6 exam-style questions with full mark schemes and model answers. Write your own answer and the AI examiner marks it against the mark scheme.
Learn this properly: History of the AtmosphereBurning fuels in cars and power stations releases several substances into the atmosphere, including carbon dioxide, carbon monoxide, sulfur dioxide, oxides of nitrogen and particulates (soot).
Describe and explain how these substances are produced when fuels are burned, and describe one problem caused by each of: carbon dioxide, carbon monoxide and sulfur dioxide. (6 marks)
The pie-chart data below show the approximate composition of the dry air in today's atmosphere.
| Gas | Approximate percentage by volume / % |
|---|---|
| Nitrogen | 78 |
| Oxygen | 21 |
| Other gases (incl. carbon dioxide and noble gases) | 1 |
(a) Name the gas that makes up about 21% of the atmosphere, and state the approximate percentage of carbon dioxide in the atmosphere today. (2 marks)
(b) Scientists believe Earth's early atmosphere was very different. Name the main gas thought to have made up most of the early atmosphere, and name the process (carried out by early plants and algae) that increased the amount of oxygen. (2 marks)
Carbon dioxide and methane are greenhouse gases. Increasing their concentration in the atmosphere is linked to global warming.
(a) Name one greenhouse gas other than carbon dioxide and methane. (1 mark)
(b) Describe how greenhouse gases in the atmosphere help to keep the Earth warm. (2 marks)
Methane (CH4) burns completely in a good supply of oxygen.
(a) Write a balanced symbol equation for the complete combustion of methane. (2 marks)
(b) Explain why burning methane in a limited supply of oxygen can produce the toxic gas carbon monoxide. (1 mark)
The carbon footprint of a product is a measure of its impact on the climate.
(a) State what is meant by the carbon footprint of a product. (1 mark)
(b) Suggest one action a company could take to reduce the carbon footprint of manufacturing a product. (1 mark)
Sulfur dioxide and oxides of nitrogen released from burning fuels can cause a particular type of environmental damage when they mix with water in clouds.
Name the environmental problem caused by these gases. (1 mark)