Jono keeps breathin' and breathin' and breathin' as he talks about oxygen and carbon dioxide for your GCSE chemistry exam. In this episode, he will look at how the proportions of oxygen and carbon dioxide have changed in the atmosphere and why. Excited? You should be.  Ideal for preparing your for GCSE Chemistry exam.  For more info visit https://www.senecalearning.com/blog/gcse-chemistry-revision/