chemistryTopic 4 · Chemical ChangesPaper 1Grades 8–9
How should a coastal town protect steel infrastructure?
Starting scenario
Three coatings are tested for 30 days. Paint reduces mass loss by 72% but fails when scratched. Zinc coating reduces loss by 94% and still protects scratches. Copper coating accelerates rust near scratches. The town also needs to extract and recycle metals for repairs.
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.