The main gases in air
The main gases in air
The atmosphere is the thin layer of gases held around Earth by gravity. Clean, dry air is made mostly of nitrogen, N2\text{N}_2N2, and oxygen, O2\text{O}_2O2.
Step-by-step lessons covering AQA GCSE Chemistry 9.1.1 The proportions of different gases in the atmosphere for Foundation and Higher tier. Each lesson works through exam-style questions in Paper 1 and Paper 2 format. Nail the core quantitative topics — moles, balancing equations and calculations — early on, since they underpin higher-tier questions across every paper and topic.