The main gases in air
The main gases in air
The atmosphere is the thin layer of gases held around Earth by gravity. In clean, dry air, nitrogen, N2\text{N}_2N2, makes up about four-fifths, or approximately 80%80\%80%.
Step-by-step lessons on AQA GCSE Chemistry 9.1.1 The proportions of different gases in the atmosphere. Each one builds up to exam-style questions. Nail the core quantitative topics — moles, balancing equations and calculations — early on, since they underpin higher-tier questions across every paper and topic.