2O —> C6H12O6 + 6O2
When did algae first appear?
2.7 billion years ago
What did the increase in oxygen from algae and plants lead to
Enabled animals to evolve
What useful substances have been formed as carbon dioxide decreased
Limestone,coal,crude oil, natural gas
What type of gas maintains the temperature on earth to be high enough to support life
Greenhouse gases
Examples of greenhouse gases
Water vapour,carbon dioxide,methane
Describe the greenhouse effect
The sun emits short wavelength radiation which passes through the earth’s atmosphere and is absorbed by the earth’s surface ,the earth emits long wavelength radiation back towards space,some gets trapped by greenhouse gases causing earth to heat up more
What green house gases are increased due to human activity
Carbon dioxide and methane
What human activities are increasing the level of carbon dioxide and methane
CO2 increases: burning fossil fuels,deforestation
Methane increases: farming cattle,rice paddy fields,landfill sites
What do scientists believe human activity will do to the Earths’s temperature
Increase it leading to climate change
What is the temperature of the earth increasing normally referred to as
Global warming
Why is it difficult to predict global warming
Based on simply models,speculation and opinion presented in the media
What is the issue with climate change presented in the media
Based on opinion,speculation only parts of evidence reported can be biased
What are the main four potential effects of global climate change?
Glaciers/ice caps melting,sea levels rising,rainfall patterns changing - causing droughts and floods,habitats changing
