P2-Topic 9- Chemistry of the atmosphere Flashcards
Describe the proportions of gases in
the modern atmosphere 3
80% of N2
20% of O2
Small quantities of CO2, H2O, and noble gases
Describe the Earth’s early atmosphere and how it was formed 4
a) The Earth was hot when it was formed
b) intense volcanic activity released gases
that formed the early atmosphere
c)water vapor that condensed
to form the oceans
d) Gases have been released from these volcanoes
e) These gases included CO2, N2, CH4, NH3, H2O
how were sediments produced in the early atmosphere 2
When the oceans formed carbon dioxide dissolved in the water and
carbonates were precipitated producing sediments,
reducing the
amount of carbon dioxide in the atmosphere
How did the amount of oxygen in the atmosphere increase?
Algae and plants produced the atmospheric O2
by photosynthesis
Over billion
years plants evolved and the percentage of oxygen gradually
increased to a level that enabled animals to evolve.
How did the amount of carbon dioxide in the atmosphere
decrease? 3
a) Some CO2
was dissolved in the oceans, where it reacted with metal ions to form
insoluble carbonates, such as CaCO3
b) by the formation of sedimentary rocks that contain carbon (e.g. limestone and coal)
c) by the production of fossil fuels from the remains of dead plants and animals when they decayed
What are greenhouse gases?
and examples 3
gases in the atmosphere that maintain temperatures on Earth high
enough to support life
. Water vapour, carbon dioxide, and methane
What is the greenhouse effect?
They allow short wavelength radiation from the sun to pass through the
atmosphere to the Earth’s surface, but absorb the outgoing long wavelength
radiation from the Earth causing an increase in temperature.
what is short wave length radiation and long wave length radiation?2
short= ultraviolet (uV), visible light
long wavelength = infared
Why is the greenhouse effect
necessary for life?
The greenhouse effect is a natural phenomenon. Without it, the Earth would be too
cold for life to exist
How have human activities led to an increase in
greenhouse gases? 4 examples
2
Carbon dioxide – combustion and deforestation
Methane – increased farming and decomposition in landfill
examples of human activities that have led to climate change 4
Driving (CO2
Consuming electricity (CO2
Raising livestock (cows – CH4)
Decay of organic waste in landfill sites (CH4
why is it difficult to model global climate change 2
it is difficult to model such complex systems
leads to simplified models, speculation and opinions presented in the media that may be based on only parts of the evidence and which
may be biased.
What are the potential effects of global climate
change? 6
- sea level rise, which may cause flooding and increased coastal erosion
- more frequent and severe storms
- changes in the amount, timing and distribution of rainfall
- temperature and water stress for humans and wildlife
- changes in the food-producing capacity of some regions
- changes to the distribution of wildlife species
What is a carbon footprint?
A carbon footprint is the total amount of carbon dioxide and other greenhouse
gases emitted over the full life cycle of a product, service or event.
What actions can be taken to reduce a carbon footprint?6
- increased use of alternative energy supplies
- energy conservation
• carbon capture and storage (where CO2 is trapped in solvents and stored
underground)
- carbon taxes and licences
- carbon off-setting including through tree planting
- carbon neutrality – zero net release
