AQA · Chemistry · 8462
GCSE Chemistry: How carbon dioxide decreased
Chemistry of the atmosphere · AQA GCSE Chemistry (8462), specification point 4.9.1.4. Cards are generated from the exam board's own specification for "How carbon dioxide decreased", and every card links back to the page it came from. Specification © AQA — used with attribution.
10 flashcards · Free to study · No account needed
Study this deck
Preparing your cards…
All questions and answers
Read through the full deck, or practise recalling each answer above.
Which process did algae and plants use to reduce atmospheric carbon dioxide?
Show answer
Photosynthesis — algae and plants absorbed carbon dioxide from the atmosphere to make glucose.
Algae and plants decreased the percentage of carbon dioxide in the atmosphere by ?.
Show answer
photosynthesis
Besides photosynthesis, what two types of carbon-containing deposits reduced atmospheric carbon dioxide?
Show answer
Sedimentary rocks (e.g. limestone) and fossil fuels (coal, crude oil, natural gas) — carbon became locked up in them.
How did the formation of sedimentary rocks reduce atmospheric carbon dioxide?
Show answer
Dissolved carbon dioxide formed carbonate precipitates (e.g. calcium carbonate) that settled as sediment, locking the carbon into rock such as limestone.
Which sedimentary rock is a key store of carbon removed from the early atmosphere?
Show answer
Limestone (calcium carbonate), formed from the shells and skeletons of marine organisms.
Name the three fossil fuels whose formation locked away carbon from the atmosphere.
Show answer
Coal, crude oil and natural gas.
From what material did coal deposits form?
Show answer
The remains of ferns and trees (plant material) buried in swamps, compressed and heated over millions of years without oxygen.
From what material did crude oil and natural gas form?
Show answer
The remains of plankton (tiny marine organisms) buried in mud on the sea floor, compressed and heated over millions of years.
Fossil fuels such as coal, crude oil and natural gas reduced atmospheric carbon dioxide because they ?.
Show answer
contain carbon
Why did the percentage of carbon dioxide in the early atmosphere fall dramatically?
Show answer
Photosynthesis by algae and plants absorbed it, and carbon was locked into sedimentary rocks and fossil fuels.
Want to create your own cards? Create a free account. AI generation uses credits.