chemistryTopic 9 · Chemistry of the AtmospherePaper 2Grades 8–9
Which city air-quality policy will have the greatest impact?
Starting scenario
Transport contributes 54% of city NOx, domestic heating 31% of particulates and industry 46% of sulfur dioxide. A low-emission zone cuts roadside NOx by 22% but traffic rises outside the zone. Replacing gas boilers reduces local pollutants but electricity demand increases.
You will work through 8 staged questions that build up the science you need. Then you will answer one big-picture question from memory, with no checklist to help you — and only afterwards will the full connection map be revealed.