Topic 9 Chemistry Of The Atmosphere Flashcards
When did the atmosphere reach a composition similar to what it is today?
200 million years ago
Approximately how much nitrogen is in the atmosphere?
80%
Approximately how much oxygen is in the atmosphere?
20%
What 3 other gases make up less than 1% of the atmosphere?
Carbon dioxide
Water vapour
Noble gases
What is a theory on how the early atmosphere was formed?
Intense volcanic activity released gases
What 6 gases probably made up the early atmosphere and what was their composition?
Mostly carbon dioxide
Virtually no oxygen
Nitrogen, built up over time
Water vapour
Small amounts of methane and ammonia
Which 2 planets was the early atmosphere probably similar to?
Mars and Venus today
How were the oceans formed?
Water vapour in atmosphere condensed
How was lots of carbon dioxide removed from the early atmosphere?
Dissolved in oceans
What happened to carbon dioxide after it dissolved in oceans?
Went through series of reactions, formed carbon precipitates, formed sediments
How was oxygen increased in the atmosphere?
Green plants and algae produced oxygen by photosynthesis
When did algae first evolve?
2.7 billion years ago
What evolved over the next billion years after algae?
Green plants
What could evolve as oxygen levels built up in the atmosphere over time?
Complex life (animals)
What do greenhouse gases in the atmosphere maintain?
Temperatures on earth high enough to support life
What is the carbon footprint?
Total amount of carbon dioxide and other greenhouse gases emitted over full life cycle of product/service/event
What are 4 gases/particles that contribute to air pollution released by burning fossil fuels?
Carbon monoxide
Particulates (Solid particles of Soot (carbon))
Sulphur dioxide
Nitrogen oxides
What are 2 problems caused by particulates?
Stuck in lungs if inhaled- respiratory problems
Reflect sunlight back into space- global dimming
