About 3.5 billion years ago, simple organisms in the oceans began to photosynthesise. This changed the Earth's atmosphere.
Balance the equation for photosynthesis.
...CO2+...H2O→C6H12O6+...O2\mathrm{CO_{2}} + ...\mathrm{H_{2}O} \rightarrow \mathrm{C_{6}H_{12}O_{6}} + ...\mathrm{O_{2}}CO2+...H2O→C6H12O6+...O2
Calculate the volume of oxygen, at room temperature and pressure, produced when algae make 45.0 g of glucose, C6H12O6\mathrm{C_{6}H_{12}O_{6}}C6H12O6.
Relative formula mass of glucose = 180. The volume of one mole of any gas at room temperature and pressure is 24 dm³.
Explain how the Earth's atmosphere changed from the early atmosphere to the atmosphere today.
97 exam-style questions on Edexcel GCSE Chemistry 9.2 Earth and atmospheric science, covering 9.2.1 The Earth's early atmosphere, 9.2.2 How the atmosphere evolved, 9.2.3 Chemical test for oxygen, and 9.2.4 The greenhouse effect and climate change. Each one has a worked solution and a mark scheme showing where the marks go.