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This quiz contains 5 questions from a mix of 1 subtopics.
plants / fossil / photosynthesis / died / organisms
Biofuels are mostly made from recently living , such as and algae. But they can also be formed from animal waste.
This is in contrast to fuels, which are made from organisms which millions of years ago.
In both cases though, plants and algae can trap the suns energy as part of , and this energy is released when we combust the fuel.
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What are the advantages of biofuels?
(Select all that apply)
They're renewable
They require a large area of land to grow
They can be used in cars
They're easy to transport
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What are the disadvantages of biofuels?
(Select all that apply)
They require a lot of energy to harvest, process and transport
They're relatively cheap to make
They're renewable
They require a large area of land to grow
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What do we mean when we say that 'biofuels are carbon neutral'?
They don't produce carbon dioxide when we burn them
They absorb carbon dioxide as we burn them
They absorb the same amount of carbon dioxide while growing, as they release when they're burned
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In theory biofuels should be carbon neutral, but in reality they are not.
Why is this?
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