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Key points

  • Carbon dioxide is a . Its molecules consist of one carbon atom joined to two oxygen atoms.

  • In the atmosphere, carbon dioxide is a .

  • We use carbon dioxide to make drinks fizzy and keep foods fresh.

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The Chemistry of carbon dioxide

Get an introduction to the chemistry of carbon dioxide from a development engineer.

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Structure and properties

carbon dioxide molecule

At room temperature carbon dioxide is a colourless and odourless .

The carbon dioxide is made up of one carbon (C) atom joined to two oxygen (O) atoms. This means it has a chemical formula is 䰿₂.

carbon dioxide molecule
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䰿₂ in the atmosphere

The amount of carbon dioxide in the is maintained through a balance.

Processes that increase the amount of 䰿₂ in the air include:

  • of petrol and diesel in cars
  • of living things

Processes that decrease the amount of 䰿₂ in the air include:

  • by plants
  • in sea water
The earth's atmosphere
Image caption,
The main gases that contribute to the greenhouse effect are carbon dioxide, methane and water vapour.

Carbon dioxide makes up less than 1% of the atmosphere; however, it is an important greenhouse gas.

This means that its molecules in the atmosphere absorb heat radiation from, keeping the Earth warmer than it would otherwise be.

For the past 100 or so years, carbon dioxide has been added to the atmosphere more quickly than it is removed. The extra carbon dioxide contributes towards .

Global warming leads to climate change, including more frequent droughts and stronger storms.

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Test your knowledge

Carbon dioxide quiz

Find out how much you know in this quick science quiz!

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Play the Atomic Labs game! game

Try out practical experiments in this KS3 science game.

Play the Atomic Labs game!
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More on The Earth and atmosphere

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