C9 - Chemistry of the Atmosphere Flashcards
How did the early atmosphere form?
Volcanoes erupting gases.
What was the original atmosphere made up billions of years ago?
Mainly carbon dioxide, volcanoes produced:
Nitrogen, water vapour, little methane & ammonia.
How were oceans formed?
The water vapour in the atmosphere condensed.
What happened to carbon dioxide when oceans formed?
It dissolved and formed carbonate precipitates that formed sediments on the sea bed.
How did carbon dioxide levels decrease?
Green plants and algae used it in photosynthesis.
How are fossil fuels formed?
- Plants, animals, plankton die.
- These are buried by layers of sediment.
- It becomes compressed and forms sedimentary rock.
How did oxygen levels increase?
Photosynthesis by green plants and algae.
When did our modern atmosphere start?
About 200 million years ago the atmosphere was similar to how it is today. (80% nitrogen, 20% oxygen, less than 1% other gases).
What did our modern atmosphere cause?
More complex life could develop/evolve e.g animals
How do greenhouse gases play a role in climate change?
Gases absorb longwave radiation then re-radiate it in all directions - including to Earth.
Describe the greenhouse effect.
Longwave radiation is thermal radiation so heats the Earth when it is re-radiated from gases in the atmosphere.
Give 2 human activities that contribute to greenhouse gases in the atmosphere.
Any of:
- Deforestation - less CO2 being photosynthesised.
- Burning fossil fuels - releases carbon as dioxide.
- Agriculture - methane produced from digestive system.
- Creating waste - C02 and methane produced.
Give 2 consequences of climate change.
Any of:
- Polar ice caps melting = flooding, sea levels rise, coastal erosion
- Change in rainfall pattern - difficult for food produce
- Increased frequency and severity of storms
- Change in species distribution.
Why is the Earth’s climate hard to understand?
It is so complex with so many variables.
Define carbon footprint.
Total greenhouse gases released over a life cycle of a product.
Why is carbon footprint hard to measure?
Many factors should be considered so it’s almost impossible to measure. This means it’s a rough estimate.
Give the 4 stages considered in carbon footprint.
- Sourcing the materials
- Making the product
- Using the product
- Disposal
Give 3 ways to reduce carbon footprint.
- Use renewable/nuclear energy sources
- Use efficient methods to conserve energy and reduce waste
- Create a tax or law based on emissions.
What are the cons of attempting to reducing carbon footprint? (3)
- Can harm the progress of developing countries and economies
- Hard to make everyone agree
- People need to accept it as part of their lifestyle
What does complete combustion release into the atmosphere?
Carbon dioxide and water vapour.
What does incomplete combustion release into the atmosphere?
Particles of soot and unburnt fuel produce carbon monoxide and dioxide during incomplete combustion.
What harm can particulates cause? (2)
- Respiratory problems - stuck in the lungs
2. Global dimming - produces clouds that reflect the sunlight back into space, this means less sunlight to Earth.
Give 2 dangers of carbon monoxide.
- Binds to haemoglobin instead of oxygen. This can cause fainting, a coma or death.
- It’s hard to detect as it’s colourless and odourless
What happens when sulfur or nitrogen combust?
They become sulfur dioxide/nitrogen oxide.
