Chemistry Flashcards
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
CO2 and other gases in the atmosphere help to keep the Earth warm. State how these gases keep the Earth warm.
Gases in the air absorb energy from infrared waves. When the gases re-emit the energy, some of it goes back to the Earth’s surface and warms it.
State 3 human activities that cause climate change
- Burning of fossil fuels
- Live stock farming
- Extracting oil from the ground
How does livestock increase levels of greenhouse gases in the atmosphere?
Cattle produces a lot of methane due to bacteria in their stomachs to digest tough grass
Describe why an increasing world population might lead to more greenhouse gases being released into the atmosphere?
There will be more farming to feed more people, more waste collecting and increase of burning fossil fuels due to more drivers.
List 4 negative effects of climate change
- raised sea levels due to melting glaciers
- some animals and plants may become extinct
- areas will become drier, others wetter
- harm living organisms in sea and oceans
Explain why an increased use of renewable energy might help to limit the impact of climate change?
It can reduce greenhouse gas emissions
Explain why international cooperation is important in dealing with climate change
Countries will need to work together to reduce emissions and help pay for large-scale engineering as there is a risk that some countries will not help and delicate eco-systems may be disrupted
Identify a way of limiting the impact of climate change and one risk
Helping local people adapt to new conditions e.g flood defences, dams and irrigation systems. However not everyone will cooperate
