9-Chemistry of the Atmosphere (2)

Question 1

What was the Earths early atmosphere like?

Answer 1

• surface covered in volcanos that erupted and released lots of gases
• Early atmosphere mostly carbon dioxide, virtually no oxygen
• volcanic activity also released nitrogen which built up over time, as well as water vapour and small amounts of methane and ammonia

Question 2

How did the atmosphere develop?

Answer 2

• water vapour in atmosphere condensed to form oceans
• lots of carbon dioxide dissolved into oceans and removed from atmosphere - carbon in oceans formed carbon precipitates that formed sediments on the seabed
• green plants and algae evolved and absorbed some carbon dioxide for photosynthesis
• Marine animals evolved snd shells and skeletons contained carbonates from the oceans, some of the carbon from these became locked up in rocks and fossil fuels after organism died

Question 3

What is the atmosphere like now?

Answer 3

• ## green plants and algae produced oxygen from carbon dioxide using photosynthesis

Question 3

What is the atmosphere like now?

Answer 3

• green plants and algae produced oxygen from carbon dioxide using photosynthesis
  – as oxygen levels built up more complex plants and animals evolved

Question 4

What are carbon footprints?

Answer 4

• a basic measure of the amount of carbon dioxide and other greenhouse gases released over the full life cycle of something, can be a service, event or product
• need to consider sourcing of all the parts, emissions when using product and disposal of product

Question 5

How can carbon footprints be reduced?

Answer 5

• renewable energy sources or nuclear energy
• more efficient processes that could conserve energy and cut waste, lots of waste decomposes to give off methane - governments tax companies or individuals based on how much carbon dioxide they emit

Question 6

What is air pollution like?

Answer 6

• produced by combustion of fossil fuels such as crude oil, contain hydrocarbons, during combustion carbon and hydrogen in these compounds oxidised so carbon dioxide and water vapour released into atmosphere
• incomplete combustion releases carbon monoxide

Question 7

Why is air pollution a problem?

Answer 7

• if particles inhaled, can get stuck in the lungs and cause damage, lead to respiratory problems
• bad for environment reflect sunlight back into space so less light reaches earth
• carbon monoxide can stop your blood carrying oxygen as it binds to haemoglobin in your blood - less oxygen transported around body, cause fainting, coma or death, doesnt have colour or smell-extremely difficult to detect