GCSE Chemistry: Atmosphere & Resources — Deep Revision Workbook

Inside GCSE Chemistry: Atmosphere & Resources — Deep Revision Workbook

trace how the atmosphere evolved and give today's composition, explain greenhouse gases, the greenhouse effect and carbon footprint, identify the pollutants from burning fuels and their problems, work through potable water, waste water and life-cycle assessment, then cover reduce/reuse/recycle, phytomining, bioleaching and the Haber process, and finish with a full exam-style six-mark answer. About 45 minutes.

Learning objectives

• the evolution of the atmosphere — volcanic gases, oceans forming as water vapour condenses, algae and plants raising oxygen, and carbon locked into fossil fuels;
• greenhouse gases and carbon footprint — carbon dioxide, water vapour and methane, absorbing infrared, global warming and reducing a footprint;
• pollutants from burning fuels — complete and incomplete combustion, carbon monoxide, particulates and global dimming, and sulfur dioxide and oxides of nitrogen causing acid rain;
• using resources — finite versus renewable, potable and waste water, life-cycle assessment, reduce/reuse/recycle, phytomining, bioleaching and the Haber process;
• an extended six-mark answer on how the atmosphere has changed over time.

Activities in this book

1. Section 1 — The Evolving Atmosphere

   the early atmosphere formed from intense volcanic activity and was mostly carbon dioxide, with water vapour and little or no oxygen. As the Earth cooled, water vapour condensed to form the oceans, and carbon dioxide dissolved. Algae first produced oxygen about 2.7 billion years ago; then plants spread. Carbon was locked into sediments and fossil fuels, and nitrogen built up to about 78% of today's air.

2. Section 2 — Greenhouse Gases & Carbon Footprint

   the main greenhouse gases are carbon dioxide, water vapour and methane. They absorb infrared radiation re-emitted by the Earth's surface, warming the planet. Rising levels are linked to global warming and climate change. A carbon footprint is the total greenhouse gases released over the life of a product, service or event, and can be reduced. Scientists use models to make predictions.

3. Section 3 — Pollutants from Burning Fuels

   complete combustion of a hydrocarbon gives carbon dioxide and water. Incomplete combustion (too little oxygen) makes toxic carbon monoxide, which is colourless and odourless. Soot and unburnt fuel form particulates that cause global dimming and breathing problems. Sulfur impurities burn to sulfur dioxide, and high engine temperatures make oxides of nitrogen — both cause acid rain.

4. Section 4 — Using Resources: Water, LCA & Metals

   finite resources run out; renewable ones are replaced. Potable water is safe to drink — fresh water is filtered then sterilised (chlorine, ozone or UV); sea water is treated by distillation or reverse osmosis. A life-cycle assessment weighs whole-life impact. We reduce, reuse and recycle, extract metals by phytomining and bioleaching, and make ammonia for fertilisers by the Haber process.

5. Section 5 — The Changing Atmosphere (6 marks)

   this is an exam-style writing task, so it is not auto-marked. Aim for six clear points, using the correct keywords (volcanic activity, carbon dioxide, water vapour, oceans, photosynthesis, algae, oxygen, nitrogen) and one clear idea per line.

Suggestions for teaching

• Tell the atmosphere's story in order. Volcanoes → carbon-dioxide-rich air → oceans dissolve carbon dioxide → photosynthesis raises oxygen → today's stable mix.
• Separate the two atmosphere problems. Keep greenhouse gases and warming clearly apart from pollutants such as carbon monoxide, particulates, sulfur dioxide and oxides of nitrogen.
• Sequence water treatment. Choose a fresh source, filter to remove solids, then sterilise — and contrast distillation and reverse osmosis for sea water.
• Make resources concrete. Use real examples for recycling, phytomining and bioleaching, and link the Haber process to NPK fertilisers.