Chemistry Flashcards
(32 cards)
What gases were in the Earth’s early atmosphere?
- Mainly carbon dioxide
- Smaller amounts of water vapour and other gases
- Little or no oxygen
How do volcanoes affect the atmospheres of planets?
Release large amounts of gases such as carbon dioxide and water vapour, and small amounts of other gases (including nitrogen).
Why does the discovery of Titan’s icy interior not support the idea that the Earth’s early atmosphere was mainly nitrogen?
There is 98.4% of nitrogen which is likely to be released from volcanoes however it is covered in ice.
Why do scientists think that the early Earth had an atmosphere similar to Venus?
The atmosphere is mainly carbon dioxide, thought to have been released by volcanoes.
Describe how the Earth’s oceans may have formed?
Water vapour from the atmosphere condensed to liquid water
What evidence supports the idea that oxygen was not present in the early Earth’s atmosphere?
Oxygen is not produced by volcanoes.
Why are scientists more certain about the oxygen content of the early atmosphere compared to other gases?
They think oxygen from microorganisms reacted with iron in the early oceans, to produce insoluble iron oxides that formed layers on the seabed.
The percentage of carbon dioxide in the Earth’s atmosphere today is ….?
0.04%
The percentage of oxygen in the Earth’s atmosphere today is …?
21%
The percentage of nitrogen in the Earth’s atmosphere today is…?
78%
The percentage of argon in the Earth’s atmosphere today is …?
1%
What are the 3 phases of the evolution of the atmosphere?
1) volcanoes gave out carbon dioxide and water vapour into the atmosphere
2) photosynthesising organisms took in CO2 and released O2
3) more complex organisms can evolve with presence of O2
What has caused CO2 levels to decrease?
- photosynthesising organisms used CO2 (and released O2)
- CO2 dissolved in oceans
- organisms in oceans used CO2 to form
- CACO3 (calcium carbonate) to form shells
What has caused CO2 levels to increase?
Human activity - burning fossil fuels e.g fuel in cars, or in factories
Test for carbon dioxide
- bubble through limewater
- if solution goes cloudy, CO2 present
Test for oxygen
- glowing splint in gas
- relights if O2 present
State the greenhouse gases
- carbon dioxide
- methane
- water vapour
What is the influence of the greenhouse effect?
Makes the temperature hotter
Why might have industrialisation have led to an increase in greenhouse gases?
There was a steady increase in burning fuels such as factories. Meaning that carbon dioxide would’ve been released during combustion.
What is global warming?
Increase in the overall temperature of the Earth’s atmosphere
Compare global warming to climate change
Global warming is a cause of climate change which is changes to average weather conditions around the world.
What is a ‘casual link’?
A link that ‘one thing causes another’`
Why do many scientists believe that there is a casual link between CO2 level increase and a rise in temperature?
Satellite data confirms that as CO2 levels have increased, there has been a reduction in infrared waves from the Earth leaving the atmosphere
How do scientists measure CO2 levels from the past?
Measuring concentrations of the gas trapped in ice cores
